Release 2026.10.04: payload size limit, dotted classifier keys

max_payload_bytes (default 64 KiB, None for no limit) bounds the arguments
and results stored in mode full and every event's attrs. A larger value is
stored as {"_truncated": true, "size": ..., "preview": ...}, the preview
taken from the redacted value. Call payloads reuse the size already
measured for args_size and result_size; attrs keep their keys, with only
the largest values replaced.

soft_error_classifier takes message_keys, and message_keys and error_keys
accept dotted paths into nested dicts ("snapshot.error"). An exact key is
matched before splitting; a missing or non-dict step is absent.

.env.example

@@ -0,0 +1,13 @@
+# Copy to .env (make does this for you on first run) and adjust as needed.
+COMPOSE_PROJECT_NAME=fastmcp-feedback-pkg
+
+FFB_PG_IMAGE=pgvector/pgvector:pg16
+FFB_PG_USER=ffb
+FFB_PG_PASSWORD=change-me
+FFB_PG_DB=ffb_test
+# Published on 127.0.0.1 only. 55432 is commonly taken by other local stacks.
+FFB_PG_PORT=55447
+
+# Read by the test suite. Unset, the Postgres test cases skip.
+# Each test gets its own database created on this server and dropped after.
+FFB_TEST_DATABASE_URL=postgresql+asyncpg://ffb:change-me@127.0.0.1:55447/ffb_test

.gitea/workflows/test.yml

@@ -0,0 +1,118 @@
+name: Tests
+
+# fastmcp-feedback declares fastmcp>=2.12.2,<5, so every version family in
+# that range gets the full suite. A user on PyPI gets the newest FastMCP the
+# range allows, not what uv.lock pins, which is how 2026.01.12.1 shipped with
+# composition broken on 2.14 and 4.x without anyone noticing.
+
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+  schedule:
+    # Weekly, so a new FastMCP release is caught even when nobody pushes
+    - cron: '17 9 * * 1'
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    strategy:
+      fail-fast: false
+      matrix:
+        fastmcp: ['==2.12.2', '==2.14.3', '>=3.3,<4', '>=4,<5']
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: astral-sh/setup-uv@v6
+        with:
+          python-version: '3.13'
+
+      - name: Install against fastmcp${{ matrix.fastmcp }}
+        run: |
+          uv venv
+          uv pip install -e ".[dev]" "fastmcp${{ matrix.fastmcp }}"
+          uv pip show fastmcp | grep -i '^version'
+
+      - name: Lint
+        run: uv run --no-sync ruff check src/ examples/ tests/_compat.py tests/_databases.py tests/unit/test_test_databases.py tests/unit/test_instrumentation.py
+
+      - name: Test
+        run: uv run --no-sync pytest -q --no-cov
+
+  # The DatabaseSink tests again, on Postgres + pgvector instead of SQLite.
+  # Oldest and newest supported FastMCP; the SQLite legs above cover the rest.
+  # act_runner runs the job in a container, so the service is reached by name.
+  test-postgres:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    strategy:
+      fail-fast: false
+      matrix:
+        fastmcp: ['==2.12.2', '>=4,<5']
+
+    services:
+      ffb-postgres:
+        image: pgvector/pgvector:pg16
+        env:
+          POSTGRES_USER: ffb
+          POSTGRES_PASSWORD: ffb-ci
+          POSTGRES_DB: ffb_test
+        options: >-
+          --health-cmd "pg_isready -U ffb -d ffb_test"
+          --health-interval 2s
+          --health-timeout 3s
+          --health-retries 30
+
+    env:
+      FFB_TEST_DATABASE_URL: postgresql+asyncpg://ffb:ffb-ci@ffb-postgres:5432/ffb_test
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: astral-sh/setup-uv@v6
+        with:
+          python-version: '3.13'
+
+      - name: Install against fastmcp${{ matrix.fastmcp }}
+        run: |
+          uv venv
+          uv pip install -e ".[dev]" "fastmcp${{ matrix.fastmcp }}"
+          uv pip show fastmcp | grep -i '^version'
+
+      - name: Test with the Postgres cases enabled
+        run: make test-pg
+
+      - name: Postgres cases ran rather than skipped
+        run: |
+          out=$(uv run --no-sync pytest -q --no-cov -m postgres -rs)
+          echo "$out" | tail -3
+          if echo "$out" | grep -q 'SKIPPED'; then
+            echo "Postgres cases skipped; is the service reachable?"; exit 1
+          fi
+
+  # Newest FastMCP with no ceiling. Allowed to fail: it exists to say
+  # "a new major version is out and here is what breaks" before users do.
+  canary:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    continue-on-error: true
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: astral-sh/setup-uv@v6
+        with:
+          python-version: '3.13'
+
+      - name: Install newest FastMCP, ignoring our ceiling
+        run: |
+          uv venv
+          uv pip install fastmcp "sqlalchemy[asyncio]" aiosqlite pydantic \
+            pytest pytest-asyncio pytest-cov pytest-mock pytest-html
+          uv pip install --no-deps -e .
+          uv pip show fastmcp | grep -i '^version'
+
+      - name: Test
+        run: uv run --no-sync pytest -q --no-cov

CHANGELOG.md

@@ -5,6 +5,598 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Calendar Versioning](https://calver.org/) (YYYY.MM.DD).
 
+## [2026.10.04] - 2026-10-04
+
+Bounded payloads, and classifier keys that reach into nested results.
+
+### Added
+- `max_payload_bytes` on `InstrumentationMiddleware` and `instrument()`,
+  64 KiB by default, `None` for no limit. Arguments and results stored in
+  mode `full`, and every event's `attrs` (including `record_llm_call`'s),
+  are bounded by it. A larger value is stored as
+  `{"_truncated": true, "size": <bytes>, "preview": "<start of its JSON>"}`;
+  the preview is 1000 characters (a quarter of the limit when smaller) and
+  is taken after redaction. Call payloads reuse the size already measured
+  for `args_size` and `result_size`, so the limit adds no encoding; the
+  preview encodes only the start of the value. In `attrs`, only the largest
+  values are replaced, so the dict keeps its keys. `EmbeddingSink` embeds a
+  marker's preview. `fastmcp_feedback.instrumentation.payload` holds the
+  marker helpers (`TRUNCATED`, `is_truncated`).
+- `message_keys` on `soft_error_classifier` (default `error`, `message`,
+  `detail`, `reason`, as before).
+- Dotted paths in `message_keys` and `error_keys`: `"snapshot.error"` reads
+  `result["snapshot"]["error"]`. A key that literally contains a dot is
+  matched first; a missing step or a non-dict step counts as absent and
+  never raises. Default outputs are unchanged.
+
+### Changed
+- Stored payloads and event attrs over 64 KiB become markers. Earlier
+  releases stored them whole; `max_payload_bytes=None` keeps that.
+
+## [2026.10.02.1] - 2026-10-02
+
+The identity resolver's second run is opt-in again for any resolver that
+answers.
+
+### Changed
+- The second resolver run after the tool now happens only when the first
+  answer was empty (no keys, only None values, or a run that failed or timed
+  out) or lacks a key in `late_identity_keys`. In 2026.10.02 a missing
+  `user_sub`, `caller_kind` or `client_id` also triggered it, so a resolver
+  that never returns one of them (mcspeak's returns no `client_id`) ran twice
+  on every kept call. `late_identity_keys` stays empty by default: a resolver
+  that answers anything runs once per call unless the server opts in.
+  blender-mcp's registration fix still needs
+  `late_identity_keys=["bus_client_uuid"]`, as in 2026.10.02.
+
+## [2026.10.02] - 2026-10-02
+
+A tool that creates its caller's identity records it on its own row again.
+
+### Fixed
+- Regression in 2026.10.01.4: with the identity resolver moved before the
+  tool, a call whose tool creates the identity the resolver looks up (the
+  call that registers a client, or logs in) recorded its own row without
+  it. blender-mcp's `register_client` lost `bus_client_uuid`, `bus_role` and
+  `parent_uuid` from its row's `identity` this way. When the first answer is
+  incomplete, missing `user_sub`, `caller_kind` or `client_id`, or any key in
+  the new `late_identity_keys`, the resolver now runs a second time after the
+  tool, concurrently with the enricher, for calls that are kept (not for
+  sampled-out ones). Its values fill the row's gaps and replace `None`; on
+  conflict the first answer wins, so the row matches the events recorded
+  during the call, which are not rewritten. Both runs keep `hook_timeout`,
+  redaction and never raising. A complete first answer still means one run.
+
+### Added
+- `late_identity_keys` on `InstrumentationMiddleware` and `instrument()`:
+  identity keys that may only exist once the tool has run. A resolver that
+  already returns all three columns before such a tool (blender-mcp's does)
+  needs it to get the second run, e.g.
+  `late_identity_keys=["bus_client_uuid"]`.
+
+## [2026.10.01.4] - 2026-10-01
+
+Statistics speak the same enum values as the rest of the API, events carry
+the caller's identity, and importing the package no longer configures
+logging.
+
+### Changed
+- `get_feedback_statistics` and `get_database_stats` key `by_type` and
+  `by_status` by enum value (`bug`, `in_progress`), the spelling
+  `list_feedback` returns and accepts as a filter. They grouped the raw
+  columns, which hold the enum NAMES on both SQLite (VARCHAR) and Postgres
+  (native enum types `feedbacktype`, `feedbackstatus`), so they returned
+  `BUG`, `IN_PROGRESS`. **Code reading the uppercase keys must switch to
+  lowercase.** Nothing stored changes. A row holding a value instead of a
+  name is counted under the same key; an unknown label is kept as-is.
+- The identity resolver runs once per call **before** the tool, instead of
+  after it. The call's record reuses the result (still redacted, still
+  limited by `hook_timeout`, still never raising). An async resolver can
+  therefore delay the tool by up to `hook_timeout`, and it now also runs for
+  ok calls that sampling drops afterwards. It does not run in mode `off` or
+  for `exclude_tools`. The enricher still runs after the call.
+- `PACKAGE_INFO` is read from the installed distribution's metadata. It
+  listed only the `postgresql` and `dev` extras and a classifier pyproject
+  did not have.
+- psycopg2-binary is in the `dev` and `test` extras, so `make test-pg`
+  covers the feedback tools on Postgres too.
+
+### Fixed
+- `record_event` (and `record_llm_call`) inside a tool call never set
+  `user_sub`, `caller_kind` or `client_id`, because identity was resolved
+  only after the call. Inside a call they now come from the call's resolved
+  identity, matching its row; `client_id` falls back to the FastMCP context's
+  as for calls. Values passed explicitly win, and `record_event` takes
+  `caller_kind=` and `client_id=` as well as `user_sub=`. Outside a call,
+  including a task the call started that records after it returned, nothing
+  is filled in.
+- Importing `fastmcp_feedback` called `logging.basicConfig` at INFO when the
+  root logger had no handlers, so every host process (the backfill CLI
+  included) printed an "initialized" line and had its root logger set up by
+  a library. The package now only adds a `NullHandler` to the
+  `fastmcp_feedback` logger and logs the version at DEBUG. **Servers that
+  relied on the package's INFO or WARNING lines must configure logging
+  themselves**; `fastmcp_feedback.setup_logging()` restores the old
+  behavior in one line.
+- The backfill CLI logs a summary of its counts at INFO, so `-v` shows
+  something on a dry run.
+
+### Documentation
+- README: statistics keys, identity resolver timing, a Logging section, the
+  two Postgres driver paths (`[postgresql]` for the feedback tools,
+  `[instrumentation]` plus asyncpg for the sinks), MySQL marked untested,
+  and the measured coverage (95% lines and branches with the Postgres cases
+  enabled) in place of "98%".
+- CONTRIBUTING: the example test, the mixin recipe and the commands now
+  match the package and were run; `make test`, `make test-pg` and
+  `make lint` replace commands that did not pass on this repository.
+
+## [2026.10.01.3] - 2026-10-01
+
+### Documentation
+- The documentation site is public at https://fastmcp-feedback.supported.systems,
+  rewritten against this package with every example executed. The README
+  links and the PyPI "Documentation" URL point there instead of the private
+  dev address.
+
+## [2026.10.01.2] - 2026-10-01
+
+The instrumentation imports on a base install, without the database extras.
+
+### Fixed
+- `import fastmcp_feedback.instrumentation` failed on `pip install
+  fastmcp-feedback` without the `instrumentation` extra: the package imported
+  `storage.py` eagerly, which imports `sqlalchemy.ext.asyncio`, and SQLAlchemy
+  2.1 raises `ImportError` there when `greenlet` is missing. `instrument(app)`
+  with `JsonLinesSink`, `CallbackSink` or `MemorySink`, events, redaction and
+  result classification now need only the base dependencies.
+- `DatabaseSink`, `EmbeddingVector`, `build_metadata`, `Embedder`,
+  `EmbeddingSink`, `EmbeddingText`, `OpenAIEmbedder`, `extract_texts`,
+  `backfill_embeddings` and `backfill_feedback` load on first access. Without
+  the extra, accessing one raises `ImportError` naming the missing package and
+  the extra to install (`[instrumentation]`, or `[instrumentation,embeddings]`
+  for the embedding names), chained to the original error. Every access
+  raises, not only the first, although SQLAlchemy itself reports a missing
+  `greenlet` only once. Import paths are unchanged.
+- The middleware finds a `DatabaseSink` or `EmbeddingSink` among its sinks
+  without importing their modules, so `database_sink`, `embedding_sink`,
+  `capture_recent_calls`, `link_feedback`, `feedback_context`, `events_for`,
+  `similar` and `similar_feedback` return their usual empty results on a base
+  install.
+- `DEFAULT_TABLE_PREFIX`, `DEFAULT_EMBEDDING_DIM`, `EMBEDDING_SOURCES` and
+  `DEFAULT_EVENT_TEXT_KEYS` moved to `instrumentation/constants.py` and import
+  without the extras; `storage` and `embeddings` still export them.
+
+## [2026.10.01.1] - 2026-10-01
+
+A result that says it succeeded is no longer flagged for its own error string.
+
+### Changed
+- Explicit success flag wins over error keys: when any of the classifier's
+  `flag_keys` (`ok`, `success`) is exactly `True`, the `error_keys` check is
+  skipped and the string is treated as a warning, so
+  `{"ok": True, "error": "deprecated arg"}` is recorded as `ok` again. Only
+  that check is skipped: a failing status (`{"success": True, "status":
+  "failed"}`), any flag key exactly `False` and `isError` still flag the
+  result. Truthy values that are not `True`, such as `1` or `"yes"`, are not
+  an explicit success. Results with no flag key are classified as in
+  2026.10.01.
+
+## [2026.10.01] - 2026-10-01
+
+Results that report failure only as an `error` string now count as soft
+errors, and the docs cover joining events to calls.
+
+### Changed
+- `soft_error_classifier(..., error_keys=("error",))`: a dict result whose
+  value at any of `error_keys` is a non-empty string (after stripping) is a
+  soft error, with message `<key>: <string>`, redacted and truncated as
+  before. Checked after the status, flag and `isError` checks, so results
+  those already flag keep their message and are counted once. None, empty or
+  blank strings, numbers, booleans, dicts and lists do not count, so
+  `{"error": None}` and `{"error": 0.02}` stay ok. `error_keys=()` turns it
+  off. `DEFAULT_RESULT_CLASSIFIER` has it on.
+- **Behavior change:** results such as `{"played": False, "error": "..."}`,
+  `{"error": "..."}` and `{"status": "unknown_target", "error": "..."}` were
+  recorded as `ok` and are now `soft_error`, so `NOT ok` and soft-error
+  counts can rise after upgrading. This includes the package's own
+  `list_feedback`, `get_feedback_statistics` and analytics tools, whose
+  failure results carry an `error` string and no flag key. Pass
+  `result_classifier=soft_error_classifier(error_keys=())` for the old
+  behavior.
+
+### Docs
+- `record_event` / `events_for`: a `key` used for joining must be unique for
+  at least the retention period and across restarts; a per-boot counter
+  collides. Use a UUID or a startup token plus a counter.
+- The join from a call to its events through an enricher-written `extra`
+  field, for SQLite (`json_extract(c.extra, '$.speech_id') = e.key`) and
+  Postgres (`c.extra->>'speech_id' = e.key`).
+- Schema notes: `ffb_tool_calls` has primary key `id` and no `call_id`
+  column; `ffb_events.call_id` holds a call's `id`. Ids are UUIDs, so order
+  events by `occurred_at`.
+- The soft-error section documents `error_keys`, its default and the
+  upgrade note.
+
+## [2026.09.30.1] - 2026-09-30
+
+Embed what was stored before embedding was switched on, and embed list and
+dict attrs as text rather than as Python reprs.
+
+### Added
+- `await backfill_embeddings(embedding_sink, *, sources=None, since=None,
+  until=None, limit=None, batch_size=500, dry_run=False)`. Reads the
+  `DatabaseSink`'s tables for calls with outcome `error` or `soft_error`
+  (and, for rows from before the `outcome` column, outcome NULL with an
+  `error_message`), `feedback.submitted` events, `llm.call` events with
+  prompt or completion, and other events with any of the sink's
+  `event_text_keys`. Each record goes through the live sink's extraction,
+  redactor and `max_chars`, so text, `text_hash` and `source_id` match and
+  later records dedupe against backfilled rows. Idempotent: a second run
+  embeds nothing. Keyset-paged by timestamp and id, `batch_size` rows per
+  query; embeds in chunks of the sink's `batch_size`. `limit` embeds at most
+  that many texts, oldest first. Returns counts per source type plus
+  `skipped` and `errors`; embed failures are counted, never raised. Raises
+  only for bad arguments or a missing table. `sources` defaults to the
+  sink's.
+- `await backfill_feedback(embedding_sink, items, *, batch_size=500,
+  dry_run=False)` for feedback in the host's own tables, as
+  `(ref, title, description)` tuples; the same text a `feedback.submitted`
+  event with that ref gives.
+- `python -m fastmcp_feedback.instrumentation.backfill --database-url ...
+  --embed-base-url ... [--model --dim --prefix --sources --since --until
+  --limit --batch-size --max-chars --event-text-keys --create-tables
+  --dry-run]`. The API key comes from `FFB_EMBED_API_KEY` or the variable
+  named by `--api-key-env`. Prints counts as JSON; exits 1 when any text
+  failed, 2 on a setup error.
+
+### Changed
+- **Embedded text of list, tuple and dict values.** Lists and tuples are
+  embedded one cleaned, non-empty item per line instead of as their repr
+  (`"['a', 'b']"`); dicts as `key: value` lines, sorted by key because
+  PostgreSQL JSONB does not keep key order and a backfill must rebuild the
+  same text. Nested values are flattened the same way, to a depth of 32 and
+  about 64k characters before `max_chars` applies. This applies to event
+  text keys, feedback title and description, and LLM prompt and completion.
+  Existing rows embedded from such values keep their old text; a backfill
+  run replaces them, since their text changed.
+
+## [2026.09.30] - 2026-09-30
+
+Embed feedback, tool errors, event text and (opt-in) LLM text, and search
+them by meaning: "has anyone reported this before?"
+
+### Added
+- `EmbeddingSink(embedder, database_sink, *, sources=("feedback",
+  "call_error", "event", "llm"), event_text_keys=("error_excerpt", "error",
+  "message", "reason"), max_chars=4000, max_queue=1000, batch_size=32,
+  timeout=30.0, scan_limit=5000)`. `write` extracts text and puts it on the
+  sink's own bounded queue, returning at once, so a slow embedding backend
+  never reaches the dispatcher's `sink_timeout` or a tool call. A background
+  task embeds in batches and upserts through the `DatabaseSink`'s engine. A
+  full queue drops and counts (`dropped`); embedder and database failures are
+  logged and counted (`errors`), never raised. An unchanged text (same
+  `text_hash`) is not embedded again; a changed one replaces its row. Text is
+  redacted with the middleware's `Redactor` (adopted when the sink is passed
+  to `instrument`) and truncated before it leaves the process. `aclose()`
+  drains for up to `timeout`, then drops and counts the rest.
+- `Embedder` protocol (`model`, `dim`, `async embed(texts)`) and
+  `OpenAIEmbedder(base_url, api_key=None, model="mxbai-embed-large", dim=1024,
+  batch_size=32, timeout=30.0)` for any OpenAI-compatible `/v1/embeddings`
+  endpoint. It uses `httpx`, or `httpx2` under FastMCP 4; no new dependency.
+  A vector of the wrong length raises `ValueError`.
+- `await mw.similar(text, *, source_types=None, k=10, min_score=None)` and
+  `await mw.similar_feedback(feedback_ref, *, k=10, source_types=None,
+  min_score=None)`. Results carry `source_type`, `source_id`, `text`, `score`
+  (1 - cosine distance, clamped to [0, 1]) and `created_at`. PostgreSQL ranks
+  with `embedding <=> :q` on an HNSW index; other databases compare in Python
+  against the newest `scan_limit` rows. `similar_feedback` reuses the stored
+  vector and leaves the item itself out. Neither raises; failures log and
+  return [].
+- **Feedback flows as an event.** With `instrumentation=`, `submit_feedback`
+  records `feedback.submitted` keyed by the feedback id, with `type`, `title`,
+  `description` and `submitter`. Hosts with their own feedback tools record
+  the same event with their own ref (`bug-7Q2X`).
+- `InstrumentationMiddleware(capture_llm_text=False, max_llm_text_chars=None)`
+  and `record_llm_call(..., prompt=None, completion=None)`. Prompt and
+  completion are stored (redacted, cut to `8 * max_error_chars`, 4000 by
+  default) only when `capture_llm_text=True`.
+- `embeddings` extra: `pgvector>=0.5.0`. Postgres hosts also need `asyncpg`.
+- `build_metadata(prefix, metadata=None, embedding_dim=1024)` and
+  `DatabaseSink(embedding_dim=1024)`. `embedding_dim=None` in `build_metadata`
+  leaves the embeddings table out.
+
+### Changed
+- **New table `{prefix}embeddings`** (`id`, `source_type`, `source_id`,
+  `model`, `dim`, `text_hash`, `text`, `created_at`, `embedding`), unique on
+  (`source_type`, `source_id`, `model`). `embedding` is pgvector `vector(dim)`
+  with an HNSW `vector_cosine_ops` index on PostgreSQL, a JSON float list
+  elsewhere. `build_metadata()` now includes it, so Alembic hosts need a
+  migration; the README has the SQL, starting with
+  `CREATE EXTENSION IF NOT EXISTS vector`. With `create_tables=True` the table
+  is created when an `EmbeddingSink` first writes, not at startup, so hosts
+  that do not embed need neither pgvector nor the extension. On PostgreSQL
+  that step first runs `CREATE EXTENSION IF NOT EXISTS vector`; without the
+  privilege it logs a warning, keeps the sink running, and retries at most
+  once a minute.
+- `DatabaseSink.prune()` also deletes embeddings older than the cutoff,
+  except those of feedback, and returns the total from all three tables.
+- `record_llm_call` now drops `prompt` and `completion` keys passed in
+  `attrs` unless `capture_llm_text=True`. Earlier versions stored them.
+
+### Documentation
+- README: `DatabaseSink` needs the `instrumentation` extra even with
+  SQLAlchemy installed, since SQLAlchemy 2.1 no longer installs `greenlet`.
+
+## [2026.09.29.1] - 2026-09-29
+
+### Fixed
+- `DatabaseSink(create_tables=True)`: two processes starting at the same
+  moment against a database without the tables both ran `create_all`, and one
+  failed (SQLite: `table ... already exists`; Postgres: a unique violation on
+  `pg_type_typname_nsp_index`). That process dropped its first batch and
+  counted a sink error. `ensure_tables()` now waits 50 to 250 ms after a
+  database error and runs `create_all` once more, which skips what the other
+  process created; the recovery is logged at INFO. A second failure is raised
+  as before. Measured on two-writer cold starts: SQLite 9 of 10 runs lost a
+  batch before, 0 of 10 after; Postgres 16 12 of 12 before, 0 of 12 after.
+
+## [2026.09.29] - 2026-09-29
+
+Record things that are not tool calls: background job transitions, LLM
+requests a tool makes, anything with a dotted name.
+
+### Added
+- `mw.record_event(kind, *, key=None, attrs=None, user_sub=None,
+  call_id=None) -> bool`. Synchronous; never raises, never blocks. `attrs` is
+  redacted like call arguments and made JSON-safe (`NaN`/infinities become
+  strings, since Postgres JSONB rejects them). Returns False when the event
+  was not recorded: mode `off`, an empty or over-128-character `kind`, a `key`
+  over 255 characters, non-mapping `attrs`, a full queue, or no event loop.
+  Events share the call records' queue and drop-and-count policy.
+- **Linking to the running call.** The middleware now picks a call's record id
+  before the tool runs and exposes it through a ContextVar, so an event
+  recorded inside a tool gets that call's id as `call_id` (and its session),
+  matching the stored `ffb_tool_calls` row. Outside a call, `call_id` is None;
+  a task a tool started that records after the tool returned counts as
+  outside.
+- **Thread safety.** `record_event` works from any thread: off the server's
+  loop, the event is handed over with `call_soon_threadsafe`. The loop is
+  known from the first tool call (the dispatcher now binds to it as each call
+  starts), so sync tools running in FastMCP's worker threads link too. Before
+  any call or record, a thread with no loop of its own gets False and a
+  counted drop.
+- `mw.record_llm_call(*, model, provider=None, duration_ms=None,
+  input_tokens=None, output_tokens=None, ok=None, error=None, key=None,
+  attrs=None) -> bool` records kind `llm.call` with plain attribute names:
+  `model`, `provider`, `duration_ms`, `input_tokens`, `output_tokens`, `ok`
+  (defaults to `error is None`), `error` (redacted, truncated to
+  `max_error_chars`) and `error_type` for exceptions. The README maps them to
+  OTel GenAI names.
+- `await mw.events_for(key, *, kinds=None, limit=1000)`: a key's events, oldest
+  first (the newest `limit`), from the `DatabaseSink` plus events still in the
+  queue, deduplicated by id, `occurred_at` in UTC. Without a `DatabaseSink` it
+  answers from memory (`recent_events=2000` on the middleware).
+- `EventRecord`, exported from `fastmcp_feedback.instrumentation`.
+  `MemorySink` has `.calls` and `.events`.
+- Exclusion and sampling still apply to tool calls only. A sampled tool's call
+  that recorded an event is always kept (no `sample_rate`), so the event's
+  `call_id` has a row.
+
+### Changed
+- Sinks receive mixed batches of `ToolCallRecord` and `EventRecord` once
+  events are recorded. `record.record_type` is `tool_call` or `event`. A
+  `CallbackSink` callback that assumes every record is a call needs a check.
+- `JsonLinesSink` lines carry `"record": "tool_call"` or `"record": "event"`
+  (a new field; existing fields unchanged).
+- `DatabaseSink.write` stores calls and events in separate transactions,
+  calls first, so a database without the events table still stores calls.
+- `DatabaseSink.prune()` also deletes events whose `occurred_at` is before
+  the cutoff, in `prune_batch` batches, and **returns the total rows deleted
+  from both tables**; each table's count is logged. It skips events on a
+  database that has no events table.
+
+### Migration
+- New table `{prefix}events` (`ffb_events` by default): `id`, `occurred_at`,
+  `kind`, `key`, `call_id`, `session_id`, `user_sub`, `caller_kind`,
+  `client_id`, `server_version`, `attrs` (JSON/JSONB), indexed on
+  `occurred_at`, `kind`, `key`, `call_id` and `user_sub`. Hosts that manage the
+  schema with Alembic need a migration creating it (`build_metadata()`
+  includes it). `create_tables=True` creates it on first use. Until it exists,
+  event writes fail and are dropped (logged); calls are unaffected. No change
+  to existing tables.
+
+## [2026.09.28] - 2026-09-28
+
+Keep the tool-call table small: leave out or sample busy tools, and prune old
+rows.
+
+### Added
+- `InstrumentationMiddleware(..., exclude_tools=...)`: tools that are never
+  recorded and never kept for feedback links. The calls themselves are
+  untouched.
+- `InstrumentationMiddleware(..., sample_rates={"tool": 0.01})`: record that
+  fraction of a tool's `ok` calls. **Failures are always recorded**: calls with
+  outcome `error` or `soft_error` are kept whatever the rate. Rates outside
+  (0, 1] raise `ValueError`. Calls sampled out skip the hooks and redaction and
+  are not kept for feedback links. `random=` takes a `() -> float` for tests.
+- Records have a `sample_rate`: the configured rate on sampled-in `ok` rows,
+  None on everything recorded unconditionally (including failures of sampled
+  tools). `SUM(1.0 / COALESCE(sample_rate, 1))` estimates the true call count.
+- `DatabaseSink(..., retention=timedelta(days=30), prune_interval=...,
+  prune_batch=5000)`. With `retention` set, the background writer prunes after
+  an insert at most once per `prune_interval` (one hour by default). A failing
+  prune is logged and never stops the insert.
+- `DatabaseSink.prune(older_than=None) -> int` deletes older rows in batches
+  of `prune_batch`, one transaction each, on SQLite and Postgres. **Calls
+  linked to feedback are never pruned**, and links are never deleted.
+
+### Migration
+- New nullable `sample_rate` column (`Float`) on `{prefix}tool_calls`. Hosts
+  that manage the schema with Alembic need a migration adding it.
+  `create_tables=True` does not alter a table that already exists, so add it by
+  hand there (`ALTER TABLE ffb_tool_calls ADD COLUMN sample_rate FLOAT`). Until
+  the column exists, `DatabaseSink` writes fail and those records are dropped
+  (logged). Hosts still on 2026.09.27.3 or earlier also need the `outcome`
+  column from 2026.09.27.4.
+
+## [2026.09.27.4] - 2026-09-27
+
+Count errors that tools return as data instead of raising.
+
+### Added
+- Records have an `outcome`: `ok`, `soft_error` (the tool returned a result
+  flagged as a failure) or `error` (the tool raised). Soft errors get
+  `error_type="SoftError"` and an `error_message` built from the result, such
+  as `status=failed: disk full`, redacted and truncated to `max_error_chars`.
+- `soft_error_classifier(statuses=..., status_keys=..., flag_keys=...,
+  extra_statuses=...)` builds a classifier that flags dict results where `ok`
+  or `success` is `False`, where `status` or `state` is `error`, `failed` or
+  `failure`, or that the tool marked `isError` without raising.
+  `DEFAULT_RESULT_CLASSIFIER` is `soft_error_classifier()`.
+- `InstrumentationMiddleware(..., result_classifier=...)` takes any
+  `(tool, result) -> str | None`; `None` turns classification off. A
+  classifier that raises is logged and the call is recorded as `ok`.
+- `feedback_context()` rows include `outcome`.
+
+### Changed
+- `ok` is now `outcome == "ok"`, so it is also false for soft errors. Existing
+  `WHERE NOT ok` queries and error rates will rise; filter on
+  `outcome = 'error'` for exceptions only. `CallLink.ok` follows.
+- The package's own feedback tools answer `{"success": False, ...}` on failure,
+  so those calls are now recorded as soft errors.
+
+### Migration
+- New nullable, indexed `outcome` column (`String(16)`) on
+  `{prefix}tool_calls`. Hosts that manage the schema with Alembic need a
+  migration adding it. `create_tables=True` does not alter a table that
+  already exists, so add the column by hand there
+  (`ALTER TABLE ffb_tool_calls ADD COLUMN outcome VARCHAR(16)` plus an index).
+  Until the column exists, `DatabaseSink` writes fail and those records are
+  dropped (logged). Rows from earlier versions keep NULL.
+
+## [2026.09.27.3] - 2026-09-27
+
+Link a feedback item to the tool calls that preceded it.
+
+### Added
+- `InstrumentationMiddleware.capture_recent_calls(ctx, n=20)` returns the
+  calls that led up to now. It matches the same client session first
+  (`session` rule), then fills remaining slots with calls by the same
+  `user_sub` inside `window` (`user_window` rule, 15 minutes by default), and
+  each link records which rule matched.
+- Calls are kept in an in-memory buffer as they happen, so calls still
+  waiting in the sink queue count. With a `DatabaseSink` the lookup falls back
+  to the database, which covers calls from other workers and from before a
+  restart.
+- `link_feedback(ref, links)` stores links against a feedback id of any
+  format (`bug-7Q2X`, `42`) in a new `{prefix}feedback_call_links` table.
+  `build_metadata()` includes it; hosts that manage the schema with Alembic
+  need a new migration.
+- `feedback_context(ref)` returns the linked calls in order with tool,
+  outcome, error type and matching rule, filling in calls not yet written
+  from memory.
+- `add_feedback_tools(..., instrumentation=mw)`: `submit_feedback` links the
+  preceding calls automatically and returns `linked_calls` in its response.
+- `session_key(ctx)` gives a per-client key that stays stable across calls:
+  the HTTP `mcp-session-id` header when present, then one key per process for
+  stdio, then `ctx.session_id`.
+
+### Fixed
+- With `create_tables=True`, the background writer and `link_feedback` could
+  both run `create_all` at once and fail with "table already exists". Table
+  creation is now serialized by a lock.
+
+### Note
+- Clients on MCP protocol 2026-07-28 (Claude Code, FastMCP 4's `Client`)
+  open no HTTP sessions, so their calls link by user only. HTTP servers should
+  configure an `identity_resolver`. Stdio servers link by session with every
+  client.
+
+## [2026.09.27.2] - 2026-09-27
+
+### Fixed
+- `DatabaseSink` stored missing `args`/`result` (every `meta` mode row) as the
+  JSON literal `null`, so `WHERE args IS NULL` matched nothing. They are now
+  SQL `NULL`. No schema change; rows written by 2026.09.27.1 keep JSON `null`
+  and can be backfilled with
+  `UPDATE ffb_tool_calls SET args = NULL WHERE args = 'null'::jsonb` (same for
+  `result`). Reported from production by blender-mcp.
+
+## [2026.09.27.1] - 2026-09-27
+
+Per-call instrumentation for any FastMCP server.
+
+### Added
+- `fastmcp_feedback.instrumentation`: `InstrumentationMiddleware` and
+  `instrument(app)` record every tool call on the server (tool, timing,
+  outcome, original error type, session and request ids, argument and result
+  sizes). Modes `off`, `meta` (default) and `full`, set by argument or
+  `FEEDBACK_INSTRUMENTATION_MODE`; `meta_only_tools` keeps chosen tools at
+  `meta`.
+- Recording never slows or breaks a call: records reach sinks from a
+  background task through a bounded queue and are dropped (and counted) when it
+  is full. Sink and hook errors are logged, never raised; async hooks are cut
+  off after `hook_timeout`.
+- `Redactor`: secrets removed from arguments, results, error text and hook
+  output, by key at any depth and by value pattern (JWT, bearer, `sk-`,
+  GitHub, Slack, AWS, PyPI and `bmcp_` tokens, `password=...` in text).
+- Sinks: `JsonLinesSink` (stderr), `CallbackSink`, `MemorySink`, and
+  `DatabaseSink` on async SQLAlchemy. `DatabaseSink` accepts the host's
+  `AsyncEngine`, writes to a prefixed `ffb_tool_calls` table, never creates
+  tables unless asked, and `build_metadata()` plugs the table into a host's
+  Alembic `env.py`.
+- `identity_resolver` and `enricher` hooks fill `user_sub`, `caller_kind`,
+  `client_id`, `server_version` and free-form `identity`/`extra` fields.
+- `instrumentation` extra: `sqlalchemy[asyncio]` and `aiosqlite`.
+- CI covers FastMCP 3.x as well as 2.12, 2.14 and 4.x.
+
+## [2026.09.27] - 2026-09-27
+
+FastMCP 4 support, and a composition bug that affected every earlier release.
+
+### Fixed
+- `compose_feedback_services()` composed nothing on FastMCP 2.14. It called
+  `import_server()`, which became async in 2.14, without awaiting it, then
+  logged success anyway. On FastMCP 4, where `import_server()` no longer
+  exists, it raised `AttributeError`. It now uses `mount()`, which is
+  synchronous and available on every supported version.
+- The test suite could not start (a pytest-html hook with pytest-html not
+  installed), so it had not run since the package was split out. It runs
+  again: 407 tests.
+
+### Changed
+- Dependency is now `fastmcp>=2.12.2,<5`. Earlier releases had no ceiling,
+  so a fresh install picked up FastMCP 4 untested.
+- `examples/` moved into this repository and ships in the sdist.
+  `create_demo_server()` accepts an optional `database_url`. Examples list
+  and call tools through `fastmcp.Client`, which works on 2.x and 4.x.
+
+### Added
+- CI (Gitea Actions) runs the suite against FastMCP 2.12.2, 2.14.3 and 4.x
+  on every push and weekly, plus a non-blocking job against the newest
+  FastMCP with no ceiling.
+- A composition test using real servers instead of mocks.
+
+### Documentation
+- README rewritten against the code and every Python example executed.
+  Previous docs described things that do not exist: four tools (there are
+  five, including `delete_feedback`), `get_feedback_stats` (it is
+  `get_feedback_statistics`), `InsightsMixin`, an `enable_insights`
+  parameter, feedback types `bug_report`/`feature_request`/`general` (they
+  are `bug`/`feature`/`improvement`/`question`), and a
+  `new -> reviewing -> planned` workflow (it is
+  `open -> in_progress -> resolved -> closed`).
+- The default database is in-memory SQLite (`sqlite:///:memory:`), not
+  `sqlite:///feedback.db` as previously documented. Pass `database_url` to
+  keep feedback across restarts.
+
+## [2026.01.12.1] - 2026-01-12
+
+### Fixed
+- `ImportError` on install: `mixins/base.py` did not re-export the names
+  the other mixin modules import from it.
+
 ## [2026.01.12] - 2026-01-12
 
 ### Added
@@ -20,7 +612,7 @@ and this project adheres to [Calendar Versioning](https://calver.org/) (YYYY.MM.
 - `create_feedback_server()` for server composition
 - Comprehensive test suite (97%+ coverage)
 - Full type hints and Pydantic validation
-- Documentation site at https://fastmcp-feedback.l.supported.systems
+- Documentation site (on a private development address at the time)
 
 ### Technical Details
 - Built on FastMCP 2.12.2+

CONTRIBUTING.md

@@ -1,6 +1,6 @@
 # Contributing to FastMCP Feedback
 
-Thank you for your interest in contributing! This guide will help you get started.
+How to set up, test and submit changes.
 
 ## Development Setup
 
@@ -13,17 +13,16 @@ Thank you for your interest in contributing! This guide will help you get starte
 ### Getting Started
 
 ```bash
-# 1. Fork the repository on git.supported.systems
+# 1. Fork fastmcp-feedback/fastmcp-feedback on git.supported.systems
 # 2. Clone your fork
 git clone git@git.supported.systems:YOUR_USERNAME/fastmcp-feedback.git
 cd fastmcp-feedback
 
-# 3. Create virtual environment and install dependencies
-uv venv
-uv pip install -e ".[dev]"
+# 3. Create .venv from uv.lock with the dev extra
+uv sync --extra dev
 
-# 4. Verify setup
-uv run pytest
+# 4. Verify setup (SQLite only; Postgres cases skip)
+make test
 ```
 
 ### Development Workflow
@@ -35,17 +34,14 @@ git checkout -b feature/your-feature-name
 # Make your changes...
 
 # Run tests
-uv run pytest
+make test
 
 # Run linting
-uv run ruff check .
-uv run ruff format .
-
-# Run type checking (optional but appreciated)
-uv run mypy src/fastmcp_feedback
+make lint
+uv run ruff format --check src/
 
 # Commit with clear message
-git commit -m "feat: Add support for custom validators"
+git commit -m "Count feedback by submitter in get_feedback_statistics"
 
 # Push and create PR
 git push origin feature/your-feature-name
@@ -56,19 +52,21 @@ git push origin feature/your-feature-name
 We use [Ruff](https://docs.astral.sh/ruff/) for linting and formatting:
 
 ```bash
-# Check for issues
-uv run ruff check .
+# Lint src/, examples/ and the test files that are kept ruff-clean
+make lint
 
-# Auto-fix issues
-uv run ruff check --fix .
-
-# Format code
-uv run ruff format .
+# Format what you changed
+uv run ruff format src/ path/to/your_test.py
 ```
 
+Many of the older test files predate the ruff configuration and do not pass
+it, so `ruff check .` over the whole repository reports errors that are not
+yours. `src/` must stay clean, and new test files should be added to the
+`lint` target in the Makefile.
+
 ### Style Guidelines
 
-- **Line length**: 88 characters (Black default)
+- **Line length**: 88 characters
 - **Imports**: Sorted with isort (via Ruff)
 - **Type hints**: Required for public APIs
 - **Docstrings**: Google style for public functions
@@ -78,11 +76,11 @@ uv run ruff format .
 ### Running Tests
 
 ```bash
-# Run all tests
+# Run all tests (coverage is on by default, see pyproject.toml)
 uv run pytest
 
-# Run with coverage
-uv run pytest --cov
+# Without the coverage report, as the Makefile does
+uv run pytest -q --no-cov
 
 # Run specific test file
 uv run pytest tests/unit/test_tools.py
@@ -90,13 +88,57 @@ uv run pytest tests/unit/test_tools.py
 # Run specific test
 uv run pytest -k "test_submit_feedback"
 
-# Run only unit tests
-uv run pytest -m unit
-
-# Run only integration tests
-uv run pytest -m integration
+# Run one directory
+uv run pytest tests/integration
 ```
 
+### Running the tests against Postgres
+
+The `DatabaseSink` tests run on SQLite by default. Each one also has a
+`[postgres]` variant that runs against a real Postgres 16 with pgvector
+when `FFB_TEST_DATABASE_URL` is set, and skips otherwise. The repo ships a
+compose stack for it (Docker required):
+
+```bash
+make pg-up      # start ffb-postgres and wait until healthy (creates .env on first run)
+make test-pg    # whole suite, Postgres cases enabled
+make test       # whole suite, SQLite only
+make test-all   # both
+make pg-down    # stop it; the data volume is kept (pg-reset deletes it)
+```
+
+The server listens on `127.0.0.1` only, on `FFB_PG_PORT` from `.env`
+(55447 by default; change it if that port is taken). `make pg-psql` opens a
+shell on it. Every Postgres test gets its own freshly created database with
+the `vector` extension, dropped when the test ends, so tests never see each
+other's rows. To write a test that runs on both backends, take the `db_url`
+fixture from `tests/conftest.py`: `db_url("name")` returns an async URL for
+an empty database, the same one for the same name within a test. The
+feedback tools use a synchronous engine, so convert that URL's driver
+(`sqlite`, `postgresql+psycopg2`) as the `feedback_db` fixture in
+`tests/unit/test_consistency.py` does; psycopg2 comes with the dev extra.
+
+To point the suite at another server, set the variable yourself; the user
+needs permission to create and drop databases:
+
+```bash
+FFB_TEST_DATABASE_URL=postgresql+asyncpg://user:pass@host:5432/postgres uv run pytest -m postgres
+```
+
+### Embedding tests against a real endpoint
+
+`tests/unit/test_embeddings.py` uses a deterministic fake embedder. One test
+embeds through a real OpenAI-compatible endpoint when you point it at one, and
+skips otherwise:
+
+```bash
+FFB_TEST_EMBED_URL=https://api.example.com/v1 FFB_TEST_EMBED_KEY=... \
+  uv run pytest tests/unit/test_embeddings.py -k live
+```
+
+`FFB_TEST_EMBED_MODEL` (default `mxbai-embed-large`) and `FFB_TEST_EMBED_DIM`
+(default 1024) pick the model.
+
 ### Writing Tests
 
 - Place unit tests in `tests/unit/`
@@ -104,44 +146,60 @@ uv run pytest -m integration
 - Use descriptive test names: `test_submit_feedback_with_invalid_type_raises_error`
 - Use fixtures from `tests/conftest.py`
 
-Example test:
+Tests are async without a marker (`asyncio_mode = "auto"`). Call tools the
+way a client does, through `fastmcp.Client`. `submit_feedback` takes one
+argument, `request`, holding the fields of `SubmitFeedbackRequest`; `type`
+is one of `bug`, `feature`, `improvement` or `question`. Tools report
+failure in the result (`success: False` and an `error`) rather than raising.
 
 ```python
-import pytest
+from fastmcp import Client, FastMCP
+
 from fastmcp_feedback import add_feedback_tools
 
-@pytest.mark.unit
-async def test_submit_feedback_creates_record(app_with_feedback, db_session):
-    """Submitting feedback should create a database record."""
-    result = await app_with_feedback.call_tool(
-        "submit_feedback",
-        type="bug_report",
-        title="Test Bug",
-        description="Description"
-    )
 
-    assert result["status"] == "success"
-    assert result["id"] is not None
+async def test_submit_feedback_creates_record(tmp_path):
+    app = FastMCP("test")
+    add_feedback_tools(app, database_url=f"sqlite:///{tmp_path}/feedback.db")
+
+    async with Client(app) as client:
+        result = await client.call_tool(
+            "submit_feedback",
+            {
+                "request": {
+                    "type": "bug",
+                    "title": "Export fails",
+                    "description": "Exporting a scene with no objects raises",
+                    "submitter": "test",
+                }
+            },
+        )
+        listed = await client.call_tool("list_feedback", {})
+        stats = await client.call_tool("get_feedback_statistics", {})
+
+    assert result.structured_content["success"] is True
+    [item] = listed.structured_content["feedback"]
+    assert item["id"] == result.structured_content["feedback_id"]
+    assert (item["type"], item["status"]) == ("bug", "open")
+    assert stats.structured_content["by_type"] == {"bug": 1}
 ```
 
 ## Pull Request Guidelines
 
 ### Before Submitting
 
-1. **Tests pass**: `uv run pytest`
-2. **Linting passes**: `uv run ruff check .`
+1. **Tests pass**: `make test`, and `make test-pg` when you touched database code
+2. **Linting passes**: `make lint`
 3. **New features have tests**
 4. **Documentation updated** (if applicable)
 
 ### PR Title Format
 
-Use [Conventional Commits](https://www.conventionalcommits.org/):
+Say what changes, in the imperative, as the commit log does:
 
-- `feat: Add custom validation support`
-- `fix: Handle empty feedback list correctly`
-- `docs: Update installation instructions`
-- `test: Add edge case tests for insights`
-- `refactor: Simplify database connection logic`
+- `Key feedback statistics by enum value`
+- `Resolve caller identity before the tool runs`
+- `Import instrumentation without the database extras`
 
 ### PR Description Template
 
@@ -171,16 +229,20 @@ fastmcp-feedback/
 │   ├── models.py         # Pydantic models and SQLAlchemy ORM
 │   ├── database.py       # Database connection management
 │   ├── feedback.py       # Standalone server factory
-│   ├── insights.py       # Privacy-compliant analytics
-│   └── mixins/           # Modular tool mixins
-│       ├── base.py
-│       ├── submission.py
-│       ├── retrieval.py
-│       └── management.py
+│   ├── insights.py       # In-process usage metrics
+│   ├── mixins/           # The feedback tools, grouped
+│   │   ├── base.py       # BaseFeedbackMixin
+│   │   ├── submission.py
+│   │   ├── retrieval.py
+│   │   └── management.py
+│   └── instrumentation/  # Middleware, sinks, events, embeddings, backfill
 ├── tests/
-│   ├── conftest.py       # Shared fixtures
+│   ├── conftest.py       # Shared fixtures, including db_backend and db_url
+│   ├── _databases.py     # Per-test Postgres databases
 │   ├── unit/             # Unit tests
 │   └── integration/      # Integration tests
+├── docker-compose.yml    # Postgres + pgvector for make test-pg
+├── Makefile
 ├── pyproject.toml        # Package configuration
 ├── README.md
 ├── CONTRIBUTING.md       # This file
@@ -192,28 +254,56 @@ fastmcp-feedback/
 
 ### Adding a New Mixin
 
-1. Create `src/fastmcp_feedback/mixins/your_mixin.py`
-2. Inherit from `BaseMixin`
-3. Implement `register_tools(app, prefix="")`
-4. Export from `src/fastmcp_feedback/mixins/__init__.py`
-5. Add to main `__init__.py` exports
-6. Write tests in `tests/unit/test_your_mixin.py`
-7. Update documentation
+A mixin subclasses `BaseFeedbackMixin`, which holds the `FeedbackDatabase`
+(`self.database`) and the `FeedbackInsights` (`self.insights`). Its tools are
+methods decorated with `mcp_tool` from `fastmcp.contrib.mcp_mixin`;
+`register_tools(app, prefix=...)`, inherited from FastMCP's `MCPMixin`, adds
+them to a server.
+
+```python
+from fastmcp import FastMCP
+
+from fastmcp_feedback import FeedbackDatabase
+from fastmcp_feedback.mixins.base import BaseFeedbackMixin, Feedback, mcp_tool
+
+
+class CountMixin(BaseFeedbackMixin):
+    @mcp_tool(description="Count feedback items")
+    async def count_feedback(self) -> dict:
+        async with self.database.session() as session:
+            return {"count": session.query(Feedback).count()}
+
+
+app = FastMCP("demo")
+CountMixin(FeedbackDatabase("sqlite:///:memory:")).register_tools(app, prefix="admin")
+# The tool is registered as admin_count_feedback.
+```
+
+Then:
+
+1. Put it in `src/fastmcp_feedback/mixins/your_mixin.py`
+2. Export it from `src/fastmcp_feedback/mixins/__init__.py` and the package `__init__.py`
+3. Write tests in `tests/unit/`, calling the tool through `fastmcp.Client`
+4. Document it in README.md and on the docs site
 
 ### Adding a New Tool
 
-1. Add to appropriate mixin or create new one
-2. Use `@app.tool()` decorator with clear description
-3. Add Pydantic models for request/response if complex
-4. Write unit tests
-5. Add integration test
-6. Document in README
+1. Add a method to the mixin it belongs to, decorated with `mcp_tool` and a
+   description written for the model that will call it
+2. Return a dict; report failures as `{"success": False, "error": ...}`
+   instead of raising
+3. Return enum fields as their values (`bug`, `in_progress`), as
+   `feedback_to_dict` does; the database stores the names
+4. Use a Pydantic model for structured input
+5. Test it on both backends where it touches the database (`make test-pg`)
 
 ## Versioning
 
 We use **calendar versioning** (CalVer): `YYYY.MM.DD`
 
-Version bumps happen automatically on release. Contributors don't need to update version numbers.
+A release bumps the version in `pyproject.toml` and
+`src/fastmcp_feedback/__init__.py` and adds a CHANGELOG entry. Contributors
+don't need to update version numbers.
 
 ## Getting Help
 

Makefile

@@ -0,0 +1,65 @@
+# Dev/test helpers. The Postgres stack exists only so the test suite can run
+# against a real server; see CONTRIBUTING.md.
+
+COMPOSE ?= docker compose
+PYTEST ?= uv run --no-sync pytest
+PYTEST_ARGS ?= -q --no-cov
+
+# FFB_TEST_DATABASE_URL and friends come from .env when it exists. A value
+# already in the environment (CI points it at a service container) wins.
+ENV_TEST_DATABASE_URL := $(FFB_TEST_DATABASE_URL)
+-include .env
+ifneq ($(ENV_TEST_DATABASE_URL),)
+FFB_TEST_DATABASE_URL := $(ENV_TEST_DATABASE_URL)
+endif
+
+.PHONY: help pg-up pg-down pg-logs pg-psql pg-reset test test-pg test-all lint
+
+help:
+	@echo "pg-up     start Postgres + pgvector and wait until healthy"
+	@echo "pg-down   stop it (the data volume is kept)"
+	@echo "pg-reset  stop it and delete the data volume"
+	@echo "pg-logs   follow its logs"
+	@echo "pg-psql   psql into the test database"
+	@echo "test      test suite on SQLite only (Postgres cases skip)"
+	@echo "test-pg   test suite with the Postgres cases enabled (needs pg-up)"
+	@echo "test-all  both"
+	@echo "lint      ruff"
+
+# First run: copy the example and give it a random password.
+.env:
+	@pw=$$(openssl rand -hex 16); sed "s/change-me/$$pw/g" .env.example > .env
+	@echo "wrote .env from .env.example"
+
+pg-up: .env
+	$(COMPOSE) up -d --wait ffb-postgres
+	$(COMPOSE) logs --tail=20 ffb-postgres
+
+pg-down:
+	$(COMPOSE) down
+
+pg-reset:
+	$(COMPOSE) down -v
+
+pg-logs:
+	$(COMPOSE) logs -f ffb-postgres
+
+pg-psql:
+	$(COMPOSE) exec ffb-postgres psql -U "$(FFB_PG_USER)" -d "$(FFB_PG_DB)"
+
+test:
+	env -u FFB_TEST_DATABASE_URL $(PYTEST) $(PYTEST_ARGS)
+
+test-pg: .env
+	@test -n "$(FFB_TEST_DATABASE_URL)" || { echo "FFB_TEST_DATABASE_URL is not set (environment or .env)"; exit 1; }
+	@echo "$(PYTEST) $(PYTEST_ARGS)  (Postgres cases enabled)"
+	@FFB_TEST_DATABASE_URL="$(FFB_TEST_DATABASE_URL)" $(PYTEST) $(PYTEST_ARGS)
+
+test-all: test test-pg
+
+lint:
+	uv run --no-sync ruff check src/ examples/ tests/_compat.py tests/_databases.py \
+		tests/unit/test_test_databases.py tests/unit/test_instrumentation.py \
+		tests/unit/test_embeddings.py tests/unit/test_backfill.py \
+		tests/unit/test_consistency.py tests/unit/test_late_identity.py \
+		tests/unit/test_payload_cap.py tests/unit/test_classifier_paths.py

docker-compose.yml

@@ -0,0 +1,31 @@
+# Postgres + pgvector for running the test suite against a real server.
+# Test-only: nothing here serves HTTP, so there is no caddy network.
+# The port is published on 127.0.0.1 only, for pytest running on the host.
+
+services:
+  ffb-postgres:
+    image: ${FFB_PG_IMAGE:-pgvector/pgvector:pg16}
+    restart: unless-stopped
+    environment:
+      POSTGRES_USER: ${FFB_PG_USER}
+      POSTGRES_PASSWORD: ${FFB_PG_PASSWORD}
+      POSTGRES_DB: ${FFB_PG_DB}
+    ports:
+      - "127.0.0.1:${FFB_PG_PORT:-55447}:5432"
+    volumes:
+      - ffb-postgres-data:/var/lib/postgresql/data
+      - ./docker/postgres-init:/docker-entrypoint-initdb.d:ro
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U \"$${POSTGRES_USER}\" -d \"$${POSTGRES_DB}\""]
+      interval: 2s
+      timeout: 3s
+      retries: 30
+      start_period: 5s
+    networks:
+      - internal
+
+volumes:
+  ffb-postgres-data:
+
+networks:
+  internal:

docker/pgvector-alpine/Dockerfile

@@ -0,0 +1,13 @@
+# Postgres on Alpine with pgvector built in. Keeps the musl C library, so an
+# existing data directory's collation and text indexes are unaffected.
+# with_llvm=no: the base image's Postgres was built with a specific clang for
+# JIT bitcode that Alpine may no longer ship; pgvector itself builds with gcc.
+ARG PG_MAJOR=16
+FROM postgres:${PG_MAJOR}-alpine
+ARG PGVECTOR_VERSION=v0.8.6
+RUN apk add --no-cache --virtual .build-deps git build-base \
+ && git clone --depth 1 --branch ${PGVECTOR_VERSION} https://github.com/pgvector/pgvector.git /tmp/pgvector \
+ && make -C /tmp/pgvector OPTFLAGS="" with_llvm=no \
+ && make -C /tmp/pgvector install with_llvm=no \
+ && rm -rf /tmp/pgvector \
+ && apk del .build-deps

docker/pgvector-alpine/README.md

@@ -0,0 +1,28 @@
+# Postgres on Alpine with pgvector
+
+For stacks that already run `postgres:NN-alpine` and want the `vector`
+extension for fastmcp-feedback embeddings.
+
+Why not switch to the `pgvector/pgvector` image: it's Debian (glibc), and the
+Alpine images use musl. The two C libraries sort text differently under
+locales such as `en_US.utf8`, so reusing an Alpine data directory under a
+Debian image changes the order of every text index. The indexes need a full
+`REINDEX` or they silently return wrong results. Building pgvector into the
+same Alpine image keeps the data directory's collation unchanged.
+
+```bash
+docker build --build-arg PG_MAJOR=16 -t postgres-pgvector:16-alpine .
+docker build --build-arg PG_MAJOR=17 -t postgres-pgvector:17-alpine .
+```
+
+Then point the stack's Postgres service at the new image (same major version
+as the existing data directory) and run `CREATE EXTENSION IF NOT EXISTS
+vector;` once, or let a migration do it.
+
+Tested 2026-09-30 with pgvector v0.8.6 on postgres:16-alpine and
+postgres:17-alpine: the extension loads, and an HNSW `vector_cosine_ops`
+index is used for `ORDER BY embedding <=> ...` queries.
+
+`with_llvm=no` skips the LLVM bitcode used for JIT inlining. The base images'
+Postgres was built with a clang version Alpine no longer ships, so the bitcode
+step fails; pgvector itself still builds with gcc and works normally.

docker/postgres-init/01-vector.sql

@@ -0,0 +1,6 @@
+-- Runs once, on first start with an empty volume.
+-- The test fixtures create a fresh database per test from template1, so the
+-- extension goes there too; every database created afterwards inherits it.
+CREATE EXTENSION IF NOT EXISTS vector;
+\connect template1
+CREATE EXTENSION IF NOT EXISTS vector;

examples/README.md

@@ -0,0 +1,318 @@
+# FastMCP Feedback Examples
+
+This directory contains comprehensive examples demonstrating all features of the FastMCP Feedback system.
+
+## 🚀 Demo Server
+
+### `demo_server.py`
+**Complete demonstration server showcasing all features**
+
+**Features Demonstrated:**
+- ✅ Complete feedback collection workflow
+- ✅ Privacy-compliant analytics (GDPR-ready) 
+- ✅ Multi-database support (SQLite, PostgreSQL, MySQL)
+- ✅ Thread-safe operations with 97% test coverage
+- ✅ Server composition patterns
+- ✅ Performance monitoring and health checks
+- ✅ Sample data for testing
+
+**Available Tools:**
+- `submit_feedback` - Submit bug reports, feature requests, improvements, questions
+- `list_feedback` - Query and filter feedback with pagination
+- `get_feedback_statistics` - Analytics and aggregate metrics
+- `update_feedback_status` - Change status (open → in_progress → resolved)
+- `delete_feedback` - Remove feedback items
+- `get_system_info` - Version and dependency information
+- `setup_sample_data` - Populate with realistic demo data
+
+**Usage:**
+
+```bash
+# Run the demo server
+python examples/demo_server.py
+
+# Or with uv
+uv run examples/demo_server.py
+```
+
+**Claude Desktop MCP Configuration:**
+```json
+{
+  "mcpServers": {
+    "fastmcp-feedback-demo": {
+      "command": "uv",
+      "args": ["run", "examples/demo_server.py"],
+      "env": {
+        "LOG_LEVEL": "INFO"
+      }
+    }
+  }
+}
+```
+
+## 🏗️ Architecture Examples
+
+### `simple_integration.py`
+**Minimal integration example - 3 lines of code**
+
+```python
+from fastmcp import FastMCP
+from fastmcp_feedback import add_feedback_tools
+
+app = FastMCP("My App")
+add_feedback_tools(app, database_url="sqlite:///feedback.db")
+```
+
+### `advanced_configuration.py` 
+**Production-ready configuration with all features**
+
+```python
+from fastmcp_feedback import (
+    add_feedback_tools,
+    FeedbackInsights,
+    FeedbackDatabase
+)
+
+# Configure privacy-compliant analytics
+insights = FeedbackInsights(
+    enabled=True,
+    retention_days=90,
+    privacy_compliant=True
+)
+
+# Setup database with connection pooling
+database = FeedbackDatabase(
+    "postgresql://user:pass@localhost/feedback",
+    pool_size=20,
+    max_overflow=10
+)
+
+# Add tools with custom prefix
+add_feedback_tools(
+    app,
+    database=database,
+    insights=insights,
+    prefix="support_"
+)
+```
+
+### `server_composition.py`
+**Multi-server composition patterns**
+
+```python
+from fastmcp_feedback.feedback import (
+    create_submission_server,
+    create_management_server,
+    create_analytics_server
+)
+
+# Create specialized servers
+public_server = create_submission_server("Public Portal")
+admin_server = create_management_server("Admin Panel") 
+analytics = create_analytics_server("Dashboard")
+
+# Compose into main application
+main_app = FastMCP("Main Application")
+await main_app.import_server(public_server, prefix="public")
+await main_app.import_server(admin_server, prefix="admin")
+await main_app.import_server(analytics, prefix="stats")
+```
+
+## 🎯 Usage Patterns
+
+### Basic Feedback Workflow
+
+1. **Submit Feedback:**
+   ```python
+   # Submit a bug report
+   result = await submit_feedback({
+       "request": {
+           "type": "bug",
+           "title": "Login page not responsive on mobile",
+           "description": "The login form overflows on screens < 768px width",
+           "submitter": "user_123",
+           "contact_info": "user@example.com"
+       }
+   })
+   ```
+
+2. **List and Filter:**
+   ```python
+   # Get all open bug reports
+   bugs = await list_feedback({
+       "type_filter": "bug",
+       "status_filter": "open", 
+       "limit": 20
+   })
+   ```
+
+3. **Update Status:**
+   ```python
+   # Mark as in progress
+   await update_feedback_status({
+       "feedback_id": "123",
+       "new_status": "in_progress",
+       "note": "Engineering team investigating"
+   })
+   ```
+
+4. **Get Analytics:**
+   ```python
+   # View statistics
+   stats = await get_feedback_statistics()
+   # Returns: {"total_count": 45, "by_type": {"BUG": 12, "FEATURE": 20}, ...}
+   ```
+
+## 🔒 Privacy & Security Examples
+
+### Privacy-Compliant Configuration
+```python
+insights = FeedbackInsights(
+    enabled=True,                    # Enable analytics
+    retention_days=90,               # Auto-cleanup after 90 days
+    privacy_compliant=True,          # Enforce GDPR compliance
+    anonymize_identifiers=True,      # Hash user identifiers
+    exclude_contact_info=True        # Don't store in metrics
+)
+```
+
+### Security Features
+```python
+# Input validation with Pydantic
+from fastmcp_feedback.models import SubmitFeedbackRequest
+
+# SQL injection prevention via SQLAlchemy ORM
+# Rate limiting support (extend mixins)
+# Authentication ready (add middleware)
+```
+
+## 📊 Performance Examples
+
+### Connection Pooling
+```python
+database = FeedbackDatabase(
+    "postgresql://localhost/feedback",
+    pool_size=20,           # Base connections
+    max_overflow=10,        # Burst capacity
+    pool_timeout=30,        # Connection timeout
+    pool_recycle=3600       # Refresh every hour
+)
+```
+
+### Bulk Operations
+```python
+# Bulk status updates
+result = await bulk_update_status(
+    feedback_ids=["1", "2", "3", "4", "5"],
+    new_status="resolved"
+)
+```
+
+### Performance Monitoring
+```python
+# Built-in health checks
+health = await database.health_check()
+if not health:
+    # Trigger alerts
+    pass
+
+# Performance metrics
+stats = await get_database_stats()
+# Returns connection pool status, query times, etc.
+```
+
+## 🧪 Testing Examples
+
+### Unit Testing with FastMCP Feedback
+```python
+import pytest
+from fastmcp_feedback import FeedbackDatabase
+
+@pytest.mark.asyncio
+async def test_feedback_submission():
+    # Use in-memory database for testing
+    db = FeedbackDatabase("sqlite:///:memory:")
+    await db.initialize()
+    
+    # Test feedback submission
+    # ... test code here
+    
+    await db.close()
+```
+
+### Integration Testing
+```python
+# Test complete workflows
+async def test_complete_feedback_lifecycle():
+    # Submit → List → Update → Verify → Analytics
+    pass
+```
+
+## 🚀 Production Deployment Examples
+
+### Docker Configuration
+```dockerfile
+FROM python:3.11-slim
+
+WORKDIR /app
+COPY pyproject.toml .
+RUN pip install -e .
+
+COPY src/ src/
+COPY examples/ examples/
+
+# Health check
+HEALTHCHECK --interval=30s --timeout=10s \
+  CMD python -c "import asyncio; from examples.health_check import check; asyncio.run(check())"
+
+CMD ["python", "examples/demo_server.py"]
+```
+
+### Environment Configuration
+```bash
+# Database
+DATABASE_URL=postgresql://user:pass@db:5432/feedback
+
+# Analytics
+INSIGHTS_ENABLED=true
+INSIGHTS_RETENTION_DAYS=90
+
+# Performance
+CONNECTION_POOL_SIZE=20
+MAX_OVERFLOW=10
+
+# Security
+RATE_LIMIT_REQUESTS=100
+RATE_LIMIT_WINDOW=3600
+```
+
+## 📚 Documentation
+
+Each example includes:
+- **Comprehensive comments** explaining every feature
+- **Error handling** patterns
+- **Performance considerations**
+- **Security best practices**  
+- **Testing approaches**
+- **Production deployment guidance**
+
+## 🎯 Getting Started
+
+1. **Start with the demo server** - `python examples/demo_server.py`
+2. **Connect to Claude Desktop** using the MCP configuration above
+3. **Try the tools** - submit feedback, query results, update status
+4. **Explore the code** - see how each feature is implemented
+5. **Customize for your needs** - adapt patterns to your use case
+
+## 🤝 Contributing Examples
+
+We welcome additional examples! Please:
+- Include comprehensive comments
+- Add error handling
+- Provide usage instructions  
+- Update this README
+- Add tests if applicable
+
+---
+
+**These examples demonstrate production-ready FastMCP Feedback integration with 97% test coverage and enterprise-grade reliability.**

examples/demo_server.md

@@ -0,0 +1,247 @@
+# FastMCP Feedback Demo Server
+
+**File:** `demo_server.py`  
+**Purpose:** Comprehensive demonstration of all FastMCP Feedback features  
+**Lines:** 396 lines of production-ready code  
+**Test Coverage:** Validated through 396+ comprehensive tests  
+
+## 🎯 Overview
+
+The demo server is a complete, production-ready FastMCP server that showcases every feature of the FastMCP Feedback system. It's designed to demonstrate real-world usage patterns and serve as a reference implementation for developers.
+
+## ✨ Features Demonstrated
+
+### Core Feedback System
+- **Complete CRUD Operations** - Submit, retrieve, update, delete feedback
+- **Type Support** - Bug reports, feature requests, improvements, questions
+- **Status Management** - Open → In Progress → Resolved → Closed workflow
+- **Rich Metadata** - Timestamps, submitter info, contact details
+
+### Advanced Capabilities
+- **Privacy-Compliant Analytics** - GDPR-ready insights collection
+- **Multi-Database Support** - SQLite for development, PostgreSQL for production
+- **Thread-Safe Operations** - Concurrent request handling
+- **Performance Monitoring** - Health checks and dependency validation
+- **Server Composition** - Multiple specialized server types
+
+### Data Integrity
+- **Input Validation** - Pydantic models with comprehensive validation
+- **Unicode Support** - Emojis, special characters, international text
+- **Timezone Handling** - UTC-aware timestamp management
+- **Whitespace Normalization** - Consistent data cleaning
+
+## 🛠️ Available Tools (7 Total)
+
+| Tool | Description | Use Case |
+|------|-------------|----------|
+| `submit_feedback` | Submit new feedback items | Users reporting bugs/requesting features |
+| `list_feedback` | Query and filter feedback | Viewing feedback with pagination/filtering |
+| `get_feedback_statistics` | Analytics and metrics | Dashboard data and reporting |
+| `update_feedback_status` | Change feedback status | Admin workflow management |
+| `delete_feedback` | Remove feedback items | Content moderation |
+| `get_system_info` | Version/dependency info | System diagnostics |
+| `setup_sample_data` | Populate demo data | Testing and demonstration |
+
+## 📊 Sample Data
+
+The demo server includes realistic sample data:
+
+```python
+sample_feedback = [
+    {
+        "type": "bug",
+        "title": "Memory leak in analytics processing",
+        "description": "Analytics worker consumes increasing memory over time...",
+        "submitter": "alice@example.com",
+        "contact_info": "alice@engineering.example.com"
+    },
+    {
+        "type": "feature", 
+        "title": "Add export functionality for feedback data",
+        "description": "Users need ability to export feedback data as CSV or JSON...",
+        "submitter": "product_manager",
+        "contact_info": "pm@example.com"
+    }
+    # ... 3 more realistic examples
+]
+```
+
+## 🚀 Usage
+
+### Direct Execution
+```bash
+# Run with Python
+python examples/demo_server.py
+
+# Run with uv (recommended)
+uv run examples/demo_server.py
+```
+
+### Claude Desktop Integration
+```json
+{
+  "mcpServers": {
+    "fastmcp-feedback-demo": {
+      "command": "uv",
+      "args": ["run", "examples/demo_server.py"],
+      "env": {
+        "DATABASE_URL": "sqlite:///feedback_demo.db",
+        "LOG_LEVEL": "INFO"
+      }
+    }
+  }
+}
+```
+
+### Docker Deployment
+```dockerfile
+FROM python:3.11-slim
+COPY . /app
+WORKDIR /app
+RUN pip install uv && uv sync
+CMD ["uv", "run", "examples/demo_server.py"]
+```
+
+## 🔧 Configuration Options
+
+### Environment Variables
+- `DATABASE_URL` - Database connection string (default: temporary SQLite)
+- `LOG_LEVEL` - Logging verbosity (DEBUG, INFO, WARNING, ERROR)
+- `INSIGHTS_ENABLED` - Enable/disable analytics collection
+- `RETENTION_DAYS` - Analytics data retention period
+
+### Database Support
+- **SQLite** - `sqlite:///path/to/database.db` (development)
+- **PostgreSQL** - `postgresql://user:pass@host:port/db` (production)
+- **In-Memory** - `sqlite:///:memory:` (testing)
+
+## 📈 Performance Characteristics
+
+### Throughput
+- **Concurrent Requests** - Handles 100+ concurrent submissions
+- **Database Performance** - Optimized queries with indexing
+- **Memory Usage** - Efficient async/await patterns
+
+### Scalability
+- **Horizontal Scaling** - Stateless design supports load balancing
+- **Database Scaling** - Connection pooling and query optimization
+- **Analytics Scaling** - Configurable retention and aggregation
+
+## 🧪 Testing Integration
+
+The demo server is thoroughly tested through:
+
+### Unit Tests
+- Tool registration and configuration
+- Sample data generation
+- Error handling scenarios
+
+### Integration Tests
+- End-to-end workflow validation
+- Database operations
+- Server composition patterns
+
+### Performance Tests
+- High-volume operations
+- Concurrent request handling
+- Memory usage monitoring
+
+## 🎓 Learning Examples
+
+### Basic Feedback Submission
+```python
+# Submit a bug report
+result = await submit_feedback({
+    "type": "bug",
+    "title": "Application crashes on startup",
+    "description": "Detailed error description...",
+    "submitter": "developer@company.com"
+})
+```
+
+### Advanced Filtering
+```python
+# Get all open bug reports from last week
+feedback = await list_feedback({
+    "type_filter": "bug",
+    "status_filter": "open", 
+    "limit": 50
+})
+```
+
+### Analytics Query
+```python
+# Get comprehensive statistics
+stats = await get_feedback_statistics()
+# Returns: total_count, by_type, by_status, recent_count
+```
+
+## 🔍 Architecture Insights
+
+### Server Composition Pattern
+```python
+# The demo server demonstrates server composition:
+main_server = FastMCP("Demo Server")
+feedback_server = create_feedback_server("Feedback Service")
+main_server.import_server(feedback_server, prefix="feedback_")
+```
+
+### Database Abstraction
+```python
+# Flexible database backend:
+database = FeedbackDatabase(database_url)
+await database.initialize()  # Auto-creates tables
+```
+
+### Analytics Integration
+```python
+# Privacy-compliant analytics:
+insights = FeedbackInsights(enabled=True, retention_days=90)
+insights.record_metric("feedback_submitted", metadata)
+```
+
+## 📚 Related Documentation
+
+- **[Simple Integration](simple_integration.md)** - Minimal 3-line integration
+- **[Production Server](mcp_server.md)** - Environment-configured deployment
+- **[Testing Guide](../tests/README.md)** - Comprehensive test documentation
+- **[Architecture Overview](../docs/architecture.md)** - System design details
+
+## 🤝 Contributing
+
+When modifying the demo server:
+
+1. **Maintain Compatibility** - Ensure all existing tools continue working
+2. **Update Documentation** - Keep this file synchronized with code changes
+3. **Add Tests** - Include test coverage for new features
+4. **Version Compatibility** - Support multiple FastMCP versions where possible
+
+## 🐛 Troubleshooting
+
+### Common Issues
+
+**Database Errors**
+```bash
+# Check database permissions
+ls -la feedback_demo.db
+# Reset database
+rm feedback_demo.db && python examples/demo_server.py
+```
+
+**Import Errors**
+```bash
+# Ensure development installation
+uv sync
+# Check Python path
+python -c "import fastmcp_feedback; print('OK')"
+```
+
+**Performance Issues**
+```bash
+# Enable debug logging
+LOG_LEVEL=DEBUG python examples/demo_server.py
+# Monitor memory usage
+ps aux | grep demo_server
+```
+
+This demo server represents the gold standard for FastMCP Feedback integration, demonstrating every feature with production-ready code patterns and comprehensive error handling.

examples/demo_server.py

@@ -0,0 +1,402 @@
+#!/usr/bin/env python3
+"""
+FastMCP Feedback Demo Server
+
+A comprehensive demonstration server that showcases all features of the
+FastMCP Feedback system including:
+- Complete feedback collection workflow
+- Privacy-compliant analytics
+- Multi-database support
+- Performance monitoring
+- Server composition patterns
+
+Usage:
+    # Run the demo server
+    python examples/demo_server.py
+
+    # Or use uv
+    uv run examples/demo_server.py
+
+    # Connect from Claude Desktop with this MCP server configuration:
+    # {
+    #   "feedback-demo": {
+    #     "command": "uv",
+    #     "args": ["run", "examples/demo_server.py"]
+    #   }
+    # }
+"""
+
+import asyncio
+import logging
+import sys
+import tempfile
+from datetime import UTC, datetime
+from pathlib import Path
+
+# Add the src directory to the path for development
+sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
+
+from fastmcp import Client, FastMCP
+
+from fastmcp_feedback import (
+    FeedbackDatabase,
+    FeedbackInsights,
+    add_feedback_tools,
+    check_dependencies,
+    get_version_info,
+)
+from fastmcp_feedback.feedback import (
+    create_analytics_server,
+    create_management_server,
+    create_submission_server,
+)
+
+# Configure logging
+logging.basicConfig(
+    level=logging.INFO,
+    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
+    handlers=[logging.StreamHandler(), logging.FileHandler("feedback_demo.log")],
+)
+
+logger = logging.getLogger(__name__)
+
+
+def create_temp_database() -> str:
+    """Create a temporary SQLite database for the demo."""
+    temp_dir = tempfile.mkdtemp(prefix="fastmcp_feedback_demo_")
+    db_path = Path(temp_dir) / "demo_feedback.db"
+    return f"sqlite:///{db_path}"
+
+
+async def setup_demo_data(database: FeedbackDatabase) -> None:
+    """Populate the database with sample feedback for demonstration."""
+    logger.info("Setting up demo data...")
+
+    sample_feedback = [
+        {
+            "type": "bug",
+            "title": "Memory leak in analytics processing",
+            "description": "Analytics worker consumes increasing memory over time, eventually causing OOM errors.",
+            "submitter": "alice@example.com",
+            "contact_info": "alice@engineering.example.com",
+        },
+        {
+            "type": "feature",
+            "title": "Add export functionality for feedback data",
+            "description": "Users need ability to export feedback data as CSV or JSON for external analysis.",
+            "submitter": "product_manager",
+            "contact_info": "pm@example.com",
+        },
+        {
+            "type": "improvement",
+            "title": "Optimize database query performance",
+            "description": "List feedback queries are slow with large datasets. Need pagination and indexing improvements.",
+            "submitter": "performance_team",
+        },
+        {
+            "type": "question",
+            "title": "Best practices for rate limiting?",
+            "description": "What are recommended rate limits for feedback submission to prevent abuse?",
+            "submitter": "security_team",
+            "contact_info": "security@example.com",
+        },
+        {
+            "type": "bug",
+            "title": "Unicode handling in feedback titles",
+            "description": "Emojis and special characters cause encoding errors in feedback titles. 🐛",
+            "submitter": "qa_engineer",
+        },
+    ]
+
+    try:
+        await database.initialize()
+
+        # Import the model here to avoid circular imports
+        from fastmcp_feedback.models import Feedback, FeedbackStatus, FeedbackType
+
+        async with database.session() as session:
+            for item in sample_feedback:
+                feedback = Feedback(
+                    type=FeedbackType(item["type"]),
+                    status=FeedbackStatus.OPEN,
+                    title=item["title"],
+                    description=item["description"],
+                    submitter=item["submitter"],
+                    contact_info=item.get("contact_info"),
+                    created_at=datetime.now(UTC),
+                    updated_at=datetime.now(UTC),
+                )
+                session.add(feedback)
+
+            session.commit()
+            logger.info(f"Added {len(sample_feedback)} sample feedback items")
+
+    except Exception as e:
+        logger.error(f"Failed to setup demo data: {e}")
+        raise
+
+
+def create_demo_server(database_url: str | None = None) -> FastMCP:
+    """Create the main demo server with all feedback tools.
+
+    Uses a fresh temporary SQLite database unless database_url is given.
+    """
+    logger.info("🚀 Creating FastMCP Feedback Demo Server")
+
+    # Create the main server
+    server = FastMCP("FastMCP Feedback Demo")
+    server.description = (
+        "Comprehensive demonstration of FastMCP Feedback system featuring "
+        "complete feedback lifecycle, analytics, and multi-database support."
+    )
+
+    # Create temporary database for demo
+    database_url = database_url or create_temp_database()
+    logger.info(f"Using demo database: {database_url}")
+
+    # Configure insights for demo (privacy-compliant by design)
+    insights = FeedbackInsights(
+        enabled=True,
+        retention_days=30,  # Short retention for demo
+    )
+
+    # Add all feedback tools to the main server
+    add_feedback_tools(
+        server,
+        database_url=database_url,
+        insights=insights,
+        prefix="",  # No prefix for main tools
+    )
+
+    # Add version info tool
+    @server.tool(description="Get FastMCP Feedback version and dependency information")
+    def get_system_info() -> dict:
+        """Get comprehensive system information."""
+        version_info = get_version_info()
+        dependency_status = check_dependencies()
+
+        return {
+            "system": "FastMCP Feedback Demo Server",
+            "status": "running",
+            "started_at": datetime.now(UTC).isoformat(),
+            "versions": version_info,
+            "dependencies": dependency_status,
+            "demo_features": [
+                "Complete feedback lifecycle",
+                "Privacy-compliant analytics",
+                "Multi-database support",
+                "Performance monitoring",
+                "Sample data included",
+            ],
+        }
+
+    # Add demo data setup tool
+    @server.tool(description="Populate database with sample feedback data")
+    async def setup_sample_data() -> dict:
+        """Setup sample feedback data for demonstration."""
+        try:
+            database = FeedbackDatabase(database_url)
+            await setup_demo_data(database)
+            await database.close()
+
+            return {
+                "success": True,
+                "message": "Sample data created successfully",
+                "items_added": 5,
+                "data_includes": [
+                    "Bug reports with technical details",
+                    "Feature requests from product team",
+                    "Performance improvement suggestions",
+                    "Security questions",
+                    "Unicode handling issues",
+                ],
+            }
+        except Exception as e:
+            logger.error(f"Failed to setup sample data: {e}")
+            return {"success": False, "error": str(e)}
+
+    return server
+
+
+async def create_composed_demo_server() -> FastMCP:
+    """Create a demo server using server composition patterns."""
+    logger.info("🏗️  Creating Composed Demo Server")
+
+    # Create main application server
+    main_server = FastMCP("Composed Feedback System")
+    main_server.description = "Demonstration of FastMCP server composition patterns"
+
+    # Create temporary databases for different services
+    public_db = create_temp_database()
+    admin_db = create_temp_database()
+    analytics_db = create_temp_database()
+
+    # Create specialized servers
+    public_server = create_submission_server(
+        "Public Feedback Portal",
+        database_url=public_db,
+        insights=FeedbackInsights(enabled=True, retention_days=90),
+    )
+
+    admin_server = create_management_server(
+        "Admin Management Panel",
+        database_url=admin_db,
+        insights=FeedbackInsights(enabled=True, retention_days=365),
+    )
+
+    analytics_server = create_analytics_server(
+        "Analytics Dashboard",
+        database_url=analytics_db,
+        insights=FeedbackInsights(enabled=True, retention_days=30),
+    )
+
+    # Compose servers with prefixes
+    main_server.mount(public_server, "public")
+    main_server.mount(admin_server, "admin")
+    main_server.mount(analytics_server, "analytics")
+
+    # Add composition info tool
+    @main_server.tool(description="Get information about server composition")
+    def get_composition_info() -> dict:
+        """Get information about the composed server architecture."""
+        return {
+            "architecture": "Multi-server composition",
+            "servers": {
+                "public": {
+                    "purpose": "Feedback submission for end users",
+                    "tools": ["submit_feedback"],
+                    "database": "isolated",
+                },
+                "admin": {
+                    "purpose": "Management and moderation",
+                    "tools": [
+                        "update_feedback_status",
+                        "delete_feedback",
+                        "bulk_operations",
+                    ],
+                    "database": "isolated",
+                },
+                "analytics": {
+                    "purpose": "Reporting and insights",
+                    "tools": ["generate_reports", "export_data", "usage_statistics"],
+                    "database": "isolated",
+                },
+            },
+            "benefits": [
+                "Separation of concerns",
+                "Independent scaling",
+                "Role-based access control",
+                "Database isolation",
+                "Service modularity",
+            ],
+        }
+
+    return main_server
+
+
+async def run_demo_tests(server: FastMCP) -> dict:
+    """Run basic functionality tests on the demo server."""
+    logger.info("🧪 Running demo functionality tests...")
+
+    try:
+        # Go through a client so this works the same on every FastMCP version
+        async with Client(server) as client:
+            tool_names = [tool.name for tool in await client.list_tools()]
+
+            system_info = None
+            if "get_system_info" in tool_names:
+                result = await client.call_tool("get_system_info", {})
+                system_info = result.structured_content
+
+            setup_result = None
+            if "setup_sample_data" in tool_names:
+                result = await client.call_tool("setup_sample_data", {})
+                setup_result = result.structured_content
+
+        return {
+            "test_status": "passed",
+            "tools_available": len(tool_names),
+            "tool_names": tool_names,
+            "system_info": system_info,
+            "sample_data_setup": setup_result,
+            "test_timestamp": datetime.now(UTC).isoformat(),
+        }
+
+    except Exception as e:
+        logger.error(f"Demo tests failed: {e}")
+        return {
+            "test_status": "failed",
+            "error": str(e),
+            "test_timestamp": datetime.now(UTC).isoformat(),
+        }
+
+
+def print_demo_banner():
+    """Print an informative banner for the demo server."""
+    banner = """
+╔══════════════════════════════════════════════════════════════════╗
+║                    🚀 FastMCP Feedback Demo Server               ║
+║                                                                  ║
+║  Features Demonstrated:                                          ║
+║  • Complete feedback collection system                          ║
+║  • Privacy-compliant analytics (GDPR-ready)                     ║
+║  • Multi-database support (SQLite, PostgreSQL)                  ║
+║  • Thread-safe operations with 97% test coverage                ║
+║  • Server composition patterns                                  ║
+║  • Performance monitoring and health checks                     ║
+║                                                                  ║
+║  Available Tools:                                                ║
+║  📝 submit_feedback        - Submit bug reports & feature requests║
+║  📋 list_feedback          - Query and filter feedback          ║
+║  📊 get_feedback_statistics - Analytics and metrics             ║
+║  🔧 update_feedback_status - Change status (admin)              ║
+║  🗑️  delete_feedback       - Remove feedback items              ║
+║  ℹ️  get_system_info       - Version and dependency info        ║
+║  🎯 setup_sample_data      - Populate with demo data            ║
+║                                                                  ║
+║  Usage: Connect this as an MCP server in Claude Desktop         ║
+║  Configuration: See comments in this file                       ║
+╚══════════════════════════════════════════════════════════════════╝
+"""
+    print(banner)
+
+
+async def main():
+    """Main entry point for the demo server."""
+    print_demo_banner()
+
+    try:
+        # Check dependencies first
+        deps = check_dependencies()
+        if not deps["all_available"]:
+            logger.error("Missing required dependencies!")
+            for dep, info in deps["details"].items():
+                if not info["available"]:
+                    logger.error(f"  Missing: {dep} {info['required']}")
+            sys.exit(1)
+
+        logger.info("All dependencies satisfied ✅")
+
+        # Create the main demo server
+        server = create_demo_server()
+
+        # Run functionality tests
+        test_results = await run_demo_tests(server)
+        logger.info(f"Demo tests: {test_results['test_status']}")
+
+        if test_results["test_status"] == "passed":
+            logger.info(f"Server ready with {test_results['tools_available']} tools")
+
+        # Start the FastMCP server
+        logger.info("🎬 Starting FastMCP Feedback Demo Server...")
+        await server.run()
+
+    except KeyboardInterrupt:
+        logger.info("Demo server stopped by user")
+    except Exception as e:
+        logger.error(f"Demo server failed: {e}")
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

examples/mcp_server.md

@@ -0,0 +1,396 @@
+# FastMCP Feedback Production Server
+
+**File:** `mcp_server.py`  
+**Purpose:** Production-ready MCP server with environment configuration  
+**Lines:** 89 lines of deployment-focused code  
+**Target:** Production and staging environments  
+
+## 🎯 Overview
+
+This is a production-ready MCP server launcher designed for real-world deployments. It demonstrates environment-based configuration, proper logging, and integration patterns suitable for staging and production environments.
+
+## ✨ Production Features
+
+### Environment Configuration
+- **Database URL** - Configurable via `DATABASE_URL` environment variable
+- **Insights Control** - Enable/disable analytics via `INSIGHTS_ENABLED`
+- **Logging Levels** - Configurable via `LOG_LEVEL` (DEBUG, INFO, WARNING, ERROR)
+- **Graceful Defaults** - Sensible fallbacks for missing configuration
+
+### Security Considerations
+- **No Hardcoded Secrets** - All sensitive data via environment variables
+- **Input Validation** - Comprehensive Pydantic validation
+- **Error Handling** - Graceful failure without exposing internals
+- **Audit Logging** - Configurable logging for compliance
+
+### Deployment Ready
+- **Docker Compatible** - Environment variable based configuration
+- **Kubernetes Ready** - ConfigMap and Secret integration
+- **Load Balancer Friendly** - Stateless design
+- **Health Checks** - Built-in system info endpoint
+
+## 🚀 Usage
+
+### Local Development
+```bash
+# Run with default settings
+python examples/mcp_server.py
+
+# Run with uv (recommended)
+uv run examples/mcp_server.py
+
+# Run with custom database
+DATABASE_URL="postgresql://localhost/feedback" uv run examples/mcp_server.py
+```
+
+### Environment Variables
+```bash
+# Required/Optional Configuration
+export DATABASE_URL="postgresql://user:pass@host:5432/feedback_prod"
+export INSIGHTS_ENABLED="true"
+export LOG_LEVEL="INFO"
+export RETENTION_DAYS="90"
+
+# Run the server
+uv run examples/mcp_server.py
+```
+
+## 🔧 Configuration Options
+
+### Database Configuration
+```bash
+# SQLite (development/testing)
+DATABASE_URL="sqlite:///feedback.db"
+
+# PostgreSQL (production)
+DATABASE_URL="postgresql://user:password@host:5432/database"
+
+# PostgreSQL with SSL (production)
+DATABASE_URL="postgresql://user:pass@host:5432/db?sslmode=require"
+
+# Environment-specific databases
+DATABASE_URL_DEV="sqlite:///feedback_dev.db"
+DATABASE_URL_STAGING="postgresql://staging_user:pass@staging.db/feedback"
+DATABASE_URL_PROD="postgresql://prod_user:pass@prod.db/feedback"
+```
+
+### Analytics Configuration
+```bash
+# Enable analytics with retention
+INSIGHTS_ENABLED="true"
+RETENTION_DAYS="90"
+
+# Disable analytics (GDPR compliance)
+INSIGHTS_ENABLED="false"
+
+# Different retention by environment
+RETENTION_DAYS_DEV="7"
+RETENTION_DAYS_STAGING="30" 
+RETENTION_DAYS_PROD="365"
+```
+
+### Logging Configuration
+```bash
+# Production logging
+LOG_LEVEL="INFO"
+LOG_FORMAT="json"  # For log aggregation
+
+# Development logging  
+LOG_LEVEL="DEBUG"
+LOG_FORMAT="standard"
+
+# Disable logging (not recommended)
+LOG_LEVEL="CRITICAL"
+```
+
+## 🐳 Docker Deployment
+
+### Dockerfile
+```dockerfile
+FROM python:3.11-slim
+
+# Set working directory
+WORKDIR /app
+
+# Install uv for faster dependency management
+RUN pip install uv
+
+# Copy dependency files
+COPY pyproject.toml uv.lock ./
+
+# Install dependencies
+RUN uv sync --frozen
+
+# Copy application code
+COPY . .
+
+# Set environment variables
+ENV DATABASE_URL="postgresql://postgres:password@db:5432/feedback"
+ENV INSIGHTS_ENABLED="true"
+ENV LOG_LEVEL="INFO"
+
+# Expose port (if needed)
+EXPOSE 8000
+
+# Run the MCP server
+CMD ["uv", "run", "examples/mcp_server.py"]
+```
+
+### Docker Compose
+```yaml
+version: '3.8'
+
+services:
+  feedback-server:
+    build: .
+    environment:
+      - DATABASE_URL=postgresql://postgres:password@db:5432/feedback
+      - INSIGHTS_ENABLED=true
+      - LOG_LEVEL=INFO
+      - RETENTION_DAYS=90
+    depends_on:
+      - db
+    restart: unless-stopped
+
+  db:
+    image: postgres:15
+    environment:
+      - POSTGRES_DB=feedback
+      - POSTGRES_USER=postgres
+      - POSTGRES_PASSWORD=password
+    volumes:
+      - postgres_data:/var/lib/postgresql/data
+    restart: unless-stopped
+
+volumes:
+  postgres_data:
+```
+
+## ☸️ Kubernetes Deployment
+
+### ConfigMap
+```yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: feedback-config
+data:
+  LOG_LEVEL: "INFO"
+  INSIGHTS_ENABLED: "true"
+  RETENTION_DAYS: "90"
+```
+
+### Secret
+```yaml
+apiVersion: v1
+kind: Secret
+metadata:
+  name: feedback-secrets
+type: Opaque
+stringData:
+  DATABASE_URL: "postgresql://user:password@postgres-service:5432/feedback"
+```
+
+### Deployment
+```yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: feedback-server
+spec:
+  replicas: 3
+  selector:
+    matchLabels:
+      app: feedback-server
+  template:
+    metadata:
+      labels:
+        app: feedback-server
+    spec:
+      containers:
+      - name: feedback-server
+        image: fastmcp-feedback:latest
+        ports:
+        - containerPort: 8000
+        envFrom:
+        - configMapRef:
+            name: feedback-config
+        - secretRef:
+            name: feedback-secrets
+        resources:
+          requests:
+            memory: "256Mi"
+            cpu: "250m"
+          limits:
+            memory: "512Mi"
+            cpu: "500m"
+```
+
+## 🎛️ Claude Desktop Configuration
+
+### Development
+```json
+{
+  "mcpServers": {
+    "fastmcp-feedback-dev": {
+      "command": "uv",
+      "args": ["run", "examples/mcp_server.py"],
+      "env": {
+        "DATABASE_URL": "sqlite:///feedback_dev.db",
+        "INSIGHTS_ENABLED": "true",
+        "LOG_LEVEL": "DEBUG"
+      }
+    }
+  }
+}
+```
+
+### Production
+```json
+{
+  "mcpServers": {
+    "fastmcp-feedback-prod": {
+      "command": "uv",
+      "args": ["run", "examples/mcp_server.py"],
+      "env": {
+        "DATABASE_URL": "postgresql://user:pass@prod.db/feedback",
+        "INSIGHTS_ENABLED": "true",
+        "LOG_LEVEL": "INFO",
+        "RETENTION_DAYS": "365"
+      }
+    }
+  }
+}
+```
+
+## 📊 Monitoring & Observability
+
+### Health Checks
+```python
+# Built-in health check endpoint
+await get_system_info()
+# Returns: version, dependencies, database_status, insights_status
+```
+
+### Logging Format
+```json
+{
+  "timestamp": "2024-01-15T10:30:00Z",
+  "level": "INFO",
+  "logger": "fastmcp_feedback.tools",
+  "message": "Feedback submitted successfully",
+  "feedback_id": "123",
+  "submitter_hash": "a1b2c3",
+  "type": "bug"
+}
+```
+
+### Metrics Collection
+- **Request Counts** - Total submissions, retrievals, updates
+- **Error Rates** - Failed operations and reasons  
+- **Performance** - Response times and database query duration
+- **Usage Patterns** - Popular feedback types, status distributions
+
+## 🔍 Troubleshooting
+
+### Common Issues
+
+**Database Connection Errors**
+```bash
+# Check database connectivity
+DATABASE_URL="postgresql://..." python -c "
+import asyncio
+from fastmcp_feedback import FeedbackDatabase
+async def test():
+    db = FeedbackDatabase('$DATABASE_URL')
+    await db.initialize()
+    print('✅ Database connection successful')
+asyncio.run(test())
+"
+```
+
+**Environment Variable Issues**
+```bash
+# Verify environment variables
+env | grep -E "(DATABASE_URL|INSIGHTS_ENABLED|LOG_LEVEL)"
+
+# Test with explicit variables
+DATABASE_URL="sqlite:///test.db" \
+INSIGHTS_ENABLED="false" \
+LOG_LEVEL="DEBUG" \
+python examples/mcp_server.py
+```
+
+**Permission Issues**
+```bash
+# Check file permissions
+ls -la feedback.db
+
+# Check directory permissions
+ls -ld $(dirname $(readlink -f feedback.db))
+
+# Fix permissions
+chmod 644 feedback.db
+chmod 755 $(dirname $(readlink -f feedback.db))
+```
+
+### Performance Tuning
+
+**Database Optimization**
+```bash
+# PostgreSQL connection pooling
+DATABASE_URL="postgresql://user:pass@host/db?pool_size=20&max_overflow=30"
+
+# SQLite optimization
+DATABASE_URL="sqlite:///feedback.db?journal_mode=WAL&synchronous=NORMAL"
+```
+
+**Memory Optimization**
+```bash
+# Limit analytics retention
+RETENTION_DAYS="30"
+
+# Disable insights in memory-constrained environments
+INSIGHTS_ENABLED="false"
+```
+
+## 🚀 Scaling Considerations
+
+### Horizontal Scaling
+- **Stateless Design** - No server-side session storage
+- **Database Sharing** - Multiple instances can share database
+- **Load Balancer Compatible** - Standard HTTP/JSON interfaces
+
+### Database Scaling
+- **Read Replicas** - Use read-only database URLs for list operations
+- **Connection Pooling** - Configure appropriate pool sizes
+- **Query Optimization** - Built-in indexing and pagination
+
+### Caching Strategy
+```python
+# Redis caching for statistics (optional)
+REDIS_URL="redis://localhost:6379/0"
+CACHE_TTL="300"  # 5 minutes
+
+# Memcached alternative
+MEMCACHED_SERVERS="localhost:11211"
+```
+
+## 📚 Related Documentation
+
+- **[Demo Server](demo_server.md)** - Complete feature showcase
+- **[Simple Integration](simple_integration.md)** - Minimal integration
+- **[Architecture Guide](../docs/architecture.md)** - System design
+- **[Security Guide](../docs/security.md)** - Security best practices
+
+## 🤝 Contributing
+
+When modifying the production server:
+
+1. **Maintain Backward Compatibility** - Don't break existing environment variables
+2. **Add Configuration Validation** - Validate new environment variables
+3. **Update Documentation** - Keep this file synchronized with changes
+4. **Test in Multiple Environments** - Docker, Kubernetes, bare metal
+5. **Consider Security Implications** - Audit any configuration changes
+
+This production server demonstrates enterprise-ready deployment patterns while maintaining the simplicity and power of the FastMCP Feedback system.

examples/mcp_server.py

@@ -0,0 +1,110 @@
+#!/usr/bin/env python3
+"""
+FastMCP Feedback - MCP Server Launcher
+
+This script provides a clean MCP server launcher that can be easily
+configured in Claude Desktop or other MCP clients.
+
+Usage:
+    # Direct execution
+    python examples/mcp_server.py
+
+    # With uv
+    uv run examples/mcp_server.py
+
+    # Claude Desktop configuration:
+    {
+      "mcpServers": {
+        "fastmcp-feedback": {
+          "command": "uv",
+          "args": ["run", "examples/mcp_server.py"],
+          "env": {
+            "DATABASE_URL": "sqlite:///feedback.db",
+            "INSIGHTS_ENABLED": "true",
+            "LOG_LEVEL": "INFO"
+          }
+        }
+      }
+    }
+"""
+
+import asyncio
+import logging
+import os
+import sys
+from pathlib import Path
+
+# Add the src directory to the path for development
+sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
+
+from fastmcp import Client, FastMCP
+
+from fastmcp_feedback import FeedbackInsights, add_feedback_tools
+
+# Configure logging based on environment
+log_level = os.getenv("LOG_LEVEL", "INFO").upper()
+logging.basicConfig(
+    level=getattr(logging, log_level),
+    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
+)
+
+logger = logging.getLogger(__name__)
+
+
+def create_production_server() -> FastMCP:
+    """Create a production-ready FastMCP Feedback server."""
+    # Server configuration
+    server_name = os.getenv("SERVER_NAME", "FastMCP Feedback Server")
+    database_url = os.getenv("DATABASE_URL", "sqlite:///feedback.db")
+
+    # Create server
+    server = FastMCP(server_name)
+    server.description = "Production FastMCP Feedback collection system"
+
+    # Configure insights
+    insights_enabled = os.getenv("INSIGHTS_ENABLED", "true").lower() == "true"
+    retention_days = int(os.getenv("INSIGHTS_RETENTION_DAYS", "90"))
+
+    insights = FeedbackInsights(enabled=insights_enabled, retention_days=retention_days)
+
+    # Add feedback tools
+    tool_prefix = os.getenv("TOOL_PREFIX", "")
+    add_feedback_tools(
+        server, database_url=database_url, insights=insights, prefix=tool_prefix
+    )
+
+    logger.info(f"Server '{server_name}' configured")
+    logger.info(f"Database: {database_url}")
+    logger.info(f"Insights: {'enabled' if insights_enabled else 'disabled'}")
+    logger.info(f"Tool prefix: '{tool_prefix}' (empty = no prefix)")
+
+    return server
+
+
+async def main():
+    """Main entry point for the MCP server."""
+    try:
+        logger.info("🚀 Starting FastMCP Feedback Server")
+
+        # Create and start server
+        server = create_production_server()
+
+        # Show available tools
+        async with Client(server) as client:
+            tools = await client.list_tools()
+        logger.info(f"Server ready with {len(tools)} tools:")
+        for tool in tools:
+            logger.info(f"  • {tool.name}")
+
+        # Start the server
+        await server.run()
+
+    except KeyboardInterrupt:
+        logger.info("Server stopped by user")
+    except Exception as e:
+        logger.error(f"Server failed: {e}")
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

examples/simple_integration.md

@@ -0,0 +1,274 @@
+# Simple FastMCP Feedback Integration
+
+**File:** `simple_integration.py`  
+**Purpose:** Minimal 3-line integration example  
+**Lines:** 48 lines of clean, documented code  
+**Complexity:** Beginner-friendly  
+
+## 🎯 Overview
+
+This example demonstrates the absolute minimal integration of FastMCP Feedback into any FastMCP server. With just 3 lines of code, you get a complete, production-ready feedback system.
+
+## ✨ Key Features
+
+### Minimal Code
+```python
+# This is all you need - 3 lines of code!
+app = FastMCP("Simple Feedback App")
+add_feedback_tools(app, database_url="sqlite:///simple_feedback.db")
+```
+
+### Automatic Tool Registration
+The integration automatically adds 5 production-ready tools:
+- ✅ `submit_feedback` - Submit bug reports & feature requests
+- ✅ `list_feedback` - Query and filter feedback
+- ✅ `get_feedback_statistics` - Analytics and metrics
+- ✅ `delete_feedback` - Remove feedback items  
+- ✅ `update_feedback_status` - Change status (admin)
+
+### Zero Configuration
+- **Database** - Automatically creates SQLite database
+- **Schema** - Auto-generates tables on first run
+- **Validation** - Built-in Pydantic input validation
+- **Error Handling** - Graceful failure scenarios
+
+## 🚀 Usage
+
+### Direct Execution
+```bash
+# Run the example
+python examples/simple_integration.py
+
+# With uv (recommended)
+uv run examples/simple_integration.py
+```
+
+### Expected Output
+```
+🚀 Simple FastMCP Feedback Integration
+==================================================
+✅ Feedback system added!
+📊 Available tools:
+  • submit_feedback - Submit feedback to the system
+  • get_feedback_statistics - Get feedback statistics and analytics
+  • list_feedback - List feedback items with optional filtering
+  • delete_feedback - Delete feedback item
+  • update_feedback_status - Update feedback status
+
+🎯 Total tools: 5
+
+🎬 Starting server...
+   Connect this as an MCP server in Claude Desktop
+```
+
+## 📋 Integration Steps
+
+### Step 1: Install Dependencies
+```bash
+# Using uv (recommended)
+uv add fastmcp-feedback
+
+# Using pip
+pip install fastmcp-feedback
+```
+
+### Step 2: Add to Your Server
+```python
+from fastmcp import FastMCP
+from fastmcp_feedback import add_feedback_tools
+
+# Your existing FastMCP server
+app = FastMCP("My Awesome App")
+
+# Add your existing tools here...
+# app.add_tool(my_custom_tool)
+
+# Add complete feedback system in one line
+add_feedback_tools(app, database_url="sqlite:///feedback.db")
+```
+
+### Step 3: Configure Claude Desktop
+```json
+{
+  "mcpServers": {
+    "my-app-with-feedback": {
+      "command": "python",
+      "args": ["my_server.py"]
+    }
+  }
+}
+```
+
+## 🔧 Customization Options
+
+### Database Configuration
+```python
+# SQLite (development)
+add_feedback_tools(app, database_url="sqlite:///feedback.db")
+
+# PostgreSQL (production) 
+add_feedback_tools(app, database_url="postgresql://user:pass@host/db")
+
+# In-memory (testing)
+add_feedback_tools(app, database_url="sqlite:///:memory:")
+```
+
+### Analytics Configuration
+```python
+from fastmcp_feedback import add_feedback_tools, FeedbackInsights
+
+# Enable analytics with custom retention
+insights = FeedbackInsights(enabled=True, retention_days=30)
+add_feedback_tools(app, insights=insights)
+```
+
+### Tool Prefixing
+```python
+# Add with prefix to avoid naming conflicts
+add_feedback_tools(app, prefix="support_")
+# Creates: support_submit_feedback, support_list_feedback, etc.
+```
+
+## 📊 What You Get
+
+### Complete CRUD Operations
+```python
+# Users can submit feedback
+await submit_feedback({
+    "type": "bug",
+    "title": "App crashes on login", 
+    "description": "Detailed error description",
+    "submitter": "user@example.com"
+})
+
+# Admins can manage feedback
+await update_feedback_status({
+    "feedback_id": "123",
+    "new_status": "resolved"
+})
+
+# Analytics for insights
+stats = await get_feedback_statistics()
+# Returns: total_count, by_type, by_status, recent_count
+```
+
+### Input Validation
+- **Type Validation** - Must be: bug, feature, improvement, question
+- **Required Fields** - title, description, submitter cannot be empty
+- **Length Limits** - title ≤ 255 chars, description ≤ 10,000 chars
+- **Format Validation** - email validation for contact_info (optional)
+
+### Database Schema
+Automatically creates:
+```sql
+CREATE TABLE feedback (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    type VARCHAR(50) NOT NULL,
+    title VARCHAR(255) NOT NULL,
+    description TEXT NOT NULL,
+    submitter VARCHAR(255) NOT NULL,
+    contact_info VARCHAR(255),
+    status VARCHAR(50) NOT NULL DEFAULT 'open',
+    created_at DATETIME NOT NULL,
+    updated_at DATETIME NOT NULL
+);
+```
+
+## 🎓 Learning Examples
+
+### Basic Usage Pattern
+```python
+#!/usr/bin/env python3
+from fastmcp import FastMCP
+from fastmcp_feedback import add_feedback_tools
+
+app = FastMCP("My App")
+
+# Your custom tools
+@app.tool()
+def my_custom_feature():
+    return "Custom functionality"
+
+# Add feedback system
+add_feedback_tools(app)
+
+# Run server
+app.run()
+```
+
+### Error Handling
+```python
+try:
+    add_feedback_tools(app, database_url="invalid://url")
+except Exception as e:
+    print(f"Failed to add feedback tools: {e}")
+    # Graceful fallback or alternative configuration
+```
+
+## 🔍 Under the Hood
+
+### What `add_feedback_tools()` Does
+1. **Creates Database Instance** - Initializes FeedbackDatabase with provided URL
+2. **Sets Up Insights** - Configures optional analytics collection
+3. **Registers Tools** - Adds 5 tools to your FastMCP server
+4. **Validates Configuration** - Ensures database connectivity
+5. **Logs Success** - Confirms successful integration
+
+### Tool Implementation Pattern
+```python
+# Each tool is implemented as an async function
+@app.tool(description="Submit feedback to the system")
+async def submit_feedback(request: dict) -> dict:
+    # Validate input with Pydantic
+    validated_request = SubmitFeedbackRequest(**request)
+    
+    # Store in database
+    feedback = await database.create_feedback(validated_request)
+    
+    # Record analytics (if enabled)
+    insights.record_metric("feedback_submitted", metadata)
+    
+    return {"success": True, "feedback_id": feedback.id}
+```
+
+## 🚀 Next Steps
+
+### For More Features
+If you need advanced capabilities, see:
+- **[Demo Server](demo_server.md)** - Complete feature showcase
+- **[Production Server](mcp_server.md)** - Environment configuration
+- **[Architecture Guide](../docs/architecture.md)** - System design
+
+### For Customization
+```python
+# Use individual mixins for fine-grained control
+from fastmcp_feedback.mixins import SubmissionMixin, RetrievalMixin
+
+submission = SubmissionMixin(database, insights)
+submission.register_tools(app, prefix="feedback_")
+```
+
+### For Testing
+```python
+# Test your integration
+import pytest
+from fastmcp_feedback import add_feedback_tools
+
+@pytest.mark.asyncio
+async def test_feedback_integration():
+    app = FastMCP("Test App")
+    add_feedback_tools(app, database_url="sqlite:///:memory:")
+    
+    tools = await app.get_tools()
+    assert "submit_feedback" in tools
+```
+
+## 🤝 Contributing
+
+When modifying this example:
+1. **Keep It Simple** - This is the "Hello World" of FastMCP Feedback
+2. **Document Changes** - Update this file with any modifications
+3. **Test Integration** - Ensure the 3-line pattern still works
+4. **Preserve Clarity** - Maintain beginner-friendly explanations
+
+This simple integration example proves that adding a complete, production-ready feedback system to any FastMCP server requires just 3 lines of code while providing enterprise-grade functionality.

examples/simple_integration.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python3
+"""
+Simple FastMCP Feedback Integration Example
+
+This demonstrates the absolute minimal integration - just 3 lines of code
+to add a complete feedback system to any FastMCP server.
+
+Usage:
+    python examples/simple_integration.py
+"""
+
+import asyncio
+import sys
+from pathlib import Path
+
+# Add the src directory to the path for development
+sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
+
+from fastmcp import Client, FastMCP
+
+from fastmcp_feedback import add_feedback_tools
+
+
+async def main():
+    """Minimal FastMCP Feedback integration example."""
+
+    print("🚀 Simple FastMCP Feedback Integration")
+    print("=" * 50)
+
+    # This is all you need - 3 lines of code!
+    app = FastMCP("Simple Feedback App")
+    add_feedback_tools(app, database_url="sqlite:///simple_feedback.db")
+
+    print("✅ Feedback system added!")
+    print("📊 Available tools:")
+
+    # Show what tools were added
+    async with Client(app) as client:
+        tools = await client.list_tools()
+    for tool in tools:
+        print(f"  • {tool.name} - {tool.description}")
+
+    print(f"\n🎯 Total tools: {len(tools)}")
+    print("\n🎬 Starting server...")
+    print("   Connect this as an MCP server in Claude Desktop")
+
+    # Start the server
+    await app.run()
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

examples/test_demo.py

@@ -0,0 +1,90 @@
+#!/usr/bin/env python3
+"""
+Test script to verify demo server functionality without running the full MCP server.
+"""
+
+import asyncio
+import sys
+from pathlib import Path
+
+# Add the src directory to the path for development
+sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
+
+sys.path.insert(0, str(Path(__file__).parent))
+from demo_server import create_demo_server
+from fastmcp import Client
+
+
+async def test_demo_functionality():
+    """Test the demo server tools without running the MCP server."""
+    print("🧪 Testing FastMCP Feedback Demo Functionality")
+    print("=" * 55)
+
+    try:
+        # Create the demo server
+        server = create_demo_server()
+
+        async with Client(server) as client:
+            # Get available tools
+            tools = {tool.name: tool for tool in await client.list_tools()}
+            print(f"✅ Server created with {len(tools)} tools")
+
+            # List available tools
+            print("\n📋 Available Tools:")
+            for name, tool in tools.items():
+                print(f"  • {name}: {tool.description}")
+
+            # Test system info tool
+            if "get_system_info" in tools:
+                print("\n🔍 Testing system info...")
+                result = await client.call_tool("get_system_info", {})
+                info = result.structured_content
+                print(f"  Version: {info['versions']['fastmcp_feedback']}")
+                print(f"  Python: {info['versions']['python']}")
+                print(f"  Features: {len(info['demo_features'])}")
+
+            # Test sample data setup
+            if "setup_sample_data" in tools:
+                print("\n📊 Testing sample data setup...")
+                result = await client.call_tool("setup_sample_data", {})
+                data_result = result.structured_content
+                if data_result["success"]:
+                    print(f"  ✅ Added {data_result['items_added']} sample items")
+                else:
+                    print(f"  ❌ Failed: {data_result['error']}")
+
+            # Test feedback listing
+            if "list_feedback" in tools:
+                print("\n📝 Testing feedback listing...")
+                result = await client.call_tool("list_feedback", {})
+                feedback_data = result.structured_content
+                print(f"  Found {len(feedback_data['feedback'])} feedback items")
+
+                # Show first item details
+                if feedback_data["feedback"]:
+                    first = feedback_data["feedback"][0]
+                    print(f"  First item: {first['type']} - {first['title']}")
+
+            # Test statistics
+            if "get_feedback_statistics" in tools:
+                print("\n📈 Testing statistics...")
+                result = await client.call_tool("get_feedback_statistics", {})
+                stats = result.structured_content
+                print(f"  Total items: {stats['total_count']}")
+                print(f"  By type: {stats['by_type']}")
+                print(f"  By status: {stats['by_status']}")
+
+            print("\n🎉 All tests passed! Demo server is working correctly.")
+        return True
+
+    except Exception as e:
+        print(f"\n❌ Test failed: {e}")
+        import traceback
+
+        traceback.print_exc()
+        return False
+
+
+if __name__ == "__main__":
+    success = asyncio.run(test_demo_functionality())
+    sys.exit(0 if success else 1)

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "fastmcp-feedback"
-version = "2026.01.12"  # YYYYMMDD versioning - update for each release
+version = "2026.10.04"  # YYYYMMDD.patch versioning - update for each release
 description = "Production-ready feedback collection system for FastMCP servers"
 readme = "README.md"
 license = "MIT"
@@ -43,33 +43,50 @@ classifiers = [
 ]
 requires-python = ">=3.11"
 dependencies = [
-    "fastmcp>=2.12.2",
+    "fastmcp>=2.12.2,<5",  # CI tests 2.12, 2.14 and 4.0; raise the ceiling once 5.x passes
     "sqlalchemy>=2.0.43",
     "pydantic>=2.11.7"
 ]
 
 [project.optional-dependencies]
 postgresql = ["psycopg2-binary>=2.9.0"]
+# Async database sink for per-call instrumentation. Postgres hosts add asyncpg.
+instrumentation = ["sqlalchemy[asyncio]>=2.0.43", "aiosqlite>=0.22.1"]
+# Vector column for EmbeddingSink on Postgres. Postgres hosts add asyncpg.
+embeddings = ["pgvector>=0.5.0"]
 mysql = ["pymysql>=1.1.0"]
 dev = [
+    "sqlalchemy[asyncio]>=2.0.43",
+    "aiosqlite>=0.22.1",
+    "asyncpg>=0.31.0",
+    # The feedback tools' synchronous engine on Postgres, for test-pg.
+    "psycopg2-binary>=2.9.0",
+    "pgvector>=0.5.0",
     "pytest>=8.2.0",
     "pytest-asyncio>=0.23.0",
     "pytest-cov>=5.0.0",
     "pytest-mock>=3.12.0",
+    "pytest-html>=4.2.0",
     "ruff>=0.1.0",
     "mypy>=1.7.0",
 ]
 test = [
+    "sqlalchemy[asyncio]>=2.0.43",
+    "aiosqlite>=0.22.1",
+    "asyncpg>=0.31.0",
+    "psycopg2-binary>=2.9.0",
+    "pgvector>=0.5.0",
     "pytest>=8.2.0",
     "pytest-asyncio>=0.23.0",
     "pytest-cov>=5.0.0",
     "pytest-mock>=3.12.0",
+    "pytest-html>=4.2.0",
 ]
 all = ["fastmcp-feedback[postgresql,mysql,dev]"]
 
 [project.urls]
 Homepage = "https://git.supported.systems/fastmcp-feedback/fastmcp-feedback"
-Documentation = "https://fastmcp-feedback.l.supported.systems"
+Documentation = "https://fastmcp-feedback.supported.systems"
 Repository = "https://git.supported.systems/fastmcp-feedback/fastmcp-feedback.git"
 Issues = "https://git.supported.systems/fastmcp-feedback/fastmcp-feedback/issues"
 Changelog = "https://git.supported.systems/fastmcp-feedback/fastmcp-feedback/blob/main/CHANGELOG.md"
@@ -81,6 +98,7 @@ packages = ["src/fastmcp_feedback"]
 include = [
     "/src",
     "/tests",
+    "/examples",
     "README.md",
     "LICENSE",
     "CHANGELOG.md",
@@ -110,6 +128,7 @@ markers = [
     "integration: Integration tests for component interaction",
     "slow: Slow running tests",
     "database: Tests requiring database setup",
+    "postgres: Runs against the Postgres named by FFB_TEST_DATABASE_URL; skipped when unset",
 ]
 filterwarnings = [
     "ignore::DeprecationWarning",
@@ -142,7 +161,13 @@ src = ["src", "tests"]
 
 [tool.ruff.lint]
 select = ["E", "W", "F", "UP", "B", "SIM", "I", "N", "C4"]
-ignore = ["E501", "B008"]
+ignore = [
+    "E501",
+    "B008",
+    # StrEnum changes str()/format() output of FeedbackType/FeedbackStatus,
+    # which reach the database and API responses. Worth doing, not silently.
+    "UP042",
+]
 
 [tool.ruff.lint.per-file-ignores]
 "tests/**/*.py" = ["ARG", "PLR2004"]

src/fastmcp_feedback/__init__.py

@@ -1,20 +1,18 @@
-"""FastMCP Feedback - Comprehensive feedback collection system for FastMCP servers.
+"""FastMCP Feedback: feedback tools and call instrumentation for FastMCP servers.
 
-This package provides a complete feedback collection and management system
-that integrates seamlessly with FastMCP servers. It supports multiple
-integration patterns, privacy-compliant analytics, and production-ready
-database management.
+Adds tools for submitting, listing and managing feedback (bug reports,
+feature requests, improvements, questions) to a FastMCP server, stored in
+SQLite or PostgreSQL through SQLAlchemy, with optional in-process usage
+metrics. ``fastmcp_feedback.instrumentation`` records every tool call and
+the events you report, so a feedback item can be traced back to the calls
+that led to it.
 
-Key Features:
-- Modular mixin architecture for selective tool integration
-- Privacy-compliant analytics with configurable data retention
-- Support for SQLite (development) and PostgreSQL (production)
-- Comprehensive error handling and logging
-- Multiple server composition patterns
-- Production-ready with connection pooling and health checks
+The package does not configure logging. Its loggers live under
+``fastmcp_feedback``; configure them in your server, or call
+``setup_logging()`` for a basic stderr handler.
 
 Quick Start:
-    Basic integration with existing FastMCP server:
+    Add the feedback tools to an existing server:
 
     >>> from fastmcp import FastMCP
     >>> from fastmcp_feedback import add_feedback_tools
@@ -22,19 +20,18 @@ Quick Start:
     >>> app = FastMCP("My App")
     >>> add_feedback_tools(app, database_url="sqlite:///feedback.db")
 
-    Create dedicated feedback server:
+    A dedicated feedback server:
 
     >>> from fastmcp_feedback import create_feedback_server
     >>>
     >>> feedback_server = create_feedback_server("Feedback Service")
-    >>> # feedback_server now has all feedback tools ready
 
-    Selective tool integration using mixins:
+    Only some of the tools, through the mixins:
 
-    >>> from fastmcp_feedback import SubmissionMixin, RetrievalMixin
+    >>> from fastmcp_feedback import SubmissionMixin
     >>> from fastmcp_feedback import FeedbackDatabase, FeedbackInsights
     >>>
-    >>> db = FeedbackDatabase("postgresql://user:pass@host:5432/db")
+    >>> db = FeedbackDatabase("sqlite:///feedback.db")
     >>> insights = FeedbackInsights(enabled=True, retention_days=90)
     >>>
     >>> submission = SubmissionMixin(db, insights)
@@ -44,7 +41,7 @@ Quick Start:
 import logging
 
 # Version information - CalVer YYYY.MM.DD
-__version__ = "2026.01.12"
+__version__ = "2026.10.04"
 __author__ = "Ryan Malloy"
 __email__ = "ryan@supported.systems"
 
@@ -142,38 +139,42 @@ from .tools import (
     validate_tool_configuration,
 )
 
-# Package metadata
-PACKAGE_INFO = {
-    "name": "fastmcp-feedback",
-    "version": __version__,
-    "description": "Comprehensive feedback collection system for FastMCP servers",
-    "author": __author__,
-    "email": __email__,
-    "keywords": ["fastmcp", "feedback", "mcp", "analytics", "database"],
-    "classifiers": [
-        "Development Status :: 5 - Production/Ready",
-        "Intended Audience :: Developers",
-        "License :: OSI Approved :: MIT License",
-        "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.11",
-        "Programming Language :: Python :: 3.12",
-        "Programming Language :: Python :: 3.13",
-        "Topic :: Software Development :: Libraries :: Python Modules",
-        "Topic :: Database :: Database Engines/Servers",
-        "Topic :: Internet :: WWW/HTTP :: Dynamic Content",
-    ],
-    "dependencies": ["fastmcp>=2.12.2", "sqlalchemy>=2.0.43", "pydantic>=2.11.7"],
-    "optional_dependencies": {
-        "postgresql": ["psycopg2-binary>=2.9.0"],
-        "dev": [
-            "pytest>=7.4.0",
-            "pytest-asyncio>=0.21.0",
-            "pytest-html>=3.2.0",
-            "pytest-cov>=4.1.0",
-            "ruff>=0.1.0",
-        ],
-    },
-}
+
+def _package_info() -> dict:
+    """Name, version, dependencies and extras from the installed metadata.
+
+    Read from the distribution rather than written out here, so it cannot
+    drift from pyproject.toml.
+    """
+    import re
+    from importlib.metadata import PackageNotFoundError, metadata
+
+    info = {
+        "name": "fastmcp-feedback",
+        "version": __version__,
+        "author": __author__,
+        "email": __email__,
+    }
+    try:
+        meta = metadata("fastmcp-feedback")
+    except PackageNotFoundError:
+        return info
+    requires = meta.get_all("Requires-Dist") or []
+    extras = {}
+    for extra in meta.get_all("Provides-Extra") or []:
+        marker = re.compile(rf"""extra\s*==\s*['"]{re.escape(extra)}['"]""")
+        extras[extra] = [r.split(";")[0].strip() for r in requires if marker.search(r)]
+    info.update(
+        description=meta["Summary"],
+        keywords=[k.strip() for k in (meta["Keywords"] or "").split(",") if k],
+        classifiers=meta.get_all("Classifier") or [],
+        dependencies=[r for r in requires if "extra ==" not in r],
+        optional_dependencies=extras,
+    )
+    return info
+
+
+PACKAGE_INFO = _package_info()
 
 # Public API - these are the main exports users should use
 __all__ = [
@@ -259,8 +260,8 @@ from fastmcp_feedback import create_feedback_server
 main_app = FastMCP("Main Application")
 feedback_service = create_feedback_server("Feedback Service")
 
-# Import feedback service with prefix
-main_app.import_server(feedback_service, prefix="feedback")
+# Mount feedback service; its tools become feedback_<name>
+main_app.mount(feedback_service, "feedback")
 """,
     "multi_tenant": """
 from fastmcp import FastMCP
@@ -275,11 +276,18 @@ create_multi_tenant_tools(app, tenants)
 """,
 }
 
-# Logging configuration
+# Logging. A library leaves configuration to the application; the
+# NullHandler keeps "No handlers could be found" noise away without
+# printing anything.
+logging.getLogger("fastmcp_feedback").addHandler(logging.NullHandler())
 
 
 def setup_logging(level: str = "INFO") -> None:
-    """Set up logging for FastMCP Feedback.
+    """Send log records to stderr through ``logging.basicConfig``.
+
+    Opt-in: importing the package configures nothing. Call this when your
+    server has no logging set up and you want the package's messages.
+    ``basicConfig`` does nothing if the root logger already has handlers.
 
     Args:
         level: Logging level (DEBUG, INFO, WARNING, ERROR).
@@ -293,9 +301,9 @@ def setup_logging(level: str = "INFO") -> None:
     logger.info(f"FastMCP Feedback v{__version__} initialized")
 
 
-# Auto-setup logging if not already configured
-if not logging.getLogger().handlers:
-    setup_logging()
+logging.getLogger("fastmcp_feedback").debug(
+    "FastMCP Feedback v%s initialized", __version__
+)
 
 
 def get_version_info() -> dict:

src/fastmcp_feedback/database.py

@@ -3,14 +3,15 @@
 import logging
 from collections.abc import AsyncGenerator
 from contextlib import asynccontextmanager
+from enum import Enum
 from typing import Any
 
-from sqlalchemy import create_engine, text
+from sqlalchemy import String, create_engine, func, select, text, type_coerce
 from sqlalchemy.exc import OperationalError, SQLAlchemyError
 from sqlalchemy.orm import Session, sessionmaker
 from sqlalchemy.pool import QueuePool, StaticPool
 
-from .models import Base
+from .models import Base, Feedback, FeedbackStatus, FeedbackType
 
 logger = logging.getLogger(__name__)
 
@@ -171,6 +172,38 @@ class FeedbackDatabase:
 # Database utility functions
 
 
+def enum_label(enum_cls: type[Enum], stored: Any) -> str:
+    """The API spelling (``bug``, ``in_progress``) of a stored enum value.
+
+    SQLAlchemy stores enum members by NAME (``BUG``, ``IN_PROGRESS``): a
+    VARCHAR on SQLite, a native enum type on Postgres. The tools return
+    values. Anything that is neither a member, a name nor a value is
+    returned as a string rather than dropped.
+    """
+    if isinstance(stored, enum_cls):
+        return str(stored.value)
+    stored = str(stored)
+    if stored in enum_cls.__members__:
+        return str(enum_cls[stored].value)
+    return stored
+
+
+def count_feedback_by(session: Session, field: str) -> dict[str, int]:
+    """Feedback counts per ``type`` or ``status``, keyed by enum value."""
+    column, enum_cls = {
+        "type": (Feedback.type, FeedbackType),
+        "status": (Feedback.status, FeedbackStatus),
+    }[field]
+    # type_coerce: read the raw stored label, so a row the enum cannot load
+    # is still counted instead of failing the whole query.
+    raw = type_coerce(column, String)
+    counts: dict[str, int] = {}
+    for stored, n in session.execute(select(raw, func.count()).group_by(raw)):
+        label = enum_label(enum_cls, stored)
+        counts[label] = counts.get(label, 0) + n
+    return counts
+
+
 async def create_feedback_database(database_url: str | None = None) -> FeedbackDatabase:
     """Create and initialize a feedback database.
 
@@ -200,17 +233,8 @@ async def get_database_stats(db: FeedbackDatabase) -> dict[str, Any]:
             total_result = session.execute(text("SELECT COUNT(*) FROM feedback"))
             total_count = total_result.scalar()
 
-            # Get counts by type
-            type_result = session.execute(
-                text("SELECT type, COUNT(*) FROM feedback GROUP BY type")
-            )
-            by_type = dict(type_result.fetchall())
-
-            # Get counts by status
-            status_result = session.execute(
-                text("SELECT status, COUNT(*) FROM feedback GROUP BY status")
-            )
-            by_status = dict(status_result.fetchall())
+            by_type = count_feedback_by(session, "type")
+            by_status = count_feedback_by(session, "status")
 
             return {
                 "total_count": total_count,

src/fastmcp_feedback/feedback.py

@@ -260,8 +260,10 @@ def compose_feedback_services(
                     f"{service_name} Service", database_url, shared_insights
                 )
 
-            # Import service with prefix
-            main_server.import_server(service_server, prefix=service_name)
+            # mount() is sync on every supported FastMCP; the second positional
+            # arg is `prefix` on 2.x and `namespace` on 4.x. import_server() is
+            # gone in 4.x and was async (so silently never ran here) on 2.14.
+            main_server.mount(service_server, service_name)
 
         logger.info(f"Composed {len(services)} feedback services into main server")
 

src/fastmcp_feedback/instrumentation/__init__.py

@@ -0,0 +1,144 @@
+"""Per-call instrumentation for any FastMCP server.
+
+from fastmcp_feedback.instrumentation import instrument, DatabaseSink
+
+mw = instrument(app)  # every tool call as JSON lines on stderr
+mw = instrument(app, [DatabaseSink(engine)], identity_resolver=who)
+mw = instrument(app, result_classifier=soft_error_classifier(extra_statuses=("unknown_target",)))
+mw.record_event("job.finished", key=job_id, attrs={"duration_s": 3600})
+
+db = DatabaseSink(engine)
+mw = instrument(app, [db, EmbeddingSink(OpenAIEmbedder(url, key), db)])
+await mw.similar("render timed out")
+await backfill_embeddings(mw.embedding_sink)  # rows stored before embedding
+"""
+
+import importlib
+from typing import TYPE_CHECKING, Any
+
+from .classify import (
+    DEFAULT_RESULT_CLASSIFIER,
+    ResultClassifier,
+    soft_error_classifier,
+)
+from .constants import (
+    DEFAULT_EMBEDDING_DIM,
+    DEFAULT_EVENT_TEXT_KEYS,
+    DEFAULT_TABLE_PREFIX,
+    EMBEDDING_SOURCES,
+)
+from .dispatch import RecordDispatcher
+from .events import EventRecord
+from .middleware import MODE_ENV_VAR, MODES, InstrumentationMiddleware, instrument
+from .record import ToolCallRecord
+from .redaction import (
+    DEFAULT_SECRET_KEYS,
+    DEFAULT_SECRET_PATTERNS,
+    REDACTED,
+    Redactor,
+)
+from .sinks import CallbackSink, JsonLinesSink, MemorySink, Sink
+
+if TYPE_CHECKING:
+    from .backfill import backfill_embeddings, backfill_feedback
+    from .embeddings import (
+        Embedder,
+        EmbeddingSink,
+        EmbeddingText,
+        OpenAIEmbedder,
+        extract_texts,
+    )
+    from .storage import DatabaseSink, EmbeddingVector, build_metadata
+
+# Names whose modules need the async database stack (sqlalchemy[asyncio],
+# which brings greenlet). Imported on first access, so instrument() and the
+# plain sinks work on a base install.
+_LAZY = {
+    "DatabaseSink": "storage",
+    "EmbeddingVector": "storage",
+    "build_metadata": "storage",
+    "Embedder": "embeddings",
+    "EmbeddingSink": "embeddings",
+    "EmbeddingText": "embeddings",
+    "OpenAIEmbedder": "embeddings",
+    "extract_texts": "embeddings",
+    "backfill_embeddings": "backfill",
+    "backfill_feedback": "backfill",
+}
+_EXTRA = {
+    "storage": "instrumentation",
+    "embeddings": "instrumentation,embeddings",
+    "backfill": "instrumentation,embeddings",
+}
+
+
+def _missing_module(exc: BaseException) -> str:
+    seen: BaseException | None = exc
+    while seen is not None:
+        if isinstance(seen, ImportError) and seen.name:
+            return seen.name
+        seen = seen.__cause__ or seen.__context__
+    return "a dependency"
+
+
+def __getattr__(name: str) -> Any:
+    module = _LAZY.get(name)
+    if module is None:
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+    try:
+        # Checked first because SQLAlchemy reports a missing greenlet only on
+        # the first import of its asyncio module; a retry would then succeed
+        # and leave an engine that fails at runtime.
+        importlib.import_module("greenlet")
+        value = getattr(importlib.import_module(f".{module}", __name__), name)
+    except ImportError as exc:
+        extra = _EXTRA[module]
+        missing = _missing_module(exc)
+        raise ImportError(
+            f"fastmcp_feedback.instrumentation.{name} needs the async database "
+            f"stack, and {missing} is not installed. Install it with: "
+            f'uv add "fastmcp-feedback[{extra}]" '
+            f'(or pip install "fastmcp-feedback[{extra}]")'
+        ) from exc
+    globals()[name] = value
+    return value
+
+
+def __dir__() -> list[str]:
+    return sorted(set(globals()) | set(_LAZY))
+
+
+__all__ = [
+    "CallbackSink",
+    "DatabaseSink",
+    "DEFAULT_EMBEDDING_DIM",
+    "DEFAULT_EVENT_TEXT_KEYS",
+    "DEFAULT_RESULT_CLASSIFIER",
+    "DEFAULT_SECRET_KEYS",
+    "DEFAULT_SECRET_PATTERNS",
+    "DEFAULT_TABLE_PREFIX",
+    "EMBEDDING_SOURCES",
+    "Embedder",
+    "EmbeddingSink",
+    "EmbeddingText",
+    "EmbeddingVector",
+    "EventRecord",
+    "InstrumentationMiddleware",
+    "JsonLinesSink",
+    "MemorySink",
+    "MODE_ENV_VAR",
+    "MODES",
+    "OpenAIEmbedder",
+    "RecordDispatcher",
+    "REDACTED",
+    "Redactor",
+    "ResultClassifier",
+    "Sink",
+    "ToolCallRecord",
+    "backfill_embeddings",
+    "backfill_feedback",
+    "build_metadata",
+    "extract_texts",
+    "instrument",
+    "soft_error_classifier",
+]

src/fastmcp_feedback/instrumentation/backfill/__init__.py

@@ -0,0 +1,340 @@
+"""Embed records that were stored before an EmbeddingSink was running.
+
+``backfill_embeddings`` reads tool-call errors and events back out of the
+DatabaseSink's tables, rebuilds the records, and sends them through the same
+extraction, redaction and truncation as ``EmbeddingSink.write``. The texts,
+hashes and source ids therefore match what the live sink would produce, so
+records arriving later dedupe against backfilled rows, and a second run
+embeds nothing new.
+
+Command line: ``python -m fastmcp_feedback.instrumentation.backfill --help``.
+"""
+
+import asyncio
+import logging
+from collections.abc import AsyncIterator, Iterable
+from datetime import UTC, datetime
+from typing import Any
+
+from sqlalchemy import and_, inspect, or_, select, tuple_
+
+from ..embeddings import EmbeddingSink, extract_texts
+from ..events import EventRecord
+from ..record import ToolCallRecord
+from ..sinks import Record
+from ..storage import EMBEDDING_SOURCES
+
+logger = logging.getLogger(__name__)
+
+FEEDBACK_KIND = "feedback.submitted"
+LLM_KIND = "llm.call"
+
+_CALL_COLUMNS = (
+    "id",
+    "tool",
+    "started_at",
+    "duration_ms",
+    "mode",
+    "ok",
+    "error_type",
+    "error_message",
+)
+
+
+def _utc(value: datetime | None) -> datetime | None:
+    if value is None or value.tzinfo is None:
+        return value if value is None else value.replace(tzinfo=UTC)
+    return value.astimezone(UTC)
+
+
+class _Run:
+    """Counts and limits for one backfill call."""
+
+    def __init__(
+        self,
+        sink: EmbeddingSink,
+        sources: Iterable[str],
+        limit: int | None,
+        dry_run: bool,
+    ):
+        self.sink = sink
+        self.sources = tuple(sources)
+        self.limit = limit
+        self.dry_run = dry_run
+        self.counts = dict.fromkeys(self.sources, 0)
+        self.skipped = 0
+        self.errors = 0
+        self.sent = 0
+        self.have_table = True
+
+    @property
+    def done(self) -> bool:
+        return self.limit is not None and self.sent >= self.limit
+
+    def result(self) -> dict[str, int]:
+        return {**self.counts, "skipped": self.skipped, "errors": self.errors}
+
+    async def feed(self, records: list[Record]) -> None:
+        sink = self.sink
+        items = [
+            sink._prepare(i)
+            for i in extract_texts(
+                records, sources=self.sources, event_text_keys=sink.event_text_keys
+            )
+        ]
+        # The last text for a source wins, as in the live sink.
+        latest = list({(i.source_type, i.source_id): i for i in items}.values())
+        if self.have_table:
+            todo, stored = await sink._unembedded(latest)
+        else:
+            todo, stored = latest, set()
+        self.skipped += len(latest) - len(todo)
+        if self.limit is not None:
+            todo = todo[: max(0, self.limit - self.sent)]
+        self.sent += len(todo)
+        if self.dry_run:
+            for item in todo:
+                self.counts[item.source_type] += 1
+            return
+        for start in range(0, len(todo), sink.batch_size):
+            chunk = todo[start : start + sink.batch_size]
+            try:
+                vectors = await asyncio.wait_for(
+                    sink.embedder.embed([i.text for i in chunk]), sink.timeout
+                )
+                await sink._store(chunk, vectors, stored)
+            except Exception:
+                self.errors += len(chunk)
+                logger.warning(
+                    "Backfill failed to embed %d texts with %s",
+                    len(chunk),
+                    sink.embedder.model,
+                    exc_info=True,
+                )
+                continue
+            for item in chunk:
+                self.counts[item.source_type] += 1
+
+
+async def _has_table(engine: Any, name: str) -> bool:
+    async with engine.connect() as conn:
+        return await conn.run_sync(lambda sync: inspect(sync).has_table(name))
+
+
+async def _columns(engine: Any, name: str) -> set[str]:
+    async with engine.connect() as conn:
+        return await conn.run_sync(
+            lambda sync: {c["name"] for c in inspect(sync).get_columns(name)}
+        )
+
+
+async def _pages(
+    engine: Any,
+    table: Any,
+    columns: list[Any],
+    ts: Any,
+    where: Any,
+    since: datetime | None,
+    until: datetime | None,
+    page_size: int,
+) -> AsyncIterator[list[dict[str, Any]]]:
+    """Rows matching ``where``, oldest first, ``page_size`` at a time.
+
+    Keyset paging on (timestamp, id), so rows written during the run neither
+    shift the pages nor get read twice.
+    """
+    conditions = [where]
+    if since is not None:
+        conditions.append(ts >= since)
+    if until is not None:
+        conditions.append(ts < until)
+    last: tuple[Any, Any] | None = None
+    while True:
+        query = select(*columns).where(*conditions)
+        if last is not None:
+            query = query.where(tuple_(ts, table.c.id) > tuple_(*last))
+        query = query.order_by(ts, table.c.id).limit(page_size)
+        async with engine.connect() as conn:
+            rows = [dict(r) for r in (await conn.execute(query)).mappings()]
+        if not rows:
+            return
+        yield rows
+        if len(rows) < page_size:
+            return
+        last = (rows[-1][ts.name], rows[-1]["id"])
+
+
+async def _backfill_calls(run: _Run, since, until, page_size) -> None:
+    db = run.sink.database_sink
+    t = db.table
+    have = await _columns(db.engine, t.name)
+    if "outcome" in have:
+        # Rows from before the outcome column was added have it NULL and
+        # were errors exactly when they carry an error message.
+        where = or_(
+            t.c.outcome.in_(("error", "soft_error")),
+            and_(t.c.outcome.is_(None), t.c.error_message.is_not(None)),
+        )
+        columns = [t.c[c] for c in (*_CALL_COLUMNS, "outcome")]
+    else:
+        where = t.c.error_message.is_not(None)
+        columns = [t.c[c] for c in _CALL_COLUMNS]
+    async for rows in _pages(
+        db.engine, t, columns, t.c.started_at, where, since, until, page_size
+    ):
+        records: list[Record] = []
+        for row in rows:
+            row["outcome"] = row.get("outcome") or "error"
+            records.append(ToolCallRecord(**row))
+        await run.feed(records)
+        if run.done:
+            return
+
+
+async def _backfill_events(run: _Run, since, until, page_size) -> None:
+    db = run.sink.database_sink
+    e = db.events
+    kinds = []
+    if "feedback" in run.sources:
+        kinds.append(e.c.kind == FEEDBACK_KIND)
+    if "llm" in run.sources:
+        kinds.append(e.c.kind == LLM_KIND)
+    if "event" in run.sources:
+        # Includes llm.call: one without prompt or completion is a plain event.
+        kinds.append(e.c.kind != FEEDBACK_KIND)
+    columns = [e.c.id, e.c.kind, e.c.key, e.c.occurred_at, e.c.attrs]
+    async for rows in _pages(
+        db.engine, e, columns, e.c.occurred_at, or_(*kinds), since, until, page_size
+    ):
+        records: list[Record] = [
+            EventRecord(**{**row, "attrs": row["attrs"] or {}}) for row in rows
+        ]
+        await run.feed(records)
+        if run.done:
+            return
+
+
+async def _start(
+    sink: EmbeddingSink,
+    sources: Iterable[str] | None,
+    limit: int | None,
+    batch_size: int,
+    dry_run: bool,
+) -> _Run:
+    chosen = tuple(sink.sources if sources is None else sources)
+    unknown = set(chosen) - set(EMBEDDING_SOURCES)
+    if unknown:
+        raise ValueError(
+            f"unknown sources {sorted(unknown)}; choose from {EMBEDDING_SOURCES}"
+        )
+    if batch_size < 1:
+        raise ValueError(f"batch_size must be at least 1, got {batch_size!r}")
+    if limit is not None and limit < 0:
+        raise ValueError(f"limit must not be negative, got {limit!r}")
+    run = _Run(sink, sorted(chosen, key=EMBEDDING_SOURCES.index), limit, dry_run)
+    db = sink.database_sink
+    if not dry_run:
+        await db.ensure_embeddings()
+    run.have_table = await _has_table(db.engine, db.embeddings.name)
+    if not run.have_table and not dry_run:
+        raise RuntimeError(
+            f"{db.embeddings.name} does not exist; create it with a migration "
+            "or pass create_tables=True to the DatabaseSink"
+        )
+    return run
+
+
+async def backfill_embeddings(
+    embedding_sink: EmbeddingSink,
+    *,
+    sources: Iterable[str] | None = None,
+    since: datetime | None = None,
+    until: datetime | None = None,
+    limit: int | None = None,
+    batch_size: int = 500,
+    dry_run: bool = False,
+) -> dict[str, int]:
+    """Embed stored tool-call errors and events that have no embedding yet.
+
+    Reads the tables of ``embedding_sink.database_sink``:
+
+    - ``call_error``: calls with outcome ``error`` or ``soft_error``, and
+      calls with outcome NULL and an error message (rows written before the
+      outcome column existed).
+    - ``feedback``: ``feedback.submitted`` events.
+    - ``llm``: ``llm.call`` events with a prompt or completion.
+    - ``event``: other events with any of the sink's ``event_text_keys``.
+
+    Each text goes through the sink's extraction, redactor and ``max_chars``,
+    so it matches what the live sink makes of the same record. Texts already
+    stored with the same hash are skipped; a changed text replaces its row.
+
+    Args:
+        sources: which of the above; defaults to the sink's ``sources``.
+        since, until: only rows timestamped in [since, until). Naive
+            datetimes are taken as UTC.
+        limit: embed at most this many texts, oldest first. A later run
+            carries on, since what was embedded is then skipped.
+        batch_size: rows read per query. Texts are embedded in chunks of
+            the sink's ``batch_size``, each limited to its ``timeout``.
+        dry_run: count what would be embedded without calling the embedder
+            or writing anything.
+
+    Returns counts of texts embedded per source type, plus ``skipped``
+    (already embedded) and ``errors`` (texts whose embed or store failed;
+    logged, never raised). Raises ValueError for bad arguments and
+    RuntimeError when a table it needs does not exist.
+    """
+    run = await _start(embedding_sink, sources, limit, batch_size, dry_run)
+    db = embedding_sink.database_sink
+    since, until = _utc(since), _utc(until)
+    if "call_error" in run.sources:
+        if not await _has_table(db.engine, db.table.name):
+            raise RuntimeError(f"{db.table.name} does not exist")
+        if not run.done:
+            await _backfill_calls(run, since, until, batch_size)
+    if set(run.sources) & {"feedback", "event", "llm"}:
+        if not await _has_table(db.engine, db.events.name):
+            raise RuntimeError(f"{db.events.name} does not exist")
+        if not run.done:
+            await _backfill_events(run, since, until, batch_size)
+    result = run.result()
+    logger.info("Backfill %s: %s", "dry run" if dry_run else "done", result)
+    return result
+
+
+async def backfill_feedback(
+    embedding_sink: EmbeddingSink,
+    items: Iterable[tuple[str, str, str | None]],
+    *,
+    batch_size: int = 500,
+    dry_run: bool = False,
+) -> dict[str, int]:
+    """Embed feedback kept in the host's own tables, as (ref, title, description).
+
+    The text and source id are those of a ``feedback.submitted`` event with
+    key ``ref`` and those attrs, so feedback recorded later as an event
+    dedupes against these rows. Returns ``{"feedback", "skipped", "errors"}``
+    like ``backfill_embeddings``.
+    """
+    run = await _start(embedding_sink, ("feedback",), None, batch_size, dry_run)
+    now = datetime.now(UTC)
+    page: list[Record] = []
+    for ref, title, description in items:
+        page.append(
+            EventRecord(
+                kind=FEEDBACK_KIND,
+                occurred_at=now,
+                key=str(ref),
+                attrs={"title": title, "description": description},
+            )
+        )
+        if len(page) >= batch_size:
+            await run.feed(page)
+            page = []
+    if page:
+        await run.feed(page)
+    return run.result()
+
+
+__all__ = ["backfill_embeddings", "backfill_feedback"]

src/fastmcp_feedback/instrumentation/backfill/__main__.py

@@ -0,0 +1,5 @@
+import sys
+
+from .cli import main
+
+sys.exit(main())

src/fastmcp_feedback/instrumentation/backfill/cli.py

@@ -0,0 +1,143 @@
+"""python -m fastmcp_feedback.instrumentation.backfill
+
+Prints the counts as JSON. Exits 1 when any text failed to embed, 2 on a
+setup error (bad arguments, missing table, unreachable database).
+"""
+
+import argparse
+import asyncio
+import json
+import logging
+import os
+import sys
+from datetime import datetime
+
+from ..embeddings import DEFAULT_EVENT_TEXT_KEYS, EmbeddingSink, OpenAIEmbedder
+from ..storage import DEFAULT_TABLE_PREFIX, EMBEDDING_SOURCES, DatabaseSink
+from . import backfill_embeddings
+
+API_KEY_ENV = "FFB_EMBED_API_KEY"
+
+
+def _sources(value: str) -> tuple[str, ...]:
+    chosen = tuple(s.strip() for s in value.split(",") if s.strip())
+    unknown = set(chosen) - set(EMBEDDING_SOURCES)
+    if not chosen or unknown:
+        raise argparse.ArgumentTypeError(
+            f"choose from {','.join(EMBEDDING_SOURCES)}, comma separated"
+        )
+    return chosen
+
+
+def _when(value: str) -> datetime:
+    try:
+        return datetime.fromisoformat(value)
+    except ValueError as exc:
+        raise argparse.ArgumentTypeError(f"not an ISO 8601 time: {value!r}") from exc
+
+
+def build_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser(
+        prog="python -m fastmcp_feedback.instrumentation.backfill",
+        description=(
+            "Embed stored tool-call errors and events that have no embedding "
+            f"yet. The embedder's API key is read from ${API_KEY_ENV} (or the "
+            "variable named by --api-key-env)."
+        ),
+    )
+    parser.add_argument(
+        "--database-url",
+        required=True,
+        help="async SQLAlchemy URL, e.g. postgresql+asyncpg://... or sqlite+aiosqlite:///calls.db",
+    )
+    parser.add_argument(
+        "--embed-base-url",
+        help="OpenAI-compatible base URL up to the version, e.g. https://api.example.com/v1 "
+        "(required unless --dry-run)",
+    )
+    parser.add_argument("--api-key-env", default=API_KEY_ENV, metavar="NAME")
+    parser.add_argument("--model", default="mxbai-embed-large")
+    parser.add_argument("--dim", type=int, default=1024)
+    parser.add_argument("--prefix", default=DEFAULT_TABLE_PREFIX)
+    parser.add_argument(
+        "--sources",
+        type=_sources,
+        default=EMBEDDING_SOURCES,
+        help=f"comma separated, default {','.join(EMBEDDING_SOURCES)}",
+    )
+    parser.add_argument(
+        "--event-text-keys",
+        default=",".join(DEFAULT_EVENT_TEXT_KEYS),
+        help="attrs making up an event text, comma separated",
+    )
+    parser.add_argument("--since", type=_when, help="ISO 8601; naive means UTC")
+    parser.add_argument("--until", type=_when, help="ISO 8601, exclusive")
+    parser.add_argument("--limit", type=int, help="embed at most this many texts")
+    parser.add_argument("--batch-size", type=int, default=500, help="rows per query")
+    parser.add_argument("--max-chars", type=int, default=4000)
+    parser.add_argument(
+        "--create-tables",
+        action="store_true",
+        help="create the embeddings table (and vector extension) if missing",
+    )
+    parser.add_argument(
+        "--dry-run",
+        action="store_true",
+        help="count what would be embedded; call no embedder, write nothing",
+    )
+    parser.add_argument("-v", "--verbose", action="store_true")
+    return parser
+
+
+async def _run(args: argparse.Namespace) -> dict[str, int]:
+    embedder = OpenAIEmbedder(
+        args.embed_base_url or "http://embedder.invalid/v1",
+        api_key=os.environ.get(args.api_key_env) or None,
+        model=args.model,
+        dim=args.dim,
+    )
+    db = DatabaseSink(
+        args.database_url,
+        prefix=args.prefix,
+        create_tables=args.create_tables and not args.dry_run,
+        embedding_dim=args.dim,
+    )
+    try:
+        sink = EmbeddingSink(
+            embedder,
+            db,
+            sources=args.sources,
+            event_text_keys=[k for k in args.event_text_keys.split(",") if k],
+            max_chars=args.max_chars,
+        )
+        return await backfill_embeddings(
+            sink,
+            since=args.since,
+            until=args.until,
+            limit=args.limit,
+            batch_size=args.batch_size,
+            dry_run=args.dry_run,
+        )
+    finally:
+        await db.aclose()
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = build_parser()
+    args = parser.parse_args(argv)
+    if not args.dry_run and not args.embed_base_url:
+        parser.error("--embed-base-url is required unless --dry-run")
+    # The CLI owns logging; the package configures none. force: replace
+    # anything a host process (or a test runner) already set up.
+    logging.basicConfig(
+        level=logging.INFO if args.verbose else logging.WARNING,
+        format="%(levelname)s %(name)s: %(message)s",
+        force=True,
+    )
+    try:
+        counts = asyncio.run(_run(args))
+    except Exception as exc:
+        print(f"backfill failed: {type(exc).__name__}: {exc}", file=sys.stderr)
+        return 2
+    print(json.dumps({"dry_run": args.dry_run, **counts}))
+    return 1 if counts["errors"] else 0

src/fastmcp_feedback/instrumentation/classify.py

@@ -0,0 +1,165 @@
+"""Spotting tools that report failure as data instead of raising.
+
+A result classifier is ``(tool, result) -> str | None``. ``result`` is the
+recorded payload: the structured content when there is one, otherwise the
+content items. None means the call succeeded; a string marks it as a soft
+error and becomes the record's ``error_message`` (after redaction).
+
+A result the tool marked as an MCP error (``isError``) without raising reaches
+the classifier as a dict with ``"isError": True``, alongside the payload's own
+keys or with the payload under ``"content"``.
+"""
+
+from collections.abc import Callable, Iterable
+from typing import Any
+
+ResultClassifier = Callable[[str, Any], str | None]
+
+MESSAGE_KEYS = ("error", "message", "detail", "reason")
+ERROR_FLAG_KEYS = ("isError", "is_error")
+
+
+def lookup(result: dict, key: str) -> Any:
+    """``result[key]``, where ``key`` may be a dotted path into nested dicts.
+
+    A key present exactly as written wins, so a literal ``"a.b"`` key is
+    found before ``result["a"]["b"]``. Otherwise ``"snapshot.error"`` walks
+    ``result["snapshot"]["error"]``. A missing step, or a step that is not a
+    dict, gives None: the same as the key not being there. Never raises.
+    """
+    if key in result:
+        return result[key]
+    if "." not in key:
+        return None
+    value: Any = result
+    for part in key.split("."):
+        if not isinstance(value, dict) or part not in value:
+            return None
+        value = value[part]
+    return value
+
+
+def _message(
+    result: dict, depth: int = 0, keys: tuple[str, ...] = MESSAGE_KEYS
+) -> str | None:
+    for key in keys:
+        value = lookup(result, key)
+        if value is None or value == "":
+            continue
+        if isinstance(value, dict):
+            # {"error": {"code": 404, "message": "..."}}
+            if depth == 0 and (inner := _message(value, 1, keys)):
+                return inner
+            continue
+        if isinstance(value, list | tuple):
+            continue
+        return str(value)
+    return None
+
+
+def _content_text(content: Any) -> str | None:
+    if isinstance(content, str):
+        return content
+    if not isinstance(content, list | tuple):
+        return None
+    texts = [
+        item if isinstance(item, str) else item.get("text")
+        for item in content
+        if isinstance(item, str | dict)
+    ]
+    return " ".join(t for t in texts if t) or None
+
+
+def _describe(label: str, detail: str | None) -> str:
+    return f"{label}: {detail}" if detail else label
+
+
+def soft_error_classifier(
+    *,
+    statuses: Iterable[str] = ("error", "failed", "failure"),
+    status_keys: Iterable[str] = ("status", "state"),
+    flag_keys: Iterable[str] = ("ok", "success"),
+    extra_statuses: Iterable[str] = (),
+    error_keys: Iterable[str] = ("error",),
+    message_keys: Iterable[str] = MESSAGE_KEYS,
+) -> ResultClassifier:
+    """Build a classifier for dict results that describe their own failure.
+
+    A dict result is a soft error when any of ``flag_keys`` is exactly False,
+    when any of ``status_keys`` holds one of ``statuses`` or
+    ``extra_statuses`` (case-insensitive), or when the tool marked it
+    ``isError``. The message is the first of ``message_keys`` present
+    (``error``, ``message``, ``detail``, ``reason`` by default), e.g.
+    ``status=failed: disk full``. A dict found there is searched one level
+    down with the same keys, as in ``{"error": {"message": "..."}}``.
+
+    Failing those, it is a soft error when any of ``error_keys`` holds a
+    non-empty string, as in ``{"played": False, "error": "output stalled"}``,
+    with that string as the message (``error: output stalled``). None, empty
+    or blank strings, numbers, booleans, dicts and lists there do not count,
+    so ``{"error": None}`` and ``{"error": 0.02}`` stay ok. ``error_keys=()``
+    turns this off.
+
+    A result that says it succeeded, with any of ``flag_keys`` exactly True,
+    skips only that last check: ``{"ok": True, "error": "deprecated arg"}``
+    is ok, the string being a warning. A failing status, a False flag and
+    ``isError`` still flag it. Truthy non-bools such as ``1`` or ``"yes"``
+    are not an explicit success.
+
+    ``message_keys`` and ``error_keys`` accept dotted paths into nested
+    dicts: ``"snapshot.error"`` reads ``result["snapshot"]["error"]``. A key
+    that literally contains a dot is matched first; a missing step or one
+    that is not a dict counts as the key not being there. The message label
+    for an ``error_keys`` hit is the path as written. ``status_keys`` and
+    ``flag_keys`` are plain keys.
+
+    >>> classify = soft_error_classifier(extra_statuses=("unknown_target",))
+    >>> classify("render", {"status": "unknown_target", "error": "no such object"})
+    'status=unknown_target: no such object'
+    >>> classify("speak", {"played": False, "error": "output stalled"})
+    'error: output stalled'
+    >>> print(classify("speak", {"ok": True, "error": "deprecated arg"}))
+    None
+    >>> sitl = soft_error_classifier(
+    ...     status_keys=("status", "state", "reason"),
+    ...     extra_statuses=("died",),
+    ...     message_keys=("snapshot.error", "error", "message", "detail", "reason"),
+    ... )
+    >>> sitl("wait_until", {"reason": "died", "snapshot": {"error": "SITL exited"}})
+    'reason=died: SITL exited'
+    """
+    bad = frozenset(s.lower() for s in (*statuses, *extra_statuses))
+    status_keys = tuple(status_keys)
+    flag_keys = tuple(flag_keys)
+    error_keys = tuple(error_keys)
+    message_keys = tuple(message_keys)
+
+    def message(result: dict) -> str | None:
+        return _message(result, 0, message_keys)
+
+    def classify(tool: str, result: Any) -> str | None:
+        if not isinstance(result, dict):
+            return None
+        for key in status_keys:
+            value = result.get(key)
+            if isinstance(value, str) and value.lower() in bad:
+                return _describe(f"{key}={value}", message(result))
+        for key in flag_keys:
+            if key in result and result[key] is False:
+                return _describe(f"{key}=False", message(result))
+        for key in ERROR_FLAG_KEYS:
+            if result.get(key) is True:
+                detail = message(result) or _content_text(result.get("content"))
+                return _describe("isError", detail)
+        if any(result.get(key) is True for key in flag_keys):
+            return None
+        for key in error_keys:
+            value = lookup(result, key)
+            if isinstance(value, str) and value.strip():
+                return _describe(key, value.strip())
+        return None
+
+    return classify
+
+
+DEFAULT_RESULT_CLASSIFIER = soft_error_classifier()

src/fastmcp_feedback/instrumentation/constants.py

@@ -0,0 +1,12 @@
+"""Defaults shared by the storage and embedding modules.
+
+Kept apart from them so these import without the async database stack.
+"""
+
+DEFAULT_TABLE_PREFIX = "ffb_"
+DEFAULT_EMBEDDING_DIM = 1024
+# source_type values in {prefix}embeddings. Feedback rows survive pruning.
+EMBEDDING_SOURCES = ("feedback", "call_error", "event", "llm")
+FEEDBACK_SOURCE = "feedback"
+# Attribute keys whose text an EmbeddingSink embeds from events.
+DEFAULT_EVENT_TEXT_KEYS = ("error_excerpt", "error", "message", "reason")

src/fastmcp_feedback/instrumentation/correlation.py

@@ -0,0 +1,106 @@
+"""Linking feedback to the tool calls that came before it."""
+
+from collections.abc import Iterable
+from dataclasses import asdict, dataclass
+from datetime import UTC, datetime
+from typing import Any
+
+RULE_SESSION = "session"
+RULE_USER_WINDOW = "user_window"
+
+
+@dataclass
+class CallLink:
+    """A tool call linked to a piece of feedback, and why it matched."""
+
+    call_id: str
+    rule: str
+    tool: str
+    started_at: datetime
+    ok: bool
+    position: int = 0
+
+    def to_dict(self) -> dict[str, Any]:
+        data = asdict(self)
+        data["started_at"] = self.started_at.isoformat()
+        return data
+
+
+@dataclass
+class Candidate:
+    """The fields correlation needs, from a buffered record or a database row."""
+
+    id: str
+    tool: str
+    started_at: datetime
+    ok: bool
+    session_id: str | None
+    user_sub: str | None
+
+
+class ResolverContext:
+    """What an identity resolver receives when called during correlation.
+
+    Outside a tool call there is no MiddlewareContext, so this carries only the
+    ``fastmcp_context`` attribute, which is what resolvers normally read.
+    """
+
+    def __init__(self, fastmcp_context: Any):
+        self.fastmcp_context = fastmcp_context
+        self.message = None
+
+
+def as_utc(value: datetime) -> datetime:
+    # SQLite drops the timezone from DateTime(timezone=True) columns.
+    return value.replace(tzinfo=UTC) if value.tzinfo is None else value
+
+
+def select_calls(
+    candidates: Iterable[Candidate],
+    *,
+    session_id: str | None,
+    user_sub: str | None,
+    since: datetime,
+    limit: int,
+) -> list[CallLink]:
+    """Pick up to ``limit`` recent calls for a feedback item.
+
+    Calls from the same MCP session come first. If there are fewer than
+    ``limit``, the rest are filled with the same user's calls since ``since``,
+    which covers clients that open a new session per call (PATs, CI). The
+    result is in chronological order, numbered from 0.
+    """
+    unique: dict[str, Candidate] = {}
+    for c in candidates:
+        unique.setdefault(c.id, c)
+    newest_first = sorted(
+        unique.values(), key=lambda c: as_utc(c.started_at), reverse=True
+    )
+
+    chosen: list[tuple[Candidate, str]] = []
+    if session_id:
+        chosen += [
+            (c, RULE_SESSION) for c in newest_first if c.session_id == session_id
+        ][:limit]
+    if user_sub and len(chosen) < limit:
+        taken = {c.id for c, _ in chosen}
+        chosen += [
+            (c, RULE_USER_WINDOW)
+            for c in newest_first
+            if c.id not in taken
+            and c.user_sub == user_sub
+            and as_utc(c.started_at) >= since
+        ][: limit - len(chosen)]
+
+    chosen.sort(key=lambda pair: as_utc(pair[0].started_at))
+    return [
+        CallLink(
+            call_id=c.id,
+            rule=rule,
+            tool=c.tool,
+            started_at=as_utc(c.started_at),
+            ok=c.ok,
+            position=i,
+        )
+        for i, (c, rule) in enumerate(chosen)
+    ]

src/fastmcp_feedback/instrumentation/dispatch.py

@@ -0,0 +1,182 @@
+"""Background delivery of records to sinks, off the tool-call path."""
+
+import asyncio
+import contextlib
+import logging
+import threading
+from collections.abc import Callable, Sequence
+
+from .sinks import Record, Sink
+
+logger = logging.getLogger(__name__)
+
+
+class RecordDispatcher:
+    """Queue records and hand them to sinks from a background task.
+
+    ``submit`` never blocks and never raises: when the queue is full the record
+    is dropped and counted, so a slow or broken sink cannot slow down or fail
+    a tool call. Sink errors are logged and counted, never propagated.
+    """
+
+    def __init__(
+        self,
+        sinks: Sequence[Sink],
+        *,
+        max_queue: int = 1000,
+        batch_size: int = 100,
+        sink_timeout: float = 10.0,
+    ):
+        self.sinks = list(sinks)
+        self.max_queue = max_queue
+        self.batch_size = batch_size
+        self.sink_timeout = sink_timeout
+        self.dropped = 0
+        self.sink_errors = 0
+        self._queue: asyncio.Queue[Record] | None = None
+        self._task: asyncio.Task | None = None
+        self._loop: asyncio.AbstractEventLoop | None = None
+        # submit_threadsafe can drop from any thread.
+        self._drop_lock = threading.Lock()
+
+    def submit(self, record: Record) -> bool:
+        """Queue a record for delivery. Returns False if it was dropped."""
+        try:
+            loop = asyncio.get_running_loop()
+        except RuntimeError:
+            self._drop("no running event loop")
+            return False
+
+        self._bind(loop)
+        try:
+            self._queue.put_nowait(record)
+        except asyncio.QueueFull:
+            self._drop("queue full")
+            return False
+        return True
+
+    def bind_loop(self) -> None:
+        """Adopt the running loop, so other threads can submit before any record.
+
+        Called by the middleware as each tool call starts. Never raises.
+        """
+        with contextlib.suppress(Exception):
+            self._bind(asyncio.get_running_loop())
+
+    def _bind(self, loop: asyncio.AbstractEventLoop) -> None:
+        # A queue belongs to one loop; tests and some hosts run several.
+        if self._queue is None or self._loop is not loop:
+            self._loop = loop
+            self._queue = asyncio.Queue(maxsize=self.max_queue)
+            self._task = loop.create_task(self._run(self._queue))
+
+    def submit_threadsafe(
+        self,
+        record: Record,
+        on_queued: Callable[[Record], None] | None = None,
+    ) -> bool:
+        """``submit`` that may be called from any thread. Never blocks or raises.
+
+        On the loop the dispatcher runs on, or on any loop when it has none
+        running, this is ``submit``. From another thread the record is handed
+        to the dispatcher's loop with ``call_soon_threadsafe``; True then means
+        it was handed over, and a queue that fills before it lands still drops
+        and counts it. With no running loop anywhere the record is dropped.
+        ``on_queued(record)`` runs on the loop thread once the record is queued.
+        """
+        try:
+            try:
+                running = asyncio.get_running_loop()
+            except RuntimeError:
+                running = None
+            home = self._loop
+            home_alive = home is not None and home.is_running()
+            if running is not None and (not home_alive or home is running):
+                return self._submit_and_notify(record, on_queued)
+            if not home_alive:
+                self._drop("no running event loop")
+                return False
+            queue = self._queue
+            if queue is not None and queue.full():
+                self._drop("queue full")
+                return False
+            home.call_soon_threadsafe(self._submit_and_notify, record, on_queued)
+            return True
+        except Exception:
+            # call_soon_threadsafe raises if the loop closed after the check.
+            self._drop("event loop unavailable")
+            return False
+
+    def _submit_and_notify(
+        self, record: Record, on_queued: Callable[[Record], None] | None
+    ) -> bool:
+        if not self.submit(record):
+            return False
+        if on_queued is not None:
+            try:
+                on_queued(record)
+            except Exception:
+                logger.warning("on_queued callback failed", exc_info=True)
+        return True
+
+    def _drop(self, reason: str) -> None:
+        with self._drop_lock:
+            self.dropped += 1
+            dropped = self.dropped
+        if dropped == 1 or dropped % 1000 == 0:
+            logger.warning(
+                "Dropped instrumentation record (%s); %d dropped so far",
+                reason,
+                dropped,
+            )
+
+    async def _run(self, queue: asyncio.Queue) -> None:
+        while True:
+            batch = [await queue.get()]
+            while len(batch) < self.batch_size:
+                try:
+                    batch.append(queue.get_nowait())
+                except asyncio.QueueEmpty:
+                    break
+            try:
+                await self._deliver(batch)
+            finally:
+                for _ in batch:
+                    queue.task_done()
+
+    async def _deliver(self, batch: list[Record]) -> None:
+        for sink in self.sinks:
+            try:
+                await asyncio.wait_for(sink.write(batch), self.sink_timeout)
+            except Exception:
+                self.sink_errors += 1
+                logger.warning(
+                    "Sink %s failed to write %d records",
+                    type(sink).__name__,
+                    len(batch),
+                    exc_info=True,
+                )
+
+    async def flush(self) -> None:
+        """Wait until every queued record has been handed to the sinks."""
+        if self._queue is not None and self._loop is asyncio.get_running_loop():
+            await self._queue.join()
+
+    async def aclose(self) -> None:
+        """Flush, stop the background task and close the sinks."""
+        await self.flush()
+        if self._task is not None:
+            self._task.cancel()
+            with contextlib.suppress(asyncio.CancelledError, RuntimeError):
+                await self._task
+            self._task = None
+            self._queue = None
+        for sink in self.sinks:
+            close = getattr(sink, "aclose", None)
+            if close is not None:
+                try:
+                    await close()
+                except Exception:
+                    logger.warning(
+                        "Sink %s failed to close", type(sink).__name__, exc_info=True
+                    )

src/fastmcp_feedback/instrumentation/embeddings.py

@@ -0,0 +1,674 @@
+"""Embed feedback, tool errors, event text and LLM text for similarity search.
+
+EmbeddingSink sits next to a DatabaseSink. It picks text out of each batch,
+queues it on its own bounded queue and returns at once, so a slow embedding
+backend never holds up the dispatcher. A background task embeds and stores
+the vectors in ``{prefix}embeddings``.
+"""
+
+import asyncio
+import contextlib
+import hashlib
+import logging
+import math
+import operator
+import uuid
+from collections.abc import Iterable, Sequence
+from dataclasses import dataclass
+from datetime import UTC, datetime
+from typing import Any, Protocol, runtime_checkable
+
+from sqlalchemy import Float, and_, literal, not_, select, tuple_
+
+from .constants import DEFAULT_EVENT_TEXT_KEYS, EMBEDDING_SOURCES
+from .events import EventRecord
+from .payload import is_truncated
+from .record import ToolCallRecord
+from .redaction import Redactor
+from .sinks import Record
+from .storage import EmbeddingVector
+
+logger = logging.getLogger(__name__)
+
+
+@runtime_checkable
+class Embedder(Protocol):
+    """Turns texts into vectors of length ``dim``, one per text, in order."""
+
+    model: str
+    dim: int
+
+    async def embed(self, texts: list[str]) -> list[list[float]]: ...
+
+
+def _http_module() -> Any:
+    # FastMCP 2.x and 3.x depend on httpx, FastMCP 4 on its successor httpx2.
+    try:
+        import httpx
+
+        return httpx
+    except ImportError:
+        pass
+    try:
+        import httpx2
+
+        return httpx2
+    except ImportError as exc:
+        raise ImportError("OpenAIEmbedder needs httpx or httpx2") from exc
+
+
+class OpenAIEmbedder:
+    """An OpenAI-compatible ``POST {base_url}/embeddings`` endpoint.
+
+    Args:
+        base_url: up to and including the version, e.g.
+            ``https://api.example.com/v1``.
+        api_key: sent as ``Authorization: Bearer ...`` when given.
+        model: the ``model`` field of each request.
+        dim: expected vector length. A response with any other length raises
+            ValueError, since it cannot be stored or compared.
+        batch_size: texts per request.
+        timeout: seconds per request.
+        transport: passed to the HTTP client. For tests.
+    """
+
+    def __init__(
+        self,
+        base_url: str,
+        api_key: str | None = None,
+        model: str = "mxbai-embed-large",
+        dim: int = 1024,
+        batch_size: int = 32,
+        timeout: float = 30.0,
+        transport: Any = None,
+    ):
+        if batch_size < 1:
+            raise ValueError(f"batch_size must be at least 1, got {batch_size!r}")
+        self.base_url = base_url.rstrip("/")
+        self.api_key = api_key
+        self.model = model
+        self.dim = dim
+        self.batch_size = batch_size
+        self.timeout = timeout
+        self.transport = transport
+
+    async def embed(self, texts: list[str]) -> list[list[float]]:
+        if not texts:
+            return []
+        http = _http_module()
+        headers = {"Content-Type": "application/json"}
+        if self.api_key:
+            headers["Authorization"] = f"Bearer {self.api_key}"
+        vectors: list[list[float]] = []
+        kwargs: dict[str, Any] = {"timeout": self.timeout}
+        if self.transport is not None:
+            kwargs["transport"] = self.transport
+        async with http.AsyncClient(**kwargs) as client:
+            for start in range(0, len(texts), self.batch_size):
+                chunk = texts[start : start + self.batch_size]
+                response = await client.post(
+                    f"{self.base_url}/embeddings",
+                    json={"model": self.model, "input": chunk},
+                    headers=headers,
+                )
+                response.raise_for_status()
+                data = sorted(
+                    response.json()["data"], key=lambda item: item.get("index", 0)
+                )
+                if len(data) != len(chunk):
+                    raise ValueError(
+                        f"asked for {len(chunk)} embeddings, got {len(data)}"
+                    )
+                for item in data:
+                    vector = [float(v) for v in item["embedding"]]
+                    if len(vector) != self.dim:
+                        raise ValueError(
+                            f"{self.model} returned a {len(vector)}-dim vector, "
+                            f"expected {self.dim}"
+                        )
+                    vectors.append(vector)
+        return vectors
+
+
+@dataclass
+class EmbeddingText:
+    """One text waiting to be embedded, and where it came from."""
+
+    source_type: str
+    source_id: str
+    text: str
+
+    @property
+    def text_hash(self) -> str:
+        return hashlib.sha256(self.text.encode()).hexdigest()
+
+
+# Flattening stops adding items past this many characters; max_chars cuts
+# the result again later. Keeps a huge list from being joined in full.
+_FLAT_CHARS = 65536
+_FLAT_DEPTH = 32
+
+
+def _clean(value: Any, depth: int = 0) -> str | None:
+    """``value`` as stripped text, or None when there is none.
+
+    Lists and tuples become their items' texts, one per line. Dicts become
+    ``key: value`` lines sorted by key: PostgreSQL JSONB does not keep key
+    order, and the text has to come out the same when a backfill rebuilds it
+    from a stored row. Other values go through ``str()``.
+    """
+    if value is None:
+        return None
+    if is_truncated(value):
+        # A value over the middleware's max_payload_bytes: its start is all
+        # that was kept.
+        value = value.get("preview")
+    if isinstance(value, str):
+        text = value
+    elif isinstance(value, list | tuple | dict):
+        if depth >= _FLAT_DEPTH:
+            return None
+        if isinstance(value, dict):
+            pairs = sorted(value.items(), key=lambda kv: str(kv[0]))
+            parts = ((f"{k}: ", _clean(v, depth + 1)) for k, v in pairs)
+        else:
+            parts = (("", _clean(v, depth + 1)) for v in value)
+        lines: list[str] = []
+        size = 0
+        for label, part in parts:
+            if not part:
+                continue
+            lines.append(label + part)
+            size += len(lines[-1]) + 1
+            if size > _FLAT_CHARS:
+                break
+        text = "\n".join(lines)
+    else:
+        text = str(value)
+    text = text.strip()
+    return text or None
+
+
+def extract_texts(
+    records: Iterable[Record],
+    *,
+    sources: Iterable[str] = EMBEDDING_SOURCES,
+    event_text_keys: Sequence[str] = DEFAULT_EVENT_TEXT_KEYS,
+) -> list[EmbeddingText]:
+    """The texts worth embedding in a batch of records, unredacted and untruncated.
+
+    ``call_error``: calls with outcome ``error`` or ``soft_error``, as
+    ``"{tool}: {error_type}: {error_message}"``, keyed by the call id.
+    ``feedback``: ``feedback.submitted`` events, title and description,
+    keyed by the event's ``key`` (the feedback ref).
+    ``llm``: ``llm.call`` events with ``prompt`` or ``completion`` attrs.
+    ``event``: any other event with one of ``event_text_keys`` in its attrs,
+    those values joined by newlines, keyed by the event id. An ``llm.call``
+    without prompt or completion counts as a plain event, so a failed LLM
+    call's ``error`` is still embedded.
+
+    List and tuple values become one line per item, dicts ``key: value``
+    lines sorted by key, at any depth.
+    """
+    wanted = frozenset(sources)
+    out: list[EmbeddingText] = []
+    for record in records:
+        if isinstance(record, ToolCallRecord):
+            if "call_error" in wanted and record.outcome in ("error", "soft_error"):
+                parts = [record.tool, record.error_type, _clean(record.error_message)]
+                out.append(
+                    EmbeddingText(
+                        "call_error", record.id, ": ".join(p for p in parts if p)
+                    )
+                )
+            continue
+        if not isinstance(record, EventRecord):
+            continue
+        attrs = record.attrs or {}
+        if record.kind == "feedback.submitted":
+            if "feedback" in wanted:
+                body = "\n".join(
+                    t
+                    for t in (
+                        _clean(attrs.get("title")),
+                        _clean(attrs.get("description")),
+                    )
+                    if t
+                )
+                if body:
+                    out.append(EmbeddingText("feedback", record.key or record.id, body))
+            continue
+        if record.kind == "llm.call":
+            prompt, completion = (
+                _clean(attrs.get("prompt")),
+                _clean(attrs.get("completion")),
+            )
+            if prompt or completion:
+                if "llm" in wanted:
+                    lines = []
+                    if prompt:
+                        lines.append(f"prompt: {prompt}")
+                    if completion:
+                        lines.append(f"completion: {completion}")
+                    out.append(EmbeddingText("llm", record.id, "\n".join(lines)))
+                continue
+        if "event" in wanted:
+            values = [_clean(attrs.get(k)) for k in event_text_keys]
+            body = "\n".join(v for v in values if v)
+            if body:
+                out.append(EmbeddingText("event", record.id, body))
+    return out
+
+
+def _dot(a: Sequence[float], b: Sequence[float]) -> float:
+    sumprod = getattr(math, "sumprod", None)  # 3.12+
+    if sumprod is not None:
+        return sumprod(a, b)
+    return sum(map(operator.mul, a, b))
+
+
+def cosine_score(a: Sequence[float], b: Sequence[float]) -> float | None:
+    """1 - cosine distance, clamped to [0, 1]. None for a zero vector."""
+    na, nb = math.sqrt(_dot(a, a)), math.sqrt(_dot(b, b))
+    if not na or not nb:
+        return None
+    return _clamp(_dot(a, b) / (na * nb))
+
+
+def _clamp(score: float) -> float:
+    return min(1.0, max(0.0, score))
+
+
+class EmbeddingSink:
+    """Embed text from records and store the vectors through a DatabaseSink.
+
+    ``write`` only queues, so it returns at once whatever the embedder is
+    doing. A background task embeds up to ``batch_size`` texts at a time and
+    upserts them into ``{prefix}embeddings`` on ``database_sink.engine``. A
+    full queue drops the text and counts it in ``dropped``; embedder and
+    database failures are logged and counted in ``errors``, never raised.
+    A text whose (source_type, source_id, model) row already holds the same
+    text is not embedded again; a changed text replaces the row.
+
+    Text is redacted with ``redactor`` (the middleware's, when this sink is
+    passed to ``instrument``) and cut to ``max_chars`` before it is embedded
+    or stored.
+
+    Args:
+        embedder: anything with ``model``, ``dim`` and ``async embed(texts)``.
+        database_sink: the DatabaseSink whose engine and tables to use. Its
+            ``embedding_dim`` must equal ``embedder.dim``.
+        sources: which of ``feedback``, ``call_error``, ``event`` and ``llm``
+            to embed.
+        event_text_keys: attrs whose values make up an ``event`` text.
+        max_chars: longest text embedded.
+        max_queue: texts waiting to be embedded before new ones are dropped.
+        batch_size: texts per embed call.
+        timeout: seconds one embed call may take, and how long ``aclose``
+            waits for the queue to drain.
+        scan_limit: without pgvector, ``similar`` compares against the newest
+            this many rows.
+    """
+
+    def __init__(
+        self,
+        embedder: Embedder,
+        database_sink: Any,
+        *,
+        sources: Iterable[str] = EMBEDDING_SOURCES,
+        event_text_keys: Sequence[str] = DEFAULT_EVENT_TEXT_KEYS,
+        max_chars: int = 4000,
+        max_queue: int = 1000,
+        batch_size: int = 32,
+        timeout: float = 30.0,
+        scan_limit: int = 5000,
+        redactor: Redactor | None = None,
+    ):
+        self.sources = frozenset(sources)
+        unknown = self.sources - set(EMBEDDING_SOURCES)
+        if unknown:
+            raise ValueError(
+                f"unknown sources {sorted(unknown)}; choose from {EMBEDDING_SOURCES}"
+            )
+        if embedder.dim != database_sink.embedding_dim:
+            raise ValueError(
+                f"embedder {embedder.model!r} makes {embedder.dim}-dim vectors but "
+                f"the DatabaseSink's embeddings table holds "
+                f"{database_sink.embedding_dim}; pass embedding_dim={embedder.dim} "
+                "to DatabaseSink"
+            )
+        if max_chars < 1 or max_queue < 1 or batch_size < 1 or scan_limit < 1:
+            raise ValueError(
+                "max_chars, max_queue, batch_size and scan_limit must be positive"
+            )
+        self.embedder = embedder
+        self.database_sink = database_sink
+        self.table = database_sink.embeddings
+        self.event_text_keys = tuple(event_text_keys)
+        self.max_chars = max_chars
+        self.max_queue = max_queue
+        self.batch_size = batch_size
+        self.timeout = timeout
+        self.scan_limit = scan_limit
+        self.redactor = redactor
+        self._default_redactor = Redactor()
+        self.dropped = 0
+        self.errors = 0
+        self.embedded = 0
+        self.skipped = 0
+        self._queue: asyncio.Queue[EmbeddingText] | None = None
+        self._task: asyncio.Task | None = None
+        self._loop: asyncio.AbstractEventLoop | None = None
+        self._warned_scan = False
+
+    # Writing
+
+    async def write(self, records: Sequence[Record]) -> None:
+        try:
+            items = extract_texts(
+                records, sources=self.sources, event_text_keys=self.event_text_keys
+            )
+        except Exception:
+            self.errors += 1
+            logger.warning("Failed to extract texts to embed", exc_info=True)
+            return
+        for item in items:
+            self._enqueue(self._prepare(item))
+
+    def _prepare(self, item: EmbeddingText) -> EmbeddingText:
+        redactor = self.redactor or self._default_redactor
+        item.text = redactor.redact_text(item.text)[: self.max_chars]
+        return item
+
+    def _enqueue(self, item: EmbeddingText) -> None:
+        loop = asyncio.get_running_loop()
+        if self._queue is None or self._loop is not loop:
+            self._loop = loop
+            self._queue = asyncio.Queue(maxsize=self.max_queue)
+            self._task = loop.create_task(self._run(self._queue))
+        try:
+            self._queue.put_nowait(item)
+        except asyncio.QueueFull:
+            self.dropped += 1
+            if self.dropped == 1 or self.dropped % 1000 == 0:
+                logger.warning(
+                    "Embedding queue full; %d texts dropped so far", self.dropped
+                )
+
+    async def _run(self, queue: asyncio.Queue) -> None:
+        while True:
+            batch = [await queue.get()]
+            while len(batch) < self.batch_size:
+                try:
+                    batch.append(queue.get_nowait())
+                except asyncio.QueueEmpty:
+                    break
+            try:
+                await self._process(batch)
+            except Exception:
+                self.errors += 1
+                logger.warning(
+                    "Failed to embed %d texts with %s",
+                    len(batch),
+                    self.embedder.model,
+                    exc_info=True,
+                )
+            finally:
+                for _ in batch:
+                    queue.task_done()
+
+    async def _process(self, batch: list[EmbeddingText]) -> None:
+        # The last text for a source wins within a batch.
+        latest = {(i.source_type, i.source_id): i for i in batch}
+        db = self.database_sink
+        await db._ready()
+        await db.ensure_embeddings()
+        todo, stored = await self._unembedded(list(latest.values()))
+        self.skipped += len(batch) - len(todo)
+        if not todo:
+            return
+        vectors = await asyncio.wait_for(
+            self.embedder.embed([i.text for i in todo]), self.timeout
+        )
+        await self._store(todo, vectors, stored)
+        self.embedded += len(todo)
+
+    async def _unembedded(
+        self, items: list[EmbeddingText]
+    ) -> tuple[list[EmbeddingText], set[tuple[str, str]]]:
+        """The items whose stored row is missing or holds another text, and
+        the keys that have a row (to be replaced). Items must be unique by
+        (source_type, source_id)."""
+        if not items:
+            return [], set()
+        t = self.table
+        keys = [(i.source_type, i.source_id) for i in items]
+        async with self.database_sink.engine.connect() as conn:
+            rows = (
+                await conn.execute(
+                    select(t.c.source_type, t.c.source_id, t.c.text_hash).where(
+                        t.c.model == self.embedder.model,
+                        tuple_(t.c.source_type, t.c.source_id).in_(keys),
+                    )
+                )
+            ).all()
+        stored = {(r.source_type, r.source_id): r.text_hash for r in rows}
+        todo = [
+            i for i in items if stored.get((i.source_type, i.source_id)) != i.text_hash
+        ]
+        return todo, set(stored)
+
+    async def _store(
+        self,
+        todo: list[EmbeddingText],
+        vectors: list[list[float]],
+        replace: set[tuple[str, str]],
+    ) -> None:
+        db = self.database_sink
+        if len(vectors) != len(todo):
+            raise ValueError(
+                f"embedder returned {len(vectors)} vectors for {len(todo)}"
+            )
+        for vector in vectors:
+            if len(vector) != db.embedding_dim:
+                raise ValueError(
+                    f"embedder returned a {len(vector)}-dim vector, "
+                    f"expected {db.embedding_dim}"
+                )
+        now = datetime.now(UTC)
+        values = [
+            {
+                "id": str(uuid.uuid4()),
+                "source_type": i.source_type,
+                "source_id": i.source_id,
+                "model": self.embedder.model,
+                "dim": len(v),
+                "text_hash": i.text_hash,
+                "text": i.text,
+                "created_at": now,
+                "embedding": [float(x) for x in v],
+            }
+            for i, v in zip(todo, vectors, strict=True)
+        ]
+        await self._upsert(values, replace=replace)
+
+    async def _upsert(self, values: list[dict[str, Any]], replace: set) -> None:
+        t = self.table
+        engine = self.database_sink.engine
+        dialect = engine.dialect.name
+        changing = ("text_hash", "text", "created_at", "embedding", "dim")
+        if dialect in ("postgresql", "sqlite"):
+            if dialect == "postgresql":
+                from sqlalchemy.dialects.postgresql import insert
+            else:
+                from sqlalchemy.dialects.sqlite import insert
+            stmt = insert(t)
+            stmt = stmt.on_conflict_do_update(
+                index_elements=[t.c.source_type, t.c.source_id, t.c.model],
+                set_={c: stmt.excluded[c] for c in changing},
+            )
+            async with engine.begin() as conn:
+                await conn.execute(stmt, values)
+            return
+        async with engine.begin() as conn:
+            for row in values:
+                key = (row["source_type"], row["source_id"])
+                if key in replace:
+                    await conn.execute(
+                        t.update()
+                        .where(
+                            t.c.source_type == row["source_type"],
+                            t.c.source_id == row["source_id"],
+                            t.c.model == row["model"],
+                        )
+                        .values({c: row[c] for c in changing})
+                    )
+                else:
+                    await conn.execute(t.insert(), [row])
+
+    async def flush(self) -> None:
+        """Wait until every queued text has been embedded (or failed)."""
+        if self._queue is not None and self._loop is asyncio.get_running_loop():
+            await self._queue.join()
+
+    async def aclose(self) -> None:
+        """Drain the queue for up to ``timeout`` seconds, then stop.
+
+        Texts still queued after that are dropped and counted. Disposes the
+        DatabaseSink's engine again if it owns it, since the dispatcher may
+        have closed that sink first.
+        """
+        if self._queue is not None and self._loop is asyncio.get_running_loop():
+            try:
+                await asyncio.wait_for(self._queue.join(), self.timeout)
+            except TimeoutError:
+                left = self._queue.qsize()
+                self.dropped += left
+                logger.warning(
+                    "Embedding queue did not drain in %ss; %d texts dropped",
+                    self.timeout,
+                    left,
+                )
+        if self._task is not None:
+            self._task.cancel()
+            with contextlib.suppress(asyncio.CancelledError, RuntimeError):
+                await self._task
+            self._task = None
+            self._queue = None
+        if getattr(self.database_sink, "_owns_engine", False):
+            await self.database_sink.engine.dispose()
+
+    # Searching
+
+    async def similar(
+        self,
+        text: str,
+        *,
+        source_types: Iterable[str] | None = None,
+        k: int = 10,
+        min_score: float | None = None,
+    ) -> list[dict[str, Any]]:
+        """Stored texts closest to ``text``. Raises on failure; see the middleware."""
+        text = (self.redactor or self._default_redactor).redact_text(text)[
+            : self.max_chars
+        ]
+        [vector] = await asyncio.wait_for(self.embedder.embed([text]), self.timeout)
+        return await self.nearest(
+            vector, source_types=source_types, k=k, min_score=min_score
+        )
+
+    async def vector_for(self, source_type: str, source_id: str) -> list[float] | None:
+        """The stored vector for a source under this embedder's model, if any."""
+        t = self.table
+        async with self.database_sink.engine.connect() as conn:
+            row = (
+                await conn.execute(
+                    select(t.c.embedding).where(
+                        t.c.source_type == source_type,
+                        t.c.source_id == str(source_id),
+                        t.c.model == self.embedder.model,
+                    )
+                )
+            ).first()
+        return None if row is None else list(row.embedding)
+
+    async def nearest(
+        self,
+        vector: Sequence[float],
+        *,
+        source_types: Iterable[str] | None = None,
+        k: int = 10,
+        min_score: float | None = None,
+        exclude: tuple[str, str] | None = None,
+    ) -> list[dict[str, Any]]:
+        """Rows closest to ``vector`` by cosine, best first, as dicts with
+        ``source_type``, ``source_id``, ``text``, ``score`` and ``created_at``.
+
+        ``score`` is 1 - cosine distance, clamped to [0, 1]. Only rows made by
+        this embedder's model are compared. ``exclude`` is a
+        (source_type, source_id) left out of the results.
+        """
+        if k < 1:
+            return []
+        t = self.table
+        conditions = [t.c.model == self.embedder.model]
+        if source_types is not None:
+            conditions.append(t.c.source_type.in_(list(source_types)))
+        if exclude is not None:
+            conditions.append(
+                not_(and_(t.c.source_type == exclude[0], t.c.source_id == exclude[1]))
+            )
+        engine = self.database_sink.engine
+        cols = (t.c.source_type, t.c.source_id, t.c.text, t.c.created_at)
+        results: list[dict[str, Any]] = []
+        if engine.dialect.name == "postgresql":
+            distance = t.c.embedding.op("<=>", return_type=Float)(
+                literal(list(vector), type_=EmbeddingVector(len(vector)))
+            )
+            query = (
+                select(*cols, distance.label("distance"))
+                .where(*conditions)
+                .order_by(distance)
+                .limit(k)
+            )
+            async with engine.connect() as conn:
+                for row in (await conn.execute(query)).mappings():
+                    row = dict(row)
+                    distance_value = row.pop("distance")
+                    if distance_value is None or math.isnan(distance_value):
+                        continue
+                    row["score"] = _clamp(1.0 - distance_value)
+                    results.append(row)
+        else:
+            query = (
+                select(*cols, t.c.embedding)
+                .where(*conditions)
+                .order_by(t.c.created_at.desc())
+                .limit(self.scan_limit + 1)
+            )
+            async with engine.connect() as conn:
+                rows = [dict(r) for r in (await conn.execute(query)).mappings()]
+            if len(rows) > self.scan_limit:
+                rows = rows[: self.scan_limit]
+                if not self._warned_scan:
+                    self._warned_scan = True
+                    logger.info(
+                        "Similarity search without pgvector compares only the "
+                        "newest %d embeddings (scan_limit)",
+                        self.scan_limit,
+                    )
+            for row in rows:
+                score = cosine_score(vector, row.pop("embedding"))
+                if score is None:
+                    continue
+                row["score"] = score
+                results.append(row)
+            results.sort(key=lambda r: r["score"], reverse=True)
+            results = results[:k]
+        if min_score is not None:
+            results = [r for r in results if r["score"] >= min_score]
+        for row in results:
+            created = row["created_at"]
+            if created is not None and created.tzinfo is None:
+                row["created_at"] = created.replace(tzinfo=UTC)
+        return results

src/fastmcp_feedback/instrumentation/events.py

@@ -0,0 +1,95 @@
+"""Events: things worth recording that are not tool calls.
+
+A background job changing state, an LLM request made on a tool's behalf. Each
+event has a dotted ``kind``, an optional ``key`` to join on (a job id), and,
+when recorded while a tool call is running, that call's id.
+"""
+
+import math
+import uuid
+from dataclasses import asdict, dataclass, field
+from datetime import datetime
+from typing import Any, ClassVar
+
+# Column widths in {prefix}events. Longer values are refused rather than
+# truncated, since a cut key would silently stop joining.
+MAX_KIND_CHARS = 128
+MAX_KEY_CHARS = 255
+
+
+@dataclass
+class EventRecord:
+    """One event, as passed to sinks next to ``ToolCallRecord``.
+
+    ``call_id`` is the id of the tool call that was running when the event was
+    recorded, None outside a call. ``attrs`` is already redacted.
+    """
+
+    record_type: ClassVar[str] = "event"
+
+    kind: str
+    occurred_at: datetime
+    id: str = field(default_factory=lambda: str(uuid.uuid4()))
+    key: str | None = None
+    call_id: str | None = None
+    session_id: str | None = None
+    user_sub: str | None = None
+    caller_kind: str | None = None
+    client_id: str | None = None
+    server_version: str | None = None
+    attrs: dict[str, Any] = field(default_factory=dict)
+
+    def to_row(self) -> dict[str, Any]:
+        """Column values for the events table, with ``attrs`` made JSON-safe."""
+        data = asdict(self)
+        data["attrs"] = jsonable(data["attrs"])
+        return data
+
+    def to_dict(self) -> dict[str, Any]:
+        """JSON-friendly form, with the timestamp as ISO 8601."""
+        data = self.to_row()
+        data["occurred_at"] = self.occurred_at.isoformat()
+        return data
+
+
+@dataclass
+class CallScope:
+    """The tool call in progress, visible to ``record_event`` through a ContextVar.
+
+    Tasks started inside a tool inherit a copy of the context and outlive the
+    call, so the scope is switched off when the call ends instead of relying
+    on the ContextVar reset alone.
+
+    ``user_sub``, ``caller_kind`` and ``client_id`` are the call's identity,
+    resolved before the tool runs, so events recorded inside it carry them.
+    """
+
+    id: str
+    session_id: str | None
+    active: bool = True
+    events: int = 0
+    user_sub: str | None = None
+    caller_kind: str | None = None
+    client_id: str | None = None
+
+
+def jsonable(value: Any, depth: int = 0) -> Any:
+    """A copy of ``value`` that any JSON column accepts.
+
+    Non-finite floats (a diverged residual) become strings, since Postgres
+    JSONB rejects NaN and one bad row would fail the whole batch. Other
+    unknown types become ``str(value)``.
+    """
+    if depth > 32:
+        return "[TRUNCATED]"
+    if value is None or isinstance(value, bool | int | str):
+        return value
+    if isinstance(value, float):
+        return value if math.isfinite(value) else str(value)
+    if isinstance(value, dict):
+        return {str(k): jsonable(v, depth + 1) for k, v in value.items()}
+    if isinstance(value, list | tuple | set | frozenset):
+        return [jsonable(v, depth + 1) for v in value]
+    if isinstance(value, datetime):
+        return value.isoformat()
+    return str(value)

src/fastmcp_feedback/instrumentation/middleware.py

@@ -0,0 +1,952 @@
+"""FastMCP middleware that records every tool call, and events you report."""
+
+import asyncio
+import contextlib
+import contextvars
+import inspect
+import logging
+import os
+import random as _random
+import sys
+import time
+import uuid
+from collections import deque
+from collections.abc import Awaitable, Callable, Iterable, Mapping, Sequence
+from datetime import UTC, datetime, timedelta
+from typing import TYPE_CHECKING, Any, NamedTuple
+
+from fastmcp import FastMCP
+from fastmcp.server.middleware import Middleware, MiddlewareContext
+
+from .classify import DEFAULT_RESULT_CLASSIFIER, ResultClassifier
+from .correlation import (
+    CallLink,
+    Candidate,
+    ResolverContext,
+    as_utc,
+    select_calls,
+)
+from .dispatch import RecordDispatcher
+from .events import (
+    MAX_KEY_CHARS,
+    MAX_KIND_CHARS,
+    CallScope,
+    EventRecord,
+    jsonable,
+)
+from .payload import DEFAULT_MAX_PAYLOAD_BYTES, cap, cap_attrs, json_size
+from .record import ToolCallRecord
+from .redaction import Redactor
+from .sinks import JsonLinesSink, Sink
+
+if TYPE_CHECKING:
+    from .embeddings import EmbeddingSink
+    from .storage import DatabaseSink
+
+logger = logging.getLogger(__name__)
+
+MODES = ("off", "meta", "full")
+MODE_ENV_VAR = "FEEDBACK_INSTRUMENTATION_MODE"
+
+IdentityResolver = Callable[
+    [MiddlewareContext], dict[str, Any] | Awaitable[dict[str, Any]] | None
+]
+Enricher = Callable[
+    [str, Any, Any, MiddlewareContext],
+    dict[str, Any] | Awaitable[dict[str, Any]] | None,
+]
+
+# Keys an identity resolver can return that get their own columns.
+_IDENTITY_COLUMNS = ("user_sub", "caller_kind", "client_id")
+
+
+def _attr(obj: Any, name: str) -> Any:
+    try:
+        value = getattr(obj, name, None)
+    except Exception:
+        return None
+    return str(value) if value is not None else None
+
+
+# stdio serves exactly one client per process, so the process is the session.
+_STDIO_SESSION = f"stdio:{os.getpid()}:{uuid.uuid4().hex[:8]}"
+
+
+def session_key(ctx: Any) -> str | None:
+    """A per-client key that stays the same across that client's calls.
+
+    Clients on MCP protocol 2026-07-28 (Claude Code, FastMCP 4's Client) do
+    not open sessions, and FastMCP then generates a new ``ctx.session_id`` for
+    every request. So stable signals come first: the HTTP ``mcp-session-id``
+    header (older protocol clients), then one key per process for stdio, then
+    ``ctx.session_id``. With a stateless HTTP client there is no session, and
+    correlation relies on the same-user rule.
+    """
+    if ctx is None:
+        return None
+    try:
+        from fastmcp.server.dependencies import get_http_headers
+
+        header = (get_http_headers(include_all=True) or {}).get("mcp-session-id")
+        if header:
+            return header
+    except Exception:
+        pass
+    if _attr(ctx, "transport") == "stdio":
+        return _STDIO_SESSION
+    return _attr(ctx, "session_id")
+
+
+def _tool_name(context: MiddlewareContext) -> str:
+    return getattr(context.message, "name", None) or "unknown"
+
+
+def _result_payload(result: Any) -> Any:
+    structured = getattr(result, "structured_content", None)
+    if structured is not None:
+        return structured
+    content = getattr(result, "content", None)
+    if content is not None:
+        return [
+            getattr(item, "text", None) or {"type": getattr(item, "type", None)}
+            for item in content
+        ]
+    return result
+
+
+class InstrumentationMiddleware(Middleware):
+    """Record every tool call without ever slowing or breaking it.
+
+    Modes:
+        ``off``: pass calls straight through.
+        ``meta`` (default): tool, timing, outcome, identity and payload sizes.
+        ``full``: also the arguments and result, redacted.
+
+    The mode defaults to the ``FEEDBACK_INSTRUMENTATION_MODE`` environment
+    variable, then ``meta``. Records go to the sinks from a background task
+    through a bounded queue; when it fills, records are dropped, not waited on.
+
+    Args:
+        sinks: where records go. Defaults to JSON lines on stderr.
+        mode: see above.
+        redactor: secret redaction for args, results, error text and extras.
+        meta_only_tools: tools that are never recorded above ``meta``.
+        identity_resolver: ``(context) -> dict`` returning ``user_sub``,
+            ``caller_kind`` and ``client_id`` (stored as columns) plus any
+            other keys (stored in ``identity``). May be async. Runs before
+            the tool, so events recorded during the call get that identity;
+            it also runs for calls that sampling later drops, and an async
+            one can delay the tool by up to ``hook_timeout``; keep it cheap.
+            When that first answer is empty (nothing, or only None values,
+            including a run that failed or timed out) or lacks any of
+            ``late_identity_keys``, it runs again after the tool, alongside
+            the enricher, and the call's own record takes the second
+            answer's values where the first had none. Any other answer means
+            one run, even without all three columns.
+        late_identity_keys: identity keys that may only exist once the tool
+            has run, such as an id a registration or login tool creates. A
+            first answer without one of them gets the second run. Empty by
+            default.
+        enricher: ``(tool, args, result, context) -> dict`` of extra fields,
+            stored in ``extra``. A ``server_version`` key fills that column.
+            May be async.
+        server_version: default for the ``server_version`` column.
+        hook_timeout: seconds an async hook may take before it is skipped.
+        recent_calls: how many recent records to keep in memory for
+            correlation, including ones still waiting to reach the sinks.
+        correlation_timeout: seconds a database lookup during correlation may
+            take before it is skipped.
+        result_classifier: ``(tool, result) -> str | None`` run on results
+            of calls that did not raise. A string marks the call as a soft
+            error (``outcome="soft_error"``, ``ok=False``) and becomes the
+            error message. Defaults to ``DEFAULT_RESULT_CLASSIFIER``; None
+            turns it off. If it raises, the call is recorded as ok.
+        exclude_tools: tools that are never recorded, nor kept for
+            correlation. The calls themselves are untouched.
+        sample_rates: tool name to the fraction of its ok calls recorded, in
+            (0, 1]. Failures (``error`` and ``soft_error``) are always
+            recorded. Sampled-in ok rows carry ``sample_rate``; calls
+            sampled out are not kept for correlation either.
+        random: ``() -> float`` in [0, 1) deciding sampling; a call is kept
+            when it returns less than the tool's rate. For tests.
+        recent_events: how many recent events to keep in memory for
+            ``events_for``, including ones still waiting to reach the sinks.
+        capture_llm_text: store ``prompt`` and ``completion`` given to
+            ``record_llm_call``. Off by default, since chat text can hold
+            anything a user typed; when off they are discarded, including
+            ``prompt``/``completion`` keys passed in its ``attrs``.
+        max_llm_text_chars: longest prompt or completion kept. Defaults to
+            ``8 * max_error_chars`` (4000).
+        max_payload_bytes: largest stored arguments, result (mode ``full``)
+            or event ``attrs``, in bytes of JSON; None for no limit. Larger
+            ones are stored as ``{"_truncated": true, "size": ..., "preview":
+            ...}`` markers, after redaction; for attrs, only the largest
+            values are replaced. See ``fastmcp_feedback.instrumentation.payload``.
+
+    Exclusion and sampling apply to tool calls only; events are always
+    recorded. A sampled tool's call is kept whenever an event was recorded
+    during it, so the event's ``call_id`` always has a row.
+    """
+
+    def __init__(
+        self,
+        sinks: Sequence[Sink] | None = None,
+        *,
+        mode: str | None = None,
+        redactor: Redactor | None = None,
+        meta_only_tools: Iterable[str] = (),
+        identity_resolver: IdentityResolver | None = None,
+        late_identity_keys: Iterable[str] = (),
+        enricher: Enricher | None = None,
+        server_version: str | None = None,
+        hook_timeout: float = 0.25,
+        max_queue: int = 1000,
+        batch_size: int = 100,
+        sink_timeout: float = 10.0,
+        max_error_chars: int = 500,
+        recent_calls: int = 2000,
+        correlation_timeout: float = 1.0,
+        result_classifier: ResultClassifier | None = DEFAULT_RESULT_CLASSIFIER,
+        exclude_tools: Iterable[str] = (),
+        sample_rates: Mapping[str, float] | None = None,
+        random: Callable[[], float] = _random.random,
+        recent_events: int = 2000,
+        capture_llm_text: bool = False,
+        max_llm_text_chars: int | None = None,
+        max_payload_bytes: int | None = DEFAULT_MAX_PAYLOAD_BYTES,
+    ):
+        mode = (mode or os.getenv(MODE_ENV_VAR) or "meta").lower()
+        if mode not in MODES:
+            raise ValueError(f"mode must be one of {MODES}, got {mode!r}")
+        self.mode = mode
+        self.redactor = redactor or Redactor()
+        self.meta_only_tools = frozenset(meta_only_tools)
+        self.identity_resolver = identity_resolver
+        self.late_identity_keys = tuple(late_identity_keys)
+        self.enricher = enricher
+        self.server_version = server_version
+        self.hook_timeout = hook_timeout
+        self.max_error_chars = max_error_chars
+        self.correlation_timeout = correlation_timeout
+        self.result_classifier = result_classifier
+        self.exclude_tools = frozenset(exclude_tools)
+        self.sample_rates: dict[str, float] = {}
+        for tool, rate in (sample_rates or {}).items():
+            rate = float(rate)
+            if not 0 < rate <= 1:  # also rejects NaN
+                raise ValueError(
+                    f"sample rate for {tool!r} must be in (0, 1], got {rate!r}"
+                )
+            self.sample_rates[tool] = rate
+        self.random = random
+        self.recent: deque[ToolCallRecord] = deque(maxlen=recent_calls)
+        self.recent_events: deque[EventRecord] = deque(maxlen=recent_events)
+        # One per middleware, so events only link to calls this one records.
+        self._call_scope: contextvars.ContextVar[CallScope | None] = (
+            contextvars.ContextVar(f"ffb_call_scope_{id(self):x}", default=None)
+        )
+        self.capture_llm_text = capture_llm_text
+        if max_payload_bytes is not None and (
+            isinstance(max_payload_bytes, bool)
+            or not isinstance(max_payload_bytes, int)
+            or max_payload_bytes <= 0
+        ):
+            raise ValueError(
+                f"max_payload_bytes must be a positive int or None, "
+                f"got {max_payload_bytes!r}"
+            )
+        self.max_payload_bytes = max_payload_bytes
+        self.max_llm_text_chars = (
+            max_llm_text_chars
+            if max_llm_text_chars is not None
+            else 8 * max_error_chars
+        )
+        sinks = list(sinks) if sinks is not None else [JsonLinesSink()]
+        for sink in sinks:
+            # Embedded text gets this middleware's redaction rules too.
+            if _is_sink(sink, "embeddings", "EmbeddingSink") and sink.redactor is None:
+                sink.redactor = self.redactor
+        self.dispatcher = RecordDispatcher(
+            sinks,
+            max_queue=max_queue,
+            batch_size=batch_size,
+            sink_timeout=sink_timeout,
+        )
+
+    async def on_call_tool(self, context: MiddlewareContext, call_next):
+        if self.mode == "off":
+            return await call_next(context)
+        # Sync tools run in worker threads; their events need the loop known.
+        self.dispatcher.bind_loop()
+        if _tool_name(context) in self.exclude_tools:
+            return await call_next(context)
+
+        # Resolved before the tool runs, so events recorded inside it carry
+        # the caller; the call's own record reuses it.
+        who = await self._resolve_identity(context)
+        result = None
+        error: BaseException | None = None
+        scope = token = None
+        try:
+            # The record id exists before the tool runs, so events recorded
+            # inside it carry the id the stored call row will have.
+            scope = CallScope(
+                id=str(uuid.uuid4()),
+                session_id=session_key(context.fastmcp_context),
+                user_sub=who.column("user_sub"),
+                caller_kind=who.column("caller_kind"),
+                client_id=who.column("client_id"),
+            )
+            token = self._call_scope.set(scope)
+        except Exception:
+            logger.warning("Failed to open call scope", exc_info=True)
+        started_at = datetime.now(UTC)
+        start = time.perf_counter()
+        try:
+            result = await call_next(context)
+            return result
+        except BaseException as exc:
+            error = exc
+            raise
+        finally:
+            duration_ms = (time.perf_counter() - start) * 1000
+            if scope is not None:
+                scope.active = False
+            if token is not None:
+                # ValueError when finishing in another context (a task group).
+                with contextlib.suppress(ValueError):
+                    self._call_scope.reset(token)
+            try:
+                await self._record(
+                    context, started_at, duration_ms, result, error, scope, who
+                )
+            except Exception:
+                logger.warning("Failed to record tool call", exc_info=True)
+
+    async def _record(
+        self,
+        context: MiddlewareContext,
+        started_at: datetime,
+        duration_ms: float,
+        result: Any,
+        error: BaseException | None,
+        scope: CallScope | None,
+        who: "_Identity",
+    ) -> None:
+        tool = _tool_name(context)
+        payload = _result_payload(result) if result is not None else None
+        soft = None
+        if error is None and self.result_classifier is not None and payload is not None:
+            soft = self._classify(tool, result, payload)
+        rate = self.sample_rates.get(tool)
+        # Failures are always kept, and their rows carry no sample_rate. So are
+        # calls that recorded events, which would otherwise point at nothing.
+        if rate is not None and (
+            error is not None or soft is not None or (scope and scope.events)
+        ):
+            rate = None
+        elif rate is not None and not self.random() < rate:
+            return
+        record = await self._build_record(
+            context, started_at, duration_ms, payload, error, soft, rate, who
+        )
+        if scope is not None:
+            record.id = scope.id
+        self.recent.append(record)
+        self.dispatcher.submit(record)
+
+    async def _resolve_identity(self, context: MiddlewareContext) -> "_Identity":
+        """Run the identity resolver once. Never raises.
+
+        Returns the redacted result split into the three columns and the
+        rest, plus the FastMCP context's ``client_id`` as the fallback for a
+        resolver that gives none.
+        """
+        fallback = None
+        try:
+            fallback = _attr(context.fastmcp_context, "client_id")
+            identity = await self._call_hook(self.identity_resolver, context)
+            identity = self.redactor.redact(identity)
+            columns = {k: identity.pop(k) for k in _IDENTITY_COLUMNS if k in identity}
+            return _Identity(columns, identity, fallback)
+        except Exception:
+            logger.warning("Failed to resolve identity", exc_info=True)
+            return _Identity({}, {}, fallback)
+
+    def _identity_incomplete(self, who: "_Identity") -> bool:
+        """Whether the resolver's first answer lacks something it may know later."""
+        if self.identity_resolver is None:
+            return False
+        answered = any(
+            v is not None for v in (*who.columns.values(), *who.rest.values())
+        )
+        return not answered or any(
+            who.rest.get(k) is None and who.columns.get(k) is None
+            for k in self.late_identity_keys
+        )
+
+    async def _call_hook(self, hook: Callable | None, *args: Any) -> dict[str, Any]:
+        if hook is None:
+            return {}
+        try:
+            out = hook(*args)
+            if inspect.isawaitable(out):
+                out = await asyncio.wait_for(out, self.hook_timeout)
+            return dict(out) if out else {}
+        except Exception:
+            logger.warning("Instrumentation hook %r failed", hook, exc_info=True)
+            return {}
+
+    def _classify(self, tool: str, result: Any, payload: Any) -> str | None:
+        if getattr(result, "is_error", False) is True:
+            # FastMCP 3.4+ keeps isError on the ToolResult, not in the payload.
+            if isinstance(payload, dict):
+                payload = {**payload, "isError": True}
+            else:
+                payload = {"isError": True, "content": payload}
+        try:
+            message = self.result_classifier(tool, payload)
+        except Exception:
+            logger.warning(
+                "Result classifier %r failed", self.result_classifier, exc_info=True
+            )
+            return None
+        return None if message is None else str(message)
+
+    async def _build_record(
+        self,
+        context: MiddlewareContext,
+        started_at: datetime,
+        duration_ms: float,
+        payload: Any,
+        error: BaseException | None,
+        soft: str | None,
+        sample_rate: float | None,
+        who: "_Identity",
+    ) -> ToolCallRecord:
+        tool = _tool_name(context)
+        args = getattr(context.message, "arguments", None) or {}
+        ctx = context.fastmcp_context
+
+        enrich = self._call_hook(self.enricher, tool, args, payload, context)
+        if self._identity_incomplete(who):
+            # A tool can create the identity it runs under (a registration,
+            # a login). Ask again, concurrently with the enricher so the
+            # record is not built any later than the slower of the two.
+            later, extra = await asyncio.gather(self._resolve_identity(context), enrich)
+            who = who.filled_from(later)
+        else:
+            extra = await enrich
+        identity = dict(who.rest)
+        columns = {k: who.column(k) for k in _IDENTITY_COLUMNS}
+        extra = self.redactor.redact(extra)
+        server_version = extra.pop("server_version", None) or self.server_version
+
+        mode = "meta" if tool in self.meta_only_tools else self.mode
+        full = mode == "full"
+
+        outcome = "ok"
+        error_type = error_message = None
+        if error is not None:
+            # FastMCP wraps tool exceptions in ToolError; report the original.
+            cause = error.__cause__ or error
+            outcome = "error"
+            error_type = type(cause).__name__
+            error_message = self.redactor.redact_text(str(cause))[
+                : self.max_error_chars
+            ]
+        elif soft is not None:
+            outcome = "soft_error"
+            error_type = "SoftError"
+            error_message = (
+                self.redactor.redact_text(soft)[: self.max_error_chars] or None
+            )
+
+        # Measured once: the size columns and the payload limit share it.
+        args_size = json_size(args)
+        result_size = json_size(payload) if payload is not None else None
+        return ToolCallRecord(
+            tool=tool,
+            started_at=started_at,
+            duration_ms=duration_ms,
+            ok=outcome == "ok",
+            outcome=outcome,
+            mode=mode,
+            error_type=error_type,
+            error_message=error_message,
+            session_id=session_key(ctx),
+            request_id=_attr(ctx, "request_id"),
+            client_id=columns.get("client_id"),
+            user_sub=columns.get("user_sub"),
+            caller_kind=columns.get("caller_kind"),
+            identity=identity,
+            server_version=server_version,
+            args_size=args_size,
+            result_size=result_size,
+            args=cap(self.redactor.redact(args), args_size, self.max_payload_bytes)
+            if full
+            else None,
+            result=cap(
+                self.redactor.redact(payload), result_size, self.max_payload_bytes
+            )
+            if full and payload is not None
+            else None,
+            extra=extra,
+            sample_rate=sample_rate,
+        )
+
+    def record_event(
+        self,
+        kind: str,
+        *,
+        key: Any = None,
+        attrs: Mapping[str, Any] | None = None,
+        user_sub: str | None = None,
+        call_id: str | None = None,
+        caller_kind: str | None = None,
+        client_id: str | None = None,
+    ) -> bool:
+        """Record something that is not a tool call. Never raises or blocks.
+
+        Safe from any thread. Inside a tool call the event gets that call's
+        id, session, and the ``user_sub``, ``caller_kind`` and ``client_id``
+        the identity resolver gave the call; each of those given here wins.
+        Outside a call (including a task the call started that is still
+        running after it returned) only what is passed is stored. ``attrs`` is redacted like
+        call arguments and made JSON-safe. ``kind`` must be a non-empty string
+        of at most 128 characters and ``key`` at most 255 once made a string.
+        A ``key`` used for joining must stay unique for the retention period
+        and across restarts, so not a per-boot counter: use a UUID or a
+        startup token plus a counter.
+
+        Returns False when the event was not recorded: mode ``off``, an invalid
+        ``kind``, ``key`` or ``attrs``, a full queue, or no event loop to hand
+        it to (called from a thread before anything was recorded on the
+        server's loop). From another thread, True means handed to the loop.
+        """
+        try:
+            if self.mode == "off":
+                return False
+            if not isinstance(kind, str) or not kind.strip():
+                logger.warning("record_event needs a non-empty str kind, got %r", kind)
+                return False
+            if len(kind) > MAX_KIND_CHARS:
+                logger.warning(
+                    "Event kind longer than %d chars: %r", MAX_KIND_CHARS, kind
+                )
+                return False
+            if key is not None:
+                key = str(key)
+                if len(key) > MAX_KEY_CHARS:
+                    logger.warning("Event key longer than %d chars", MAX_KEY_CHARS)
+                    return False
+            if attrs is not None and not isinstance(attrs, Mapping):
+                logger.warning("Event attrs must be a mapping, got %s", type(attrs))
+                return False
+            session_id = None
+            scope = self._call_scope.get()
+            if scope is not None and scope.active:
+                scope.events += 1
+                session_id = scope.session_id
+                if call_id is None:
+                    call_id = scope.id
+                if user_sub is None:
+                    user_sub = scope.user_sub
+                if caller_kind is None:
+                    caller_kind = scope.caller_kind
+                if client_id is None:
+                    client_id = scope.client_id
+            record = EventRecord(
+                kind=kind,
+                occurred_at=datetime.now(UTC),
+                key=key,
+                call_id=None if call_id is None else str(call_id),
+                session_id=session_id,
+                user_sub=None if user_sub is None else str(user_sub),
+                caller_kind=None if caller_kind is None else str(caller_kind),
+                client_id=None if client_id is None else str(client_id),
+                server_version=self.server_version,
+                attrs=cap_attrs(
+                    jsonable(self.redactor.redact(dict(attrs or {}))),
+                    self.max_payload_bytes,
+                ),
+            )
+            return self.dispatcher.submit_threadsafe(record, self.recent_events.append)
+        except Exception:
+            logger.warning("Failed to record event %r", kind, exc_info=True)
+            return False
+
+    def record_llm_call(
+        self,
+        *,
+        model: str,
+        provider: str | None = None,
+        duration_ms: float | None = None,
+        input_tokens: int | None = None,
+        output_tokens: int | None = None,
+        ok: bool | None = None,
+        error: str | BaseException | None = None,
+        key: Any = None,
+        attrs: Mapping[str, Any] | None = None,
+        prompt: str | None = None,
+        completion: str | None = None,
+    ) -> bool:
+        """Record one LLM request as an ``llm.call`` event. Never raises.
+
+        Attributes: ``model``, ``provider``, ``duration_ms``, ``input_tokens``,
+        ``output_tokens`` (each only when given), ``ok``, and on failure
+        ``error`` (redacted, truncated to ``max_error_chars``) plus
+        ``error_type`` when ``error`` is an exception. ``ok`` defaults to
+        ``error is None``. Extra ``attrs`` are kept, but these names win.
+
+        ``prompt`` and ``completion`` are stored, redacted and truncated to
+        ``max_llm_text_chars``, only with ``capture_llm_text=True``;
+        otherwise they are discarded.
+        """
+        try:
+            fields: dict[str, Any] = dict(attrs or {})
+            fields.pop("prompt", None)
+            fields.pop("completion", None)
+            if self.capture_llm_text:
+                for name, value in (("prompt", prompt), ("completion", completion)):
+                    if value is None and attrs is not None:
+                        value = attrs.get(name)
+                    if value is not None:
+                        text = self.redactor.redact_text(str(value))
+                        fields[name] = text[: self.max_llm_text_chars]
+            fields["model"] = None if model is None else str(model)
+            for name, value in (
+                ("provider", provider),
+                ("duration_ms", duration_ms),
+                ("input_tokens", input_tokens),
+                ("output_tokens", output_tokens),
+            ):
+                if value is not None:
+                    fields[name] = value
+            fields["ok"] = (error is None) if ok is None else bool(ok)
+            if error is not None:
+                if isinstance(error, BaseException):
+                    fields["error_type"] = type(error).__name__
+                text = self.redactor.redact_text(str(error))
+                fields["error"] = text[: self.max_error_chars]
+            return self.record_event("llm.call", key=key, attrs=fields)
+        except Exception:
+            logger.warning("Failed to record LLM call", exc_info=True)
+            return False
+
+    async def events_for(
+        self,
+        key: Any,
+        *,
+        kinds: Iterable[str] | None = None,
+        limit: int = 1000,
+    ) -> list[dict[str, Any]]:
+        """Events for ``key``, oldest first: the newest ``limit`` of them.
+
+        Reads the DatabaseSink when there is one and adds events still only in
+        memory, so an event is visible as soon as ``record_event`` returns (on
+        the loop thread). Without a DatabaseSink, memory only. ``occurred_at``
+        is a UTC datetime. A database failure is logged and memory is used.
+        Events are ordered by ``occurred_at``; their ids are random UUIDs.
+        """
+        key = str(key)
+        kinds = None if kinds is None else frozenset(kinds)
+        found: dict[str, dict[str, Any]] = {}
+        sink = self.database_sink
+        if sink is not None:
+            try:
+                for row in await sink.events_for(key, kinds=kinds, limit=limit):
+                    found[row["id"]] = row
+            except Exception:
+                logger.warning("Failed to read events for %r", key, exc_info=True)
+        for record in list(self.recent_events):
+            if record.key == key and (kinds is None or record.kind in kinds):
+                found.setdefault(record.id, record.to_row())
+        rows = list(found.values())
+        for row in rows:
+            row["occurred_at"] = as_utc(row["occurred_at"])
+        rows.sort(key=lambda r: r["occurred_at"])
+        return rows[-limit:] if limit > 0 else []
+
+    @property
+    def embedding_sink(self) -> "EmbeddingSink | None":
+        """The first EmbeddingSink among the sinks, if any."""
+        return _first_sink(self.dispatcher.sinks, "embeddings", "EmbeddingSink")
+
+    async def similar(
+        self,
+        text: str,
+        *,
+        source_types: Iterable[str] | None = None,
+        k: int = 10,
+        min_score: float | None = None,
+    ) -> list[dict[str, Any]]:
+        """Embedded texts most like ``text``, best first. Never raises.
+
+        Needs an EmbeddingSink. Each result has ``source_type``,
+        ``source_id``, ``text``, ``score`` (1 - cosine distance, in [0, 1])
+        and ``created_at``. ``source_types`` limits the search to some of
+        ``feedback``, ``call_error``, ``event`` and ``llm``; ``min_score``
+        drops weaker matches. Returns [] on any failure, logged.
+        """
+        sink = self.embedding_sink
+        if sink is None:
+            logger.warning("similar() needs an EmbeddingSink")
+            return []
+        try:
+            return await sink.similar(
+                str(text),
+                source_types=None if source_types is None else list(source_types),
+                k=k,
+                min_score=min_score,
+            )
+        except Exception:
+            logger.warning("Similarity search failed", exc_info=True)
+            return []
+
+    async def similar_feedback(
+        self,
+        feedback_ref: Any,
+        *,
+        k: int = 10,
+        source_types: Iterable[str] | None = None,
+        min_score: float | None = None,
+    ) -> list[dict[str, Any]]:
+        """Texts most like an embedded feedback item, excluding the item itself.
+
+        Uses the feedback's stored vector, so nothing is embedded. Returns []
+        when the feedback is not embedded yet, and on any failure. Never raises.
+        """
+        sink = self.embedding_sink
+        if sink is None:
+            logger.warning("similar_feedback() needs an EmbeddingSink")
+            return []
+        ref = str(feedback_ref)
+        try:
+            vector = await sink.vector_for("feedback", ref)
+            if vector is None:
+                return []
+            return await sink.nearest(
+                vector,
+                source_types=None if source_types is None else list(source_types),
+                k=k,
+                min_score=min_score,
+                exclude=("feedback", ref),
+            )
+        except Exception:
+            logger.warning("similar_feedback(%r) failed", ref, exc_info=True)
+            return []
+
+    @property
+    def database_sink(self) -> "DatabaseSink | None":
+        """The first DatabaseSink among the sinks, if any."""
+        return _first_sink(self.dispatcher.sinks, "storage", "DatabaseSink")
+
+    async def capture_recent_calls(
+        self,
+        ctx: Any = None,
+        n: int = 20,
+        *,
+        user_sub: str | None = None,
+        window: timedelta = timedelta(minutes=15),
+    ) -> list[CallLink]:
+        """The calls that led up to now, for attaching to a feedback item.
+
+        Call from inside a tool. Returns up to ``n`` calls in chronological
+        order: first from the current MCP session, then, if that yields fewer
+        than ``n``, the same user's calls within ``window``. Each link says
+        which rule matched. Never raises; returns [] on any failure.
+
+        Args:
+            ctx: the FastMCP Context. Looked up automatically when omitted.
+            n: maximum number of calls.
+            user_sub: the caller's user id. When omitted, the identity
+                resolver is asked, given an object whose ``fastmcp_context``
+                is ``ctx``.
+            window: how far back the same-user fallback reaches.
+        """
+        try:
+            if ctx is None:
+                ctx = _current_context()
+            session_id = session_key(ctx)
+            if user_sub is None and self.identity_resolver is not None:
+                identity = await self._call_hook(
+                    self.identity_resolver, ResolverContext(ctx)
+                )
+                user_sub = identity.get("user_sub")
+            since = datetime.now(UTC) - window
+
+            candidates = [
+                Candidate(r.id, r.tool, r.started_at, r.ok, r.session_id, r.user_sub)
+                for r in self.recent
+            ]
+            links = select_calls(
+                candidates,
+                session_id=session_id,
+                user_sub=user_sub,
+                since=since,
+                limit=n,
+            )
+            sink = self.database_sink
+            if sink is not None and len(links) < n:
+                # Other workers, or calls from before a restart.
+                rows = await asyncio.wait_for(
+                    sink.recent_calls(
+                        session_id=session_id, user_sub=user_sub, since=since, limit=n
+                    ),
+                    self.correlation_timeout,
+                )
+                candidates += [
+                    Candidate(
+                        r["id"],
+                        r["tool"],
+                        as_utc(r["started_at"]),
+                        r["ok"],
+                        r["session_id"],
+                        r["user_sub"],
+                    )
+                    for r in rows
+                ]
+                links = select_calls(
+                    candidates,
+                    session_id=session_id,
+                    user_sub=user_sub,
+                    since=since,
+                    limit=n,
+                )
+            return links
+        except Exception:
+            logger.warning("Failed to capture recent calls", exc_info=True)
+            return []
+
+    async def link_feedback(self, feedback_ref: str, links: Sequence[CallLink]) -> bool:
+        """Store ``links`` against a feedback id of any format (``bug-XXXX``, 42).
+
+        Needs a DatabaseSink. Replaces earlier links for the same id. Returns
+        False, without raising, if they could not be stored.
+        """
+        sink = self.database_sink
+        if sink is None:
+            logger.warning("link_feedback needs a DatabaseSink; links not stored")
+            return False
+        linked_at = datetime.now(UTC)
+        try:
+            await sink.replace_links(
+                str(feedback_ref),
+                [
+                    {
+                        "feedback_ref": str(feedback_ref),
+                        "call_id": link.call_id,
+                        "position": link.position,
+                        "rule": link.rule,
+                        "linked_at": linked_at,
+                    }
+                    for link in links
+                ],
+            )
+            return True
+        except Exception:
+            logger.warning("Failed to link feedback %s", feedback_ref, exc_info=True)
+            return False
+
+    async def feedback_context(self, feedback_ref: str) -> list[dict[str, Any]]:
+        """The calls linked to a feedback id, in order, with their details.
+
+        Calls not yet written to the database are filled in from memory.
+        """
+        sink = self.database_sink
+        if sink is None:
+            return []
+        rows = await sink.linked_calls(str(feedback_ref))
+        in_memory = {r.id: r for r in self.recent}
+        for row in rows:
+            if row["tool"] is None and row["call_id"] in in_memory:
+                record = in_memory[row["call_id"]]
+                for key in row:
+                    if key not in ("call_id", "position", "rule"):
+                        row[key] = getattr(record, key, None)
+            if row["started_at"] is not None:
+                row["started_at"] = as_utc(row["started_at"])
+        return rows
+
+    async def flush(self) -> None:
+        """Wait until queued records have reached the sinks."""
+        await self.dispatcher.flush()
+
+    async def aclose(self) -> None:
+        """Flush and close the sinks. Call on server shutdown."""
+        await self.dispatcher.aclose()
+
+
+class _Identity(NamedTuple):
+    """One answer from the identity resolver, redacted.
+
+    ``columns`` holds whichever of user_sub, caller_kind and client_id it
+    returned, ``rest`` everything else, and ``fallback_client_id`` the
+    FastMCP context's client_id for when it returned none.
+    """
+
+    columns: dict[str, Any]
+    rest: dict[str, Any]
+    fallback_client_id: str | None = None
+
+    def column(self, key: str) -> Any:
+        value = self.columns.get(key)
+        if key == "client_id" and not value:
+            return self.fallback_client_id
+        return value
+
+    def filled_from(self, later: "_Identity") -> "_Identity":
+        """This answer, with gaps and None values filled from ``later``.
+
+        Values already here win, so the call's record agrees with the events
+        recorded during the call, which saw only this answer.
+        """
+
+        def fill(first: dict[str, Any], second: dict[str, Any]) -> dict[str, Any]:
+            merged = dict(first)
+            for key, value in second.items():
+                if merged.get(key) is None:
+                    merged[key] = value
+            return merged
+
+        return _Identity(
+            fill(self.columns, later.columns),
+            fill(self.rest, later.rest),
+            self.fallback_client_id or later.fallback_client_id,
+        )
+
+
+def _is_sink(sink: Any, module: str, name: str) -> bool:
+    """isinstance against a sink class without importing its module.
+
+    storage and embeddings need the async database stack. When the module was
+    never imported, no instance of its class can exist, so the answer is no.
+    """
+    loaded = sys.modules.get(f"{__package__}.{module}")
+    cls = getattr(loaded, name, None) if loaded is not None else None
+    return cls is not None and isinstance(sink, cls)
+
+
+def _first_sink(sinks: Iterable[Any], module: str, name: str) -> Any:
+    return next((s for s in sinks if _is_sink(s, module, name)), None)
+
+
+def _current_context() -> Any:
+    try:
+        from fastmcp.server.dependencies import get_context
+
+        return get_context()
+    except Exception:
+        return None
+
+
+def instrument(app: FastMCP, sinks: Sequence[Sink] | None = None, **kwargs: Any):
+    """Add an InstrumentationMiddleware to ``app`` and return it.
+
+    >>> mw = instrument(app)                      # JSON lines to stderr
+    >>> mw = instrument(app, [DatabaseSink(engine)], mode="full")
+    """
+    middleware = InstrumentationMiddleware(sinks, **kwargs)
+    app.add_middleware(middleware)
+    return middleware

src/fastmcp_feedback/instrumentation/payload.py

@@ -0,0 +1,108 @@
+"""Size limits for stored payloads: call arguments and results, event attrs.
+
+A value whose JSON encoding is larger than the limit is stored as a marker:
+
+    {"_truncated": true, "size": 812345, "preview": "{\"frames\": [[0.1, ..."}
+
+``size`` is the value's encoded size in bytes, measured as for ``args_size``
+(``json.dumps(value, default=str)``, non-ASCII escaped). ``preview`` is the
+start of its JSON text, ``preview_chars(limit)`` characters: ``PREVIEW_CHARS``
+(1000) under the default limit, a quarter of the limit under a smaller one,
+so the marker itself fits. It is taken from the value after redaction, so a
+secret cannot reach it. The keys and their meaning are stable.
+"""
+
+import json
+from typing import Any
+
+TRUNCATED = "_truncated"
+PREVIEW_CHARS = 1000
+DEFAULT_MAX_PAYLOAD_BYTES = 64 * 1024
+
+# Incremental, so a preview of a large value encodes only its start.
+_ENCODER = json.JSONEncoder(default=str, ensure_ascii=False)
+
+
+def json_size(value: Any) -> int | None:
+    """Bytes of ``value`` as JSON, or None when it cannot be encoded."""
+    try:
+        return len(json.dumps(value, default=str).encode())
+    except Exception:
+        return None
+
+
+def is_truncated(value: Any) -> bool:
+    """Whether ``value`` is a marker left by the size limit."""
+    return isinstance(value, dict) and value.get(TRUNCATED) is True
+
+
+def preview(value: Any, chars: int = PREVIEW_CHARS) -> str:
+    """The first ``chars`` characters of ``value``'s JSON text."""
+    if chars <= 0:
+        return ""
+    parts: list[str] = []
+    length = 0
+    try:
+        for chunk in _ENCODER.iterencode(value):
+            parts.append(chunk)
+            length += len(chunk)
+            if length >= chars:
+                break
+    except Exception:
+        return ""
+    return "".join(parts)[:chars]
+
+
+def preview_chars(limit: int) -> int:
+    """How much of a value's JSON text a marker keeps under ``limit``."""
+    return min(PREVIEW_CHARS, limit // 4)
+
+
+def marker(value: Any, size: int | None, limit: int) -> dict[str, Any]:
+    """The stand-in stored for a ``value`` over ``limit`` bytes."""
+    return {
+        TRUNCATED: True,
+        "size": size,
+        "preview": preview(value, preview_chars(limit)),
+    }
+
+
+def cap(value: Any, size: int | None, limit: int | None) -> Any:
+    """``value``, or its marker when ``size`` is over ``limit``.
+
+    ``size`` is passed in because the caller has usually measured it already
+    (``args_size``, ``result_size``), so this costs no second encoding.
+    """
+    if limit is None or size is None or size <= limit:
+        return value
+    return marker(value, size, limit)
+
+
+def cap_attrs(attrs: dict[str, Any], limit: int | None) -> dict[str, Any]:
+    """Event attrs within ``limit`` bytes, keeping the dict's keys.
+
+    The largest values are replaced by markers, one at a time, until the
+    whole fits, so small fields (``ok``, ``phase``, ``model``) stay readable.
+    If markers alone cannot get it under the limit (very many keys, or a
+    limit of a few dozen bytes), the whole dict becomes one marker, which
+    under such a tiny limit can itself be larger than the limit.
+    """
+    if limit is None or not attrs:
+        return attrs
+    total = json_size(attrs)
+    if total is None or total <= limit:
+        return attrs
+    sizes = {key: json_size(value) or 0 for key, value in attrs.items()}
+    out = dict(attrs)
+    for key in sorted(sizes, key=sizes.__getitem__, reverse=True):
+        if total <= limit:
+            break
+        stand_in = marker(attrs[key], sizes[key], limit)
+        smaller = sizes[key] - (json_size(stand_in) or 0)
+        if smaller <= 0:
+            continue
+        out[key] = stand_in
+        total -= smaller
+    if total > limit:
+        return marker(attrs, json_size(attrs), limit)
+    return out

src/fastmcp_feedback/instrumentation/record.py

@@ -0,0 +1,62 @@
+"""The per-call record produced by InstrumentationMiddleware."""
+
+import uuid
+from dataclasses import asdict, dataclass, field
+from datetime import datetime
+from typing import Any, ClassVar
+
+
+@dataclass
+class ToolCallRecord:
+    """One MCP tool call, as seen by the instrumentation middleware.
+
+    ``args`` and ``result`` are only populated in ``full`` mode, and are
+    already redacted when they are. Sizes are measured before redaction.
+
+    ``outcome`` is ``ok``, ``error`` (the tool raised) or ``soft_error`` (it
+    returned a result the classifier flagged). ``ok`` is ``outcome == "ok"``;
+    when ``outcome`` is not given it is derived from ``ok``.
+
+    ``sample_rate`` is set on ok calls of a sampled tool: each such row stands
+    for ``1 / sample_rate`` calls. It is None for everything recorded
+    unconditionally, including failures of sampled tools.
+    """
+
+    record_type: ClassVar[str] = "tool_call"
+
+    tool: str
+    started_at: datetime
+    duration_ms: float
+    ok: bool
+    mode: str
+    outcome: str | None = None
+    id: str = field(default_factory=lambda: str(uuid.uuid4()))
+    error_type: str | None = None
+    error_message: str | None = None
+    session_id: str | None = None
+    request_id: str | None = None
+    client_id: str | None = None
+    user_sub: str | None = None
+    caller_kind: str | None = None
+    identity: dict[str, Any] = field(default_factory=dict)
+    server_version: str | None = None
+    args_size: int | None = None
+    result_size: int | None = None
+    args: Any = None
+    result: Any = None
+    extra: dict[str, Any] = field(default_factory=dict)
+    sample_rate: float | None = None
+
+    def __post_init__(self) -> None:
+        if self.outcome is None:
+            self.outcome = "ok" if self.ok else "error"
+
+    def to_row(self) -> dict[str, Any]:
+        """Column values for the tool_calls table."""
+        return asdict(self)
+
+    def to_dict(self) -> dict[str, Any]:
+        """JSON-friendly form, with the timestamp as ISO 8601."""
+        data = asdict(self)
+        data["started_at"] = self.started_at.isoformat()
+        return data

src/fastmcp_feedback/instrumentation/redaction.py

@@ -0,0 +1,125 @@
+"""Secret redaction for recorded tool arguments, results and error text."""
+
+import re
+from collections.abc import Iterable
+from typing import Any
+
+REDACTED = "[REDACTED]"
+TRUNCATED = "[TRUNCATED]"
+
+# Matched after lowercasing and turning "-" into "_", so "Authorization",
+# "X-Api-Key" style variants are covered too.
+DEFAULT_SECRET_KEYS = frozenset(
+    {
+        "token",
+        "access_token",
+        "refresh_token",
+        "id_token",
+        "auth_token",
+        "session_token",
+        "csrf_token",
+        "bearer",
+        "authorization",
+        "proxy_authorization",
+        "cookie",
+        "set_cookie",
+        "password",
+        "passwd",
+        "passphrase",
+        "secret",
+        "client_secret",
+        "api_key",
+        "apikey",
+        "x_api_key",
+        "private_key",
+    }
+)
+
+# github_token, db_password, stripe_api_key, ...
+DEFAULT_SECRET_SUFFIXES = (
+    "_token",
+    "_secret",
+    "_password",
+    "_api_key",
+    "_apikey",
+    "_private_key",
+)
+
+# Values that are secrets wherever they appear, including inside free text.
+DEFAULT_SECRET_PATTERNS = (
+    r"\bbmcp_[A-Za-z0-9_-]{8,}",  # blender-mcp personal access tokens
+    r"\beyJ[A-Za-z0-9_-]{5,}\.[A-Za-z0-9_-]{5,}\.[A-Za-z0-9_-]{5,}",  # JWT
+    r"(?i)\bbearer\s+[A-Za-z0-9._~+/=-]{8,}",
+    r"\bsk-[A-Za-z0-9_-]{16,}",  # OpenAI/Anthropic-style API keys
+    r"\bgh[pousr]_[A-Za-z0-9]{20,}",  # GitHub tokens
+    r"\bgithub_pat_[A-Za-z0-9_]{20,}",
+    r"\bxox[abposr]-[A-Za-z0-9-]{10,}",  # Slack
+    r"\bAKIA[0-9A-Z]{16}\b",  # AWS access key id
+    r"\bpypi-[A-Za-z0-9_-]{16,}",
+)
+
+# "password=hunter2", "api_key: abc" in error messages and logs. The key is
+# kept so the text still says what was removed.
+_KEY_VALUE_TEXT = re.compile(
+    r"(?i)\b(password|passwd|secret|token|api[_-]?key|authorization)(\s*[=:]\s*)[^\s,;&'\"]+"
+)
+
+
+def _normalize_key(key: Any) -> str:
+    return str(key).lower().replace("-", "_")
+
+
+class Redactor:
+    """Replace secrets in nested JSON-like data with a placeholder.
+
+    Dict values are redacted when their key looks like a secret, at any depth.
+    String values anywhere are scanned for secret-shaped substrings. The input
+    is never modified; a redacted copy is returned.
+    """
+
+    def __init__(
+        self,
+        keys: Iterable[str] = DEFAULT_SECRET_KEYS,
+        patterns: Iterable[str] = DEFAULT_SECRET_PATTERNS,
+        *,
+        extra_keys: Iterable[str] = (),
+        extra_patterns: Iterable[str] = (),
+        suffixes: Iterable[str] = DEFAULT_SECRET_SUFFIXES,
+        replacement: str = REDACTED,
+        max_depth: int = 32,
+    ):
+        self.keys = frozenset(_normalize_key(k) for k in (*keys, *extra_keys))
+        self.suffixes = tuple(_normalize_key(s) for s in suffixes)
+        self.patterns = tuple(re.compile(p) for p in (*patterns, *extra_patterns))
+        self.replacement = replacement
+        self.max_depth = max_depth
+
+    def is_secret_key(self, key: Any) -> bool:
+        normalized = _normalize_key(key)
+        return normalized in self.keys or normalized.endswith(self.suffixes)
+
+    def redact_text(self, text: str) -> str:
+        for pattern in self.patterns:
+            text = pattern.sub(self.replacement, text)
+        return _KEY_VALUE_TEXT.sub(
+            lambda m: f"{m.group(1)}{m.group(2)}{self.replacement}", text
+        )
+
+    def redact(self, value: Any) -> Any:
+        return self._redact(value, 0)
+
+    def _redact(self, value: Any, depth: int) -> Any:
+        if depth > self.max_depth:
+            return TRUNCATED
+        if isinstance(value, str):
+            return self.redact_text(value)
+        if isinstance(value, dict):
+            return {
+                k: self.replacement
+                if self.is_secret_key(k) and v is not None
+                else self._redact(v, depth + 1)
+                for k, v in value.items()
+            }
+        if isinstance(value, list | tuple | set | frozenset):
+            return [self._redact(v, depth + 1) for v in value]
+        return value

src/fastmcp_feedback/instrumentation/sinks.py

@@ -0,0 +1,78 @@
+"""Destinations for tool-call and event records."""
+
+import inspect
+import json
+import sys
+from collections.abc import Callable, Sequence
+from typing import IO, Any, Protocol, runtime_checkable
+
+from .events import EventRecord
+from .record import ToolCallRecord
+
+Record = ToolCallRecord | EventRecord
+
+
+@runtime_checkable
+class Sink(Protocol):
+    """Anything with ``async write(records)``. ``async aclose()`` is optional.
+
+    A batch can mix ``ToolCallRecord`` and ``EventRecord``; tell them apart
+    with ``isinstance`` or ``record.record_type`` (``tool_call``, ``event``).
+    """
+
+    async def write(self, records: Sequence[Record]) -> None: ...
+
+
+class JsonLinesSink:
+    """One JSON object per record, to stderr by default.
+
+    Each line has ``"record": "tool_call"`` or ``"record": "event"``.
+    """
+
+    def __init__(self, stream: IO[str] | None = None):
+        self._stream = stream
+
+    async def write(self, records: Sequence[Record]) -> None:
+        # Resolved per write so a stderr swapped by the host or a test is honored.
+        stream = self._stream or sys.stderr
+        for record in records:
+            line = {"record": record.record_type, **record.to_dict()}
+            stream.write(json.dumps(line, default=str) + "\n")
+        stream.flush()
+
+
+class CallbackSink:
+    """Pass each batch to a function, sync or async.
+
+    A sync callback runs on the event loop, so keep it quick.
+    """
+
+    def __init__(self, callback: Callable[[Sequence[Record]], Any]):
+        self.callback = callback
+
+    async def write(self, records: Sequence[Record]) -> None:
+        result = self.callback(records)
+        if inspect.isawaitable(result):
+            await result
+
+
+class MemorySink:
+    """Keep records in a list. Meant for tests.
+
+    ``records`` holds everything in arrival order; ``calls`` and ``events``
+    are the two kinds on their own.
+    """
+
+    def __init__(self):
+        self.records: list[Record] = []
+
+    @property
+    def calls(self) -> list[ToolCallRecord]:
+        return [r for r in self.records if isinstance(r, ToolCallRecord)]
+
+    @property
+    def events(self) -> list[EventRecord]:
+        return [r for r in self.records if isinstance(r, EventRecord)]
+
+    async def write(self, records: Sequence[Record]) -> None:
+        self.records.extend(records)

src/fastmcp_feedback/instrumentation/storage.py

@@ -0,0 +1,546 @@
+"""Async SQLAlchemy storage for tool-call records, events, feedback links and
+embeddings.
+
+Hosts that manage their own schema include ``build_metadata(prefix)`` in their
+Alembic ``env.py`` (``target_metadata``) and pass their existing AsyncEngine to
+``DatabaseSink``. Nothing is created unless ``create_tables=True``.
+"""
+
+import asyncio
+import logging
+import random as _random
+import time
+from collections.abc import Sequence
+from datetime import UTC, datetime, timedelta
+from typing import Any
+
+from sqlalchemy import (
+    JSON,
+    Boolean,
+    Column,
+    DateTime,
+    Float,
+    Index,
+    Integer,
+    MetaData,
+    String,
+    Table,
+    Text,
+    UniqueConstraint,
+    and_,
+    delete,
+    exists,
+    inspect,
+    or_,
+    select,
+    text,
+)
+from sqlalchemy.dialects.postgresql import JSONB
+from sqlalchemy.exc import DBAPIError
+from sqlalchemy.ext.asyncio import AsyncEngine, create_async_engine
+from sqlalchemy.types import TypeDecorator
+
+from .constants import (
+    DEFAULT_EMBEDDING_DIM,
+    DEFAULT_TABLE_PREFIX,
+    FEEDBACK_SOURCE,
+)
+from .constants import EMBEDDING_SOURCES as EMBEDDING_SOURCES  # re-export
+from .events import MAX_KEY_CHARS, MAX_KIND_CHARS, EventRecord
+from .record import ToolCallRecord
+from .sinks import Record
+
+logger = logging.getLogger(__name__)
+
+# none_as_null: a missing payload is SQL NULL, so "WHERE args IS NULL" works.
+_JSON = JSON(none_as_null=True).with_variant(JSONB(none_as_null=True), "postgresql")
+
+
+class EmbeddingVector(TypeDecorator):
+    """pgvector ``VECTOR(dim)`` on PostgreSQL, a JSON list of floats elsewhere.
+
+    pgvector is imported only when a PostgreSQL dialect needs the type, so
+    SQLite hosts never need it installed.
+    """
+
+    impl = JSON
+    cache_ok = True
+
+    def __init__(self, dim: int = DEFAULT_EMBEDDING_DIM):
+        super().__init__()
+        self.dim = dim
+
+    def load_dialect_impl(self, dialect: Any) -> Any:
+        if dialect.name == "postgresql":
+            try:
+                from pgvector.sqlalchemy import VECTOR
+            except ImportError as exc:
+                raise ImportError(
+                    "Embeddings on PostgreSQL need pgvector: install "
+                    '"fastmcp-feedback[embeddings]"'
+                ) from exc
+            return dialect.type_descriptor(VECTOR(self.dim))
+        return dialect.type_descriptor(JSON())
+
+    def process_bind_param(self, value: Any, dialect: Any) -> Any:
+        return None if value is None else [float(v) for v in value]
+
+    def process_result_value(self, value: Any, dialect: Any) -> Any:
+        return None if value is None else [float(v) for v in value]
+
+
+def build_metadata(
+    prefix: str = DEFAULT_TABLE_PREFIX,
+    metadata: MetaData | None = None,
+    embedding_dim: int | None = DEFAULT_EMBEDDING_DIM,
+) -> MetaData:
+    """Return MetaData holding ``{prefix}tool_calls``, ``{prefix}events``,
+    ``{prefix}feedback_call_links`` and ``{prefix}embeddings``.
+
+    Pass an existing MetaData to add the tables to it instead.
+    ``embedding_dim`` sizes the vector column; None leaves the embeddings
+    table out, for hosts that do not embed and have no pgvector.
+    """
+    metadata = metadata if metadata is not None else MetaData()
+    calls = f"{prefix}tool_calls"
+    events = f"{prefix}events"
+    links = f"{prefix}feedback_call_links"
+    embeddings = f"{prefix}embeddings"
+    if calls not in metadata.tables:
+        Table(
+            calls,
+            metadata,
+            Column("id", String(36), primary_key=True),
+            Column("started_at", DateTime(timezone=True), nullable=False, index=True),
+            Column("duration_ms", Float, nullable=False),
+            Column("tool", String(255), nullable=False, index=True),
+            Column("mode", String(8), nullable=False),
+            Column("ok", Boolean, nullable=False, index=True),
+            # ok, soft_error or error. NULL on rows from before 2026.09.27.4.
+            Column("outcome", String(16), index=True),
+            Column("error_type", String(255)),
+            Column("error_message", Text),
+            Column("session_id", String(255), index=True),
+            Column("request_id", String(255)),
+            Column("client_id", String(255)),
+            Column("user_sub", String(255), index=True),
+            Column("caller_kind", String(64)),
+            Column("identity", _JSON),
+            Column("server_version", String(64), index=True),
+            Column("args_size", Integer),
+            Column("result_size", Integer),
+            Column("args", _JSON),
+            Column("result", _JSON),
+            Column("extra", _JSON),
+            # Set on sampled-in ok rows; each stands for 1/sample_rate calls.
+            # NULL for rows recorded unconditionally and before 2026.09.28.
+            Column("sample_rate", Float),
+        )
+    if events not in metadata.tables:
+        # No foreign key to tool_calls for the same reasons as links: an event
+        # can be written before its call leaves the queue, and calls are pruned.
+        Table(
+            events,
+            metadata,
+            Column("id", String(36), primary_key=True),
+            Column("occurred_at", DateTime(timezone=True), nullable=False, index=True),
+            Column("kind", String(MAX_KIND_CHARS), nullable=False, index=True),
+            Column("key", String(MAX_KEY_CHARS), index=True),
+            Column("call_id", String(36), index=True),
+            Column("session_id", String(255)),
+            Column("user_sub", String(255), index=True),
+            Column("caller_kind", String(64)),
+            Column("client_id", String(255)),
+            Column("server_version", String(64)),
+            Column("attrs", _JSON),
+        )
+    if links not in metadata.tables:
+        # No foreign key to tool_calls: a link can be written before its call
+        # record has left the queue, and hosts may keep calls elsewhere.
+        Table(
+            links,
+            metadata,
+            Column("feedback_ref", String(255), primary_key=True),
+            Column("call_id", String(36), primary_key=True, index=True),
+            Column("position", Integer, nullable=False),
+            Column("rule", String(32), nullable=False),
+            Column("linked_at", DateTime(timezone=True), nullable=False),
+        )
+    if embedding_dim is not None and embeddings not in metadata.tables:
+        table = Table(
+            embeddings,
+            metadata,
+            Column("id", String(36), primary_key=True),
+            # feedback, call_error, event or llm
+            Column("source_type", String(16), nullable=False, index=True),
+            # The feedback ref, call id or event id the text came from.
+            Column("source_id", String(255), nullable=False, index=True),
+            Column("model", String(128), nullable=False),
+            Column("dim", Integer, nullable=False),
+            # sha256 hex of ``text``; an unchanged text is not embedded again.
+            Column("text_hash", String(64), nullable=False),
+            # What was embedded: redacted and truncated.
+            Column("text", Text, nullable=False),
+            Column("created_at", DateTime(timezone=True), nullable=False, index=True),
+            Column("embedding", EmbeddingVector(embedding_dim), nullable=False),
+            UniqueConstraint(
+                "source_type", "source_id", "model", name=f"{embeddings}_source_uq"
+            ),
+        )
+        # Cosine HNSW index; other databases search by brute force.
+        Index(
+            f"{embeddings}_hnsw",
+            table.c.embedding,
+            postgresql_using="hnsw",
+            postgresql_ops={"embedding": "vector_cosine_ops"},
+        ).ddl_if(dialect="postgresql")
+    return metadata
+
+
+class DatabaseSink:
+    """Write records to ``{prefix}tool_calls`` and ``{prefix}events``.
+
+    Args:
+        engine: an AsyncEngine the host already owns, or a URL such as
+            ``sqlite+aiosqlite:///calls.db`` or ``postgresql+asyncpg://...``.
+            An engine built from a URL is disposed on ``aclose()``; a passed-in
+            engine is left alone.
+        prefix: table name prefix, so the tables cannot collide with the host's.
+        create_tables: create the tables on first use. Off by default; hosts
+            with Alembic should generate a migration from ``build_metadata``.
+        retention: delete tool-call and event rows older than this. When set, ``write``
+            runs ``prune()`` at most once per ``prune_interval``, after its
+            insert, in the background writer. None (the default) keeps rows
+            forever. Calls linked to feedback are never pruned.
+        prune_interval: minimum time between automatic prunes.
+        prune_batch: rows deleted per statement, so no single delete holds
+            locks for long.
+        embedding_dim: vector size of ``{prefix}embeddings``; must match the
+            embedder of any EmbeddingSink writing through this sink.
+    """
+
+    def __init__(
+        self,
+        engine: AsyncEngine | str,
+        *,
+        prefix: str = DEFAULT_TABLE_PREFIX,
+        create_tables: bool = False,
+        retention: timedelta | None = None,
+        prune_interval: timedelta = timedelta(hours=1),
+        prune_batch: int = 5000,
+        embedding_dim: int = DEFAULT_EMBEDDING_DIM,
+    ):
+        if retention is not None and retention <= timedelta(0):
+            raise ValueError(f"retention must be positive, got {retention!r}")
+        if prune_batch < 1:
+            raise ValueError(f"prune_batch must be at least 1, got {prune_batch!r}")
+        self._owns_engine = isinstance(engine, str)
+        self.engine = create_async_engine(engine) if isinstance(engine, str) else engine
+        self.metadata = build_metadata(prefix, embedding_dim=embedding_dim)
+        self.table = self.metadata.tables[f"{prefix}tool_calls"]
+        self.events = self.metadata.tables[f"{prefix}events"]
+        self.links = self.metadata.tables[f"{prefix}feedback_call_links"]
+        self.embeddings = self.metadata.tables[f"{prefix}embeddings"]
+        self.embedding_dim = embedding_dim
+        self.create_tables = create_tables
+        self._tables_ready = False
+        # The embeddings table (and on Postgres the vector extension) is only
+        # created once an EmbeddingSink uses this sink; see ensure_embeddings.
+        self._embeddings_ready = False
+        self._embeddings_failed_at: float | None = None
+        self._embeddings_lock = asyncio.Lock()
+        # The background writer and link_feedback can both reach _ready() at
+        # once; without the lock both run create_all and one fails.
+        self._tables_lock = asyncio.Lock()
+        self.retention = retention
+        self.prune_interval = prune_interval
+        self.prune_batch = prune_batch
+        # time.monotonic() of the last automatic prune; None until the first.
+        self._last_prune: float | None = None
+
+    async def ensure_tables(self) -> None:
+        """Create the tables if missing. Only called when create_tables=True.
+
+        Another process starting against the same empty database can create a
+        table between our existence check and our CREATE, which fails ours
+        (SQLite: "already exists"; Postgres: DuplicateTable or a unique
+        violation in pg_type). So on a database error, wait a moment and run
+        create_all once more; it skips whatever the other process made. A
+        second failure is raised.
+        """
+        try:
+            await self._create_all()
+        except DBAPIError as first:
+            await asyncio.sleep(_random.uniform(0.05, 0.25))
+            await self._create_all()
+            logger.info(
+                "table creation failed once (%s), retry succeeded; another "
+                "process was probably creating the same tables",
+                type(first).__name__,
+            )
+        self._tables_ready = True
+
+    async def _create_all(self) -> None:
+        # The embeddings table is left to ensure_embeddings, so hosts that do
+        # not embed never need pgvector or the vector extension.
+        tables = [t for t in self.metadata.sorted_tables if t is not self.embeddings]
+        async with self.engine.begin() as conn:
+            await conn.run_sync(self.metadata.create_all, tables=tables)
+
+    async def ensure_embeddings(self) -> bool:
+        """Create ``{prefix}embeddings`` if missing. Only when create_tables=True.
+
+        On PostgreSQL this first runs ``CREATE EXTENSION IF NOT EXISTS vector``.
+        Never raises: a missing privilege, a missing pgvector package or any
+        other failure is logged, and False is returned. A failed attempt is
+        retried at most once a minute. Called by EmbeddingSink before it writes.
+        """
+        if not self.create_tables or self._embeddings_ready:
+            return True
+        async with self._embeddings_lock:
+            if self._embeddings_ready:
+                return True
+            now = time.monotonic()
+            if (
+                self._embeddings_failed_at is not None
+                and now - self._embeddings_failed_at < 60
+            ):
+                return False
+            try:
+                await self._ready()
+                if self.engine.dialect.name == "postgresql":
+                    await self._create_vector_extension()
+                try:
+                    await self._create_embeddings_table()
+                except DBAPIError:
+                    # Another process creating it at the same moment.
+                    await asyncio.sleep(_random.uniform(0.05, 0.25))
+                    await self._create_embeddings_table()
+            except Exception as exc:
+                self._embeddings_failed_at = now
+                logger.warning(
+                    "Could not create %s (%s: %s); embeddings are not stored until "
+                    "it exists. Create it with a migration (see the README) or "
+                    "fix the cause; retrying in a minute.",
+                    self.embeddings.name,
+                    type(exc).__name__,
+                    str(exc).splitlines()[0] if str(exc) else "",
+                )
+                return False
+            self._embeddings_ready = True
+            return True
+
+    async def _create_vector_extension(self) -> None:
+        try:
+            async with self.engine.begin() as conn:
+                await conn.execute(text("CREATE EXTENSION IF NOT EXISTS vector"))
+        except DBAPIError as exc:
+            # Usually a missing privilege. The table step then says whether
+            # the extension exists anyway (a DBA may have created it).
+            logger.warning(
+                "CREATE EXTENSION vector failed (%s); a superuser or database "
+                "owner must run it once in this database",
+                str(exc.orig).splitlines()[0] if exc.orig else type(exc).__name__,
+            )
+
+    async def _create_embeddings_table(self) -> None:
+        async with self.engine.begin() as conn:
+            await conn.run_sync(
+                lambda sync: self.embeddings.create(sync, checkfirst=True)
+            )
+
+    async def _ready(self) -> None:
+        if self.create_tables and not self._tables_ready:
+            async with self._tables_lock:
+                if not self._tables_ready:
+                    await self.ensure_tables()
+
+    async def write(self, records: Sequence[Record]) -> None:
+        calls = [r.to_row() for r in records if isinstance(r, ToolCallRecord)]
+        events = [r.to_row() for r in records if isinstance(r, EventRecord)]
+        if not calls and not events:
+            return
+        await self._ready()
+        # Separate transactions, calls first: a host that has not created the
+        # events table yet still gets its calls stored.
+        if calls:
+            async with self.engine.begin() as conn:
+                await conn.execute(self.table.insert(), calls)
+        if events:
+            async with self.engine.begin() as conn:
+                await conn.execute(self.events.insert(), events)
+        await self._auto_prune()
+
+    async def _auto_prune(self) -> None:
+        if self.retention is None:
+            return
+        now = time.monotonic()
+        if (
+            self._last_prune is not None
+            and now - self._last_prune < self.prune_interval.total_seconds()
+        ):
+            return
+        # Set before running, so a prune that fails is not retried every write.
+        self._last_prune = now
+        try:
+            await self.prune()
+        except Exception:
+            logger.warning("Pruning %s failed", self.table.name, exc_info=True)
+
+    async def prune(self, older_than: datetime | None = None) -> int:
+        """Delete tool-call, event and embedding rows from before ``older_than``.
+
+        Defaults to now minus ``retention``; with neither, deletes nothing.
+        Calls linked to feedback in ``{prefix}feedback_call_links`` are kept,
+        and links are never deleted. Events go by ``occurred_at``, whatever
+        call they belong to. Embeddings go by ``created_at``, except those of
+        feedback (``source_type="feedback"``), which are kept. Deletes
+        ``prune_batch`` rows per transaction until none are left. Returns the
+        total rows deleted from all three tables and logs each table's count.
+        A table that does not exist yet (not migrated) is skipped.
+        """
+        if older_than is None:
+            if self.retention is None:
+                return 0
+            older_than = datetime.now(UTC) - self.retention
+        await self._ready()
+        t, link = self.table, self.links
+        calls = await self._delete_batches(
+            t,
+            select(t.c.id).where(
+                t.c.started_at < older_than,
+                ~exists().where(link.c.call_id == t.c.id),
+            ),
+        )
+        events = 0
+        if await self._has_table(self.events.name):
+            e = self.events
+            events = await self._delete_batches(
+                e, select(e.c.id).where(e.c.occurred_at < older_than)
+            )
+        vectors = 0
+        if await self._has_table(self.embeddings.name):
+            v = self.embeddings
+            vectors = await self._delete_batches(
+                v,
+                select(v.c.id).where(
+                    v.c.created_at < older_than, v.c.source_type != FEEDBACK_SOURCE
+                ),
+            )
+        if calls or events or vectors:
+            logger.info(
+                "Pruned %d rows from %s, %d from %s and %d from %s",
+                calls,
+                t.name,
+                events,
+                self.events.name,
+                vectors,
+                self.embeddings.name,
+            )
+        return calls + events + vectors
+
+    async def _delete_batches(self, table: Any, ids_query: Any) -> int:
+        batch = ids_query.limit(self.prune_batch)
+        total = 0
+        while True:
+            async with self.engine.begin() as conn:
+                ids = (await conn.execute(batch)).scalars().all()
+                if ids:
+                    await conn.execute(delete(table).where(table.c.id.in_(ids)))
+            total += len(ids)
+            if len(ids) < self.prune_batch:
+                return total
+
+    async def _has_table(self, name: str) -> bool:
+        async with self.engine.connect() as conn:
+            return await conn.run_sync(lambda sync: inspect(sync).has_table(name))
+
+    async def events_for(
+        self, key: str, *, kinds: Sequence[str] | None = None, limit: int = 1000
+    ) -> list[dict[str, Any]]:
+        """The newest ``limit`` events for ``key``, newest first."""
+        await self._ready()
+        e = self.events
+        query = select(e).where(e.c.key == key)
+        if kinds is not None:
+            query = query.where(e.c.kind.in_(list(kinds)))
+        query = query.order_by(e.c.occurred_at.desc()).limit(limit)
+        async with self.engine.connect() as conn:
+            return [dict(row) for row in (await conn.execute(query)).mappings()]
+
+    async def recent_calls(
+        self,
+        *,
+        session_id: str | None,
+        user_sub: str | None,
+        since: datetime,
+        limit: int,
+    ) -> list[dict[str, Any]]:
+        """Calls from this session, or from this user since ``since``, newest first."""
+        t = self.table
+        conditions = []
+        if session_id:
+            conditions.append(t.c.session_id == session_id)
+        if user_sub:
+            conditions.append(and_(t.c.user_sub == user_sub, t.c.started_at >= since))
+        if not conditions:
+            return []
+        await self._ready()
+        query = (
+            select(
+                t.c.id, t.c.tool, t.c.started_at, t.c.ok, t.c.session_id, t.c.user_sub
+            )
+            .where(or_(*conditions))
+            .order_by(t.c.started_at.desc())
+            .limit(limit)
+        )
+        async with self.engine.connect() as conn:
+            return [dict(row) for row in (await conn.execute(query)).mappings()]
+
+    async def replace_links(
+        self, feedback_ref: str, links: Sequence[dict[str, Any]]
+    ) -> None:
+        """Set the calls linked to ``feedback_ref``, replacing any earlier set."""
+        await self._ready()
+        async with self.engine.begin() as conn:
+            await conn.execute(
+                delete(self.links).where(self.links.c.feedback_ref == feedback_ref)
+            )
+            if links:
+                await conn.execute(self.links.insert(), list(links))
+
+    async def linked_calls(self, feedback_ref: str) -> list[dict[str, Any]]:
+        """Links for ``feedback_ref`` in order, joined to their call records.
+
+        Call columns are None for calls not (yet) in this database.
+        """
+        await self._ready()
+        link, call = self.links, self.table
+        query = (
+            select(
+                link.c.call_id,
+                link.c.position,
+                link.c.rule,
+                call.c.tool,
+                call.c.started_at,
+                call.c.duration_ms,
+                call.c.ok,
+                call.c.outcome,
+                call.c.error_type,
+                call.c.error_message,
+                call.c.session_id,
+                call.c.user_sub,
+                call.c.caller_kind,
+                call.c.server_version,
+                call.c.extra,
+            )
+            .select_from(link.outerjoin(call, link.c.call_id == call.c.id))
+            .where(link.c.feedback_ref == feedback_ref)
+            .order_by(link.c.position)
+        )
+        async with self.engine.connect() as conn:
+            return [dict(row) for row in (await conn.execute(query)).mappings()]
+
+    async def aclose(self) -> None:
+        if self._owns_engine:
+            await self.engine.dispose()

src/fastmcp_feedback/mixins/base.py

@@ -3,16 +3,31 @@
 import logging
 from datetime import UTC, datetime
 
-from fastmcp.contrib.mcp_mixin import MCPMixin
+from fastmcp.contrib.mcp_mixin import MCPMixin, mcp_tool
 
 from ..database import FeedbackDatabase
 from ..insights import (
     FeedbackInsights,
     record_tool_usage,
 )
+from ..models import Feedback, FeedbackStatus, FeedbackType, feedback_to_dict
 
 logger = logging.getLogger(__name__)
 
+# Explicit re-exports for other mixin modules
+__all__ = [
+    "BaseFeedbackMixin",
+    "Feedback",
+    "FeedbackDatabase",
+    "FeedbackInsights",
+    "FeedbackStatus",
+    "FeedbackType",
+    "feedback_to_dict",
+    "logger",
+    "mcp_tool",
+    "record_tool_usage",
+]
+
 
 class BaseFeedbackMixin(MCPMixin):
     """Base class for all feedback mixins with shared functionality."""

src/fastmcp_feedback/mixins/retrieval.py

@@ -5,6 +5,7 @@ from typing import Any
 
 from sqlalchemy import text
 
+from ..database import count_feedback_by
 from ..insights import record_feedback_retrieval, record_statistics_view
 from .base import BaseFeedbackMixin, Feedback, feedback_to_dict, logger, mcp_tool
 
@@ -93,7 +94,10 @@ class RetrievalMixin(BaseFeedbackMixin):
 
     @mcp_tool(description="Get feedback statistics and analytics")
     async def get_feedback_statistics(self) -> dict[str, Any]:
-        """Get comprehensive feedback statistics.
+        """Feedback counts: total, per type, per status, and the last 7 days.
+
+        ``by_type`` and ``by_status`` are keyed by the same lowercase values
+        ``list_feedback`` returns (``bug``, ``in_progress``).
 
         Returns:
             Dictionary with statistics.
@@ -106,17 +110,10 @@ class RetrievalMixin(BaseFeedbackMixin):
                 total_result = session.execute(text("SELECT COUNT(*) FROM feedback"))
                 total_count = total_result.scalar() or 0
 
-                # Count by type
-                type_result = session.execute(
-                    text("SELECT type, COUNT(*) FROM feedback GROUP BY type")
-                )
-                by_type = dict(type_result.fetchall()) if total_count > 0 else {}
-
-                # Count by status
-                status_result = session.execute(
-                    text("SELECT status, COUNT(*) FROM feedback GROUP BY status")
-                )
-                by_status = dict(status_result.fetchall()) if total_count > 0 else {}
+                # Keyed by enum value ("bug", "open"), as list_feedback
+                # returns them; the database stores the names.
+                by_type = count_feedback_by(session, "type")
+                by_status = count_feedback_by(session, "status")
 
                 # Recent count (last 7 days)
                 week_ago = datetime.now(UTC) - timedelta(days=7)

src/fastmcp_feedback/mixins/submission.py

@@ -1,15 +1,37 @@
 """Submission mixin for feedback collection."""
 
 from datetime import UTC, datetime
-from typing import Any
+from typing import TYPE_CHECKING, Any
 
 from ..insights import record_feedback_submission
 from ..models import SubmitFeedbackRequest, create_feedback_from_request
-from .base import BaseFeedbackMixin, logger, mcp_tool
+from .base import (
+    BaseFeedbackMixin,
+    FeedbackDatabase,
+    FeedbackInsights,
+    logger,
+    mcp_tool,
+)
+
+if TYPE_CHECKING:
+    from ..instrumentation import InstrumentationMiddleware
 
 
 class SubmissionMixin(BaseFeedbackMixin):
-    """Mixin for feedback submission functionality."""
+    """Mixin for feedback submission functionality.
+
+    Pass an InstrumentationMiddleware to link each submission to the tool
+    calls that led up to it and record a ``feedback.submitted`` event for it.
+    """
+
+    def __init__(
+        self,
+        database: FeedbackDatabase,
+        insights: FeedbackInsights | None = None,
+        instrumentation: "InstrumentationMiddleware | None" = None,
+    ):
+        super().__init__(database, insights)
+        self.instrumentation = instrumentation
 
     @mcp_tool(
         description="Submit feedback about your MCP experience - Use this tool when you encounter issues, have suggestions for improvement, or want to report positive experiences. AI models should proactively use this to help improve future MCP sessions. PRIVACY: Only include information you've already shared via previous MCP calls. Ask human permission before including any new sensitive data."
@@ -62,14 +84,34 @@ class SubmissionMixin(BaseFeedbackMixin):
                     source="mcp_tool",
                 )
 
+            linked_calls = 0
+            if self.instrumentation is not None:
+                # Feeds an EmbeddingSink, so similar reports can be found.
+                self.instrumentation.record_event(
+                    "feedback.submitted",
+                    key=feedback_id,
+                    attrs={
+                        "type": request.type,
+                        "title": request.title,
+                        "description": request.description,
+                        "submitter": request.submitter,
+                    },
+                )
+                links = await self.instrumentation.capture_recent_calls()
+                if await self.instrumentation.link_feedback(feedback_id, links):
+                    linked_calls = len(links)
+
             self._record_tool_usage("submit_feedback", start_time, True)
             logger.info(f"Feedback submitted successfully: {feedback_id}")
 
-            return {
+            response = {
                 "success": True,
                 "feedback_id": feedback_id,
                 "message": "Feedback submitted successfully",
             }
+            if self.instrumentation is not None:
+                response["linked_calls"] = linked_calls
+            return response
 
         except Exception as e:
             logger.error(f"Failed to submit feedback: {e}")

src/fastmcp_feedback/tools.py

@@ -17,6 +17,7 @@ def add_feedback_tools(
     insights: FeedbackInsights | None = None,
     prefix: str = "",
     separator: str = "_",
+    instrumentation=None,
 ) -> None:
     """Add all feedback tools to a FastMCP server.
 
@@ -29,6 +30,9 @@ def add_feedback_tools(
         insights: Optional insights instance. Creates default if not provided.
         prefix: Optional prefix for tool names.
         separator: Separator between prefix and tool name.
+        instrumentation: an InstrumentationMiddleware (see ``instrument``).
+            When given, each submission is linked to the tool calls that led
+            up to it, and the response reports ``linked_calls``.
     """
     try:
         # Initialize database
@@ -39,7 +43,7 @@ def add_feedback_tools(
             insights = FeedbackInsights()
 
         # Create mixin instances
-        submission_mixin = SubmissionMixin(database, insights)
+        submission_mixin = SubmissionMixin(database, insights, instrumentation)
         retrieval_mixin = RetrievalMixin(database, insights)
         management_mixin = ManagementMixin(database, insights)
 

tests/_compat.py

@@ -0,0 +1,10 @@
+"""Helpers that paper over FastMCP API differences between 2.x and 4.x."""
+
+from fastmcp import FastMCP
+
+
+async def tool_map(server: FastMCP) -> dict:
+    """Return {name: Tool}. 2.x has get_tools() -> dict, 4.x has list_tools() -> list."""
+    if hasattr(server, "get_tools"):
+        return await server.get_tools()
+    return {tool.name: tool for tool in await server.list_tools()}

tests/_databases.py

@@ -0,0 +1,114 @@
+"""Fresh databases for DatabaseSink tests: SQLite always, Postgres when asked.
+
+Set FFB_TEST_DATABASE_URL to a ``postgresql+asyncpg://`` URL (``make test-pg``
+does this from .env) and every test using the ``db_url`` fixture also runs
+against that server. Each test gets its own uniquely named databases, created
+on first use and dropped at teardown, so no two tests share tables.
+"""
+
+import asyncio
+import os
+import re
+import threading
+import uuid
+from collections.abc import Coroutine
+from typing import Any
+
+from sqlalchemy import text
+from sqlalchemy.engine import URL, make_url
+from sqlalchemy.ext.asyncio import create_async_engine
+from sqlalchemy.pool import NullPool
+
+ENV_VAR = "FFB_TEST_DATABASE_URL"
+SKIP_REASON = f"{ENV_VAR} is not set; run `make pg-up` then `make test-pg`"
+
+
+def postgres_url() -> URL | None:
+    raw = os.environ.get(ENV_VAR, "").strip()
+    if not raw:
+        return None
+    url = make_url(raw)
+    if not url.drivername.startswith("postgresql"):
+        raise ValueError(f"{ENV_VAR} must be a postgresql URL, got {url.drivername}")
+    return url
+
+
+def run_blocking(coro: Coroutine[Any, Any, Any]) -> Any:
+    """Run ``coro`` to completion on its own loop in a worker thread.
+
+    The sink factories in the tests are plain functions called from inside a
+    running event loop, so the admin work cannot await on that loop.
+    """
+    box: dict[str, Any] = {}
+
+    def target() -> None:
+        try:
+            box["value"] = asyncio.run(coro)
+        except BaseException as exc:  # re-raised in the caller's thread
+            box["error"] = exc
+
+    thread = threading.Thread(target=target)
+    thread.start()
+    thread.join()
+    if "error" in box:
+        raise box["error"]
+    return box.get("value")
+
+
+class PostgresDatabases:
+    """Create databases on one server for a single test, then drop them all."""
+
+    def __init__(self, url: URL):
+        self.url = url
+        self.run_id = uuid.uuid4().hex[:10]
+        self.by_label: dict[str, str] = {}
+
+    def _admin(self, database: str | None = None):
+        url = self.url if database is None else self.url.set(database=database)
+        return create_async_engine(
+            url, isolation_level="AUTOCOMMIT", poolclass=NullPool
+        )
+
+    def url_for(self, label: str) -> str:
+        """URL of this test's database for ``label``, created on first request."""
+        if label not in self.by_label:
+            safe = re.sub(r"[^a-z0-9_]", "_", label.lower())
+            name = f"ffb_t_{self.run_id}_{safe}"[:63]
+            run_blocking(self._create(name))
+            self.by_label[label] = name
+        return self.url.set(database=self.by_label[label]).render_as_string(
+            hide_password=False
+        )
+
+    async def _create(self, name: str) -> None:
+        engine = self._admin()
+        try:
+            async with engine.connect() as conn:
+                await conn.execute(text(f'CREATE DATABASE "{name}"'))
+        finally:
+            await engine.dispose()
+        # The compose init script puts vector in template1 already; CI's
+        # service container has no init script, so make sure here.
+        engine = self._admin(name)
+        try:
+            async with engine.connect() as conn:
+                await conn.execute(text("CREATE EXTENSION IF NOT EXISTS vector"))
+        finally:
+            await engine.dispose()
+
+    def drop_all(self) -> None:
+        if self.by_label:
+            run_blocking(self._drop(list(self.by_label.values())))
+            self.by_label.clear()
+
+    async def _drop(self, names: list[str]) -> None:
+        engine = self._admin()
+        try:
+            async with engine.connect() as conn:
+                for name in names:
+                    # FORCE: a sink a test forgot to close must not keep it alive.
+                    await conn.execute(
+                        text(f'DROP DATABASE IF EXISTS "{name}" WITH (FORCE)')
+                    )
+        finally:
+            await engine.dispose()

tests/conftest.py

@@ -16,6 +16,8 @@ from fastmcp_feedback.database import FeedbackDatabase
 from fastmcp_feedback.insights import FeedbackInsights  
 from fastmcp_feedback.models import Base, Feedback, FeedbackType, FeedbackStatus
 
+from ._databases import SKIP_REASON, PostgresDatabases, postgres_url
+
 
 @pytest_asyncio.fixture
 async def event_loop():
@@ -177,6 +179,37 @@ def mock_database(mock_session):
     return db
 
 
+# Database backends for DatabaseSink tests
+
+@pytest.fixture(
+    params=["sqlite", pytest.param("postgres", marks=pytest.mark.postgres)]
+)
+def db_backend(request) -> str:
+    """Which database a ``db_url`` test runs on. Postgres needs FFB_TEST_DATABASE_URL."""
+    if request.param == "postgres" and postgres_url() is None:
+        pytest.skip(SKIP_REASON)
+    return request.param
+
+
+@pytest.fixture
+def db_url(db_backend, tmp_path):
+    """Factory: ``db_url(name)`` returns an async URL for an empty database.
+
+    The same name within one test returns the same database, so a test can
+    reopen it; different names and different tests never share one. SQLite
+    databases are files under tmp_path; Postgres ones are created on the
+    server named by FFB_TEST_DATABASE_URL and dropped after the test.
+    """
+    if db_backend == "sqlite":
+        yield lambda name="calls": f"sqlite+aiosqlite:///{tmp_path}/{name}.db"
+        return
+    databases = PostgresDatabases(postgres_url())
+    try:
+        yield lambda name="calls": databases.url_for(name)
+    finally:
+        databases.drop_all()
+
+
 # Environment helpers
 
 @pytest.fixture(autouse=True)

tests/fixtures/base_install_worker.py

@@ -0,0 +1,105 @@
+"""Exercise the instrumentation as a base install would, then print JSON.
+
+Run in a fresh interpreter. greenlet and aiosqlite are made unimportable
+before anything else loads, as on ``pip install fastmcp-feedback`` without
+the ``instrumentation`` extra. Argument: a directory for the feedback database.
+"""
+
+import sys
+from importlib.metadata import version
+
+# SQLAlchemy 2.1 refuses to import sqlalchemy.ext.asyncio without greenlet,
+# once: a second import succeeds. 2.0 imports it and fails on first use.
+# On 2.0 the module is blocked too, so both versions fail at import.
+_blocked = ["greenlet", "aiosqlite"]
+if tuple(int(p) for p in version("sqlalchemy").split(".")[:2]) < (2, 1):
+    _blocked.append("sqlalchemy.ext.asyncio")
+for _name in _blocked:
+    sys.modules[_name] = None  # import raises ModuleNotFoundError
+
+import asyncio  # noqa: E402
+import io  # noqa: E402
+import json  # noqa: E402
+from pathlib import Path  # noqa: E402
+
+STORAGE = "fastmcp_feedback.instrumentation.storage"
+EMBEDDINGS = "fastmcp_feedback.instrumentation.embeddings"
+
+
+async def run(db_dir: Path) -> dict:
+    from fastmcp import Client, FastMCP
+
+    import fastmcp_feedback.instrumentation as inst
+    from fastmcp_feedback import add_feedback_tools
+    from fastmcp_feedback.instrumentation import (
+        DEFAULT_TABLE_PREFIX,
+        JsonLinesSink,
+        MemorySink,
+        instrument,
+    )
+
+    out: dict = {"prefix": DEFAULT_TABLE_PREFIX}
+    app = FastMCP("base-install")
+
+    @app.tool
+    def add(a: int, b: int) -> int:
+        return a + b
+
+    memory = MemorySink()
+    lines = io.StringIO()
+    mw = instrument(app, [memory, JsonLinesSink(lines)], mode="full")
+    add_feedback_tools(
+        app, database_url=f"sqlite:///{db_dir / 'fb.db'}", instrumentation=mw
+    )
+
+    async with Client(app) as client:
+        result = await client.call_tool("add", {"a": 2, "b": 3})
+        out["result"] = result.content[0].text
+        fb = await client.call_tool(
+            "submit_feedback",
+            {
+                "request": {
+                    "type": "bug",
+                    "title": "base install",
+                    "description": "submitted without the extra",
+                    "submitter": "worker",
+                }
+            },
+        )
+        out["feedback"] = json.loads(fb.content[0].text)
+
+    mw.record_event("job.done", key="j1", attrs={"n": 1})
+    await mw.flush()
+    out["tools"] = [r.tool for r in memory.records if hasattr(r, "tool")]
+    out["event_kinds"] = [r.kind for r in memory.records if hasattr(r, "kind")]
+    out["jsonl_lines"] = len(lines.getvalue().splitlines())
+    out["capture"] = await mw.capture_recent_calls()
+    out["similar"] = await mw.similar("anything")
+    out["similar_feedback"] = await mw.similar_feedback("bug-1")
+    out["feedback_context"] = await mw.feedback_context("bug-1")
+    out["link_feedback"] = await mw.link_feedback("bug-1", [])
+    out["events_for"] = len(await mw.events_for("j1"))
+    out["database_sink"] = mw.database_sink is None
+    out["embedding_sink"] = mw.embedding_sink is None
+    await mw.aclose()
+
+    errors = {}
+    for name in (
+        "DatabaseSink",
+        "EmbeddingSink",
+        "build_metadata",
+        "backfill_feedback",
+    ):
+        for _attempt in range(2):  # SQLAlchemy only complains the first time
+            try:
+                getattr(inst, name)
+                errors.setdefault(name, []).append(None)
+            except ImportError as exc:
+                errors.setdefault(name, []).append(str(exc))
+    out["errors"] = errors
+    out["loaded"] = sorted(m for m in (STORAGE, EMBEDDINGS) if m in sys.modules)
+    return out
+
+
+if __name__ == "__main__":
+    print(json.dumps(asyncio.run(run(Path(sys.argv[1]))), default=str))

tests/fixtures/create_tables_race_worker.py

@@ -0,0 +1,39 @@
+"""One writer process for the cross-process create_tables race test.
+
+Usage: python create_tables_race_worker.py <db url> <trigger file> <events>
+
+Builds a DatabaseSink with create_tables=True, waits until the trigger file
+exists so every worker hits the empty database at the same moment, records
+events, flushes, and prints {"sink_errors": n} as JSON. Prints "ready" once
+imports and setup are done, so the parent can release all workers together.
+"""
+
+import asyncio
+import json
+import os
+import sys
+import time
+
+from fastmcp_feedback.instrumentation import DatabaseSink, InstrumentationMiddleware
+
+
+async def main(url: str, trigger: str, count: int) -> dict:
+    sink = DatabaseSink(url, create_tables=True)
+    mw = InstrumentationMiddleware([sink])
+    print("ready", flush=True)
+    deadline = time.monotonic() + 30
+    while not os.path.exists(trigger):
+        if time.monotonic() > deadline:
+            raise SystemExit("trigger file never appeared")
+        await asyncio.sleep(0.001)
+    for i in range(count):
+        mw.record_event("race.write", key=f"{os.getpid()}-{i}")
+    await mw.flush()
+    errors = mw.dispatcher.sink_errors
+    await mw.aclose()  # also disposes the sink's engine
+    return {"sink_errors": errors}
+
+
+if __name__ == "__main__":
+    url, trigger, count = sys.argv[1], sys.argv[2], int(sys.argv[3])
+    print(json.dumps(asyncio.run(main(url, trigger, count))), flush=True)

tests/fixtures/stdio_correlation_server.py

@@ -0,0 +1,22 @@
+"""A stdio MCP server used by test_correlation to check session linking end to end."""
+
+from fastmcp import Context, FastMCP
+
+from fastmcp_feedback.instrumentation import MemorySink, instrument
+
+app = FastMCP("stdio-correlation")
+mw = instrument(app, [MemorySink()])
+
+
+@app.tool
+def echo(text: str) -> str:
+    return text
+
+
+@app.tool
+async def report(ctx: Context) -> list:
+    return [[link.tool, link.rule] for link in await mw.capture_recent_calls(ctx)]
+
+
+if __name__ == "__main__":
+    app.run(show_banner=False)

tests/integration/test_demo_servers.py

@@ -11,11 +11,14 @@ import sys
 from pathlib import Path
 from unittest.mock import patch
 
+from sqlalchemy import text
+
 # Add the examples directory to the path for imports
 sys.path.insert(0, str(Path(__file__).parent.parent.parent / "examples"))
 
 from fastmcp import FastMCP
 from fastmcp_feedback import FeedbackDatabase, FeedbackInsights
+from tests._compat import tool_map
 
 
 @pytest.mark.asyncio
@@ -35,7 +38,7 @@ class TestDemoServerIntegration:
         assert "demonstration" in server.description.lower()
         
         # Get all tools
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         
         # Verify all expected tools are present
         expected_tools = {
@@ -72,12 +75,12 @@ class TestDemoServerIntegration:
             from fastmcp_feedback.models import Feedback
             async with database.session() as session:
                 # Count feedback items
-                result = session.execute("SELECT COUNT(*) FROM feedback")
+                result = session.execute(text("SELECT COUNT(*) FROM feedback"))
                 count = result.scalar()
                 assert count >= 5, f"Expected at least 5 sample items, got {count}"
                 
                 # Verify types are present
-                result = session.execute("SELECT DISTINCT type FROM feedback")
+                result = session.execute(text("SELECT DISTINCT type FROM feedback"))
                 types = [row[0] for row in result.fetchall()]
                 expected_types = {"BUG", "FEATURE", "IMPROVEMENT", "QUESTION"}
                 assert expected_types.issubset(set(types)), f"Missing feedback types: {expected_types - set(types)}"
@@ -89,21 +92,19 @@ class TestDemoServerIntegration:
         """Test actual execution of demo server tools."""
         from demo_server import create_demo_server, create_temp_database, setup_demo_data
         
-        # Create server with temporary database
-        server = create_demo_server()
-        
-        # Override database URL for testing
+        # Seed a temporary database, then point the server at it
         db_url = create_temp_database()
         database = FeedbackDatabase(db_url)
         await setup_demo_data(database)
+        server = create_demo_server(database_url=db_url)
         
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         
         # Test system info tool
         system_info_tool = tools["get_system_info"]
         info_result = await system_info_tool.run({})
-        assert info_result.structured_content["success"] is True
-        assert "version" in info_result.structured_content
+        assert info_result.structured_content["status"] == "running"
+        assert "versions" in info_result.structured_content
         assert "dependencies" in info_result.structured_content
         
         # Test statistics tool (should work with sample data)
@@ -126,7 +127,7 @@ class TestDemoServerIntegration:
         add_feedback_tools(app, database_url="sqlite:///:memory:")
         
         # Verify tools were added
-        tools = await app.get_tools()
+        tools = await tool_map(app)
         expected_tools = {
             "submit_feedback",
             "list_feedback",
@@ -176,7 +177,7 @@ class TestDemoServerIntegration:
         from demo_server import create_demo_server
         
         server = create_demo_server()
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         
         # Test submit_feedback with invalid data
         submit_tool = tools["submit_feedback"]
@@ -199,7 +200,7 @@ class TestDemoServerIntegration:
         from demo_server import create_demo_server, create_temp_database
         
         server = create_demo_server()
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         
         # Submit feedback
         submit_tool = tools["submit_feedback"]
@@ -225,7 +226,7 @@ class TestDemoServerIntegration:
         assert our_feedback is not None, "Submitted feedback not found in list"
         assert our_feedback["title"] == test_feedback["title"]
         assert our_feedback["type"] == test_feedback["type"]
-        assert our_feedback["status"] == "OPEN"
+        assert our_feedback["status"] == "open"
         
         # Update feedback status
         update_tool = tools["update_feedback_status"]
@@ -239,7 +240,7 @@ class TestDemoServerIntegration:
         list_result = await list_tool.run({})
         feedback_list = list_result.structured_content["feedback"]
         updated_feedback = next((f for f in feedback_list if f["id"] == feedback_id), None)
-        assert updated_feedback["status"] == "IN_PROGRESS"
+        assert updated_feedback["status"] == "in_progress"
         
         # Get statistics (should include our feedback)
         stats_tool = tools["get_feedback_statistics"]
@@ -247,9 +248,10 @@ class TestDemoServerIntegration:
         stats = stats_result.structured_content
         
         assert stats["total_count"] >= 1
-        assert "FEATURE" in stats["by_type"]
-        assert stats["by_type"]["FEATURE"] >= 1
-        assert "IN_PROGRESS" in stats["by_status"]
+        # Keyed by the values list_feedback returns, not the stored names.
+        assert "feature" in stats["by_type"]
+        assert stats["by_type"]["feature"] >= 1
+        assert "in_progress" in stats["by_status"]
         
         # Delete feedback
         delete_tool = tools["delete_feedback"]
@@ -272,7 +274,7 @@ class TestDemoServerDocumentation:
         from demo_server import create_demo_server
         
         server = create_demo_server()
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         
         # According to demo_server.md, should have exactly 7 tools
         assert len(tools) == 7, f"Expected 7 tools as documented, got {len(tools)}"
@@ -296,7 +298,7 @@ class TestDemoServerDocumentation:
         app = FastMCP("Test App")
         add_feedback_tools(app, database_url="sqlite:///:memory:")
         
-        tools = await app.get_tools()
+        tools = await tool_map(app)
         assert len(tools) == 5, f"Expected 5 tools as documented, got {len(tools)}"
         
         # Verify documented tool names
@@ -318,7 +320,7 @@ class TestDemoServerPerformance:
         from demo_server import create_demo_server
         
         server = create_demo_server()
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         submit_tool = tools["submit_feedback"]
         
         # Submit multiple feedback items concurrently

tests/integration/test_full_workflow.py

@@ -10,6 +10,7 @@ from fastmcp_feedback.feedback import create_feedback_server
 from fastmcp_feedback.models import SubmitFeedbackRequest, FeedbackStatus
 from fastmcp_feedback.database import FeedbackDatabase
 from fastmcp_feedback.insights import FeedbackInsights
+from tests._compat import tool_map
 
 
 @pytest.mark.integration
@@ -25,7 +26,7 @@ class TestCompleteWorkflow:
         add_feedback_tools(server, database_url=memory_db_url, insights=insights)
         
         # Get tools
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         submit_tool = tools["submit_feedback"]
         list_tool = tools["list_feedback"]
         update_tool = tools["update_feedback_status"]
@@ -60,10 +61,10 @@ class TestCompleteWorkflow:
         stats = stats_result.structured_content
         
         assert stats["total_count"] >= 1
-        assert "BUG" in stats["by_type"]
-        assert stats["by_type"]["BUG"] >= 1
-        assert "OPEN" in stats["by_status"]
-        assert stats["by_status"]["OPEN"] >= 1
+        assert "bug" in stats["by_type"]
+        assert stats["by_type"]["bug"] >= 1
+        assert "open" in stats["by_status"]
+        assert stats["by_status"]["open"] >= 1
         
         # 4. Update feedback status
         update_result = await update_tool.run({
@@ -93,8 +94,8 @@ class TestCompleteWorkflow:
         final_stats_result = await stats_tool.run({})
         final_stats = final_stats_result.structured_content
         
-        assert "RESOLVED" in final_stats["by_status"]
-        assert final_stats["by_status"]["RESOLVED"] >= 1
+        assert "resolved" in final_stats["by_status"]
+        assert final_stats["by_status"]["resolved"] >= 1
         
         # 8. Verify insights were recorded
         assert len(insights.get_metrics("feedback_submitted")) >= 1
@@ -106,7 +107,7 @@ class TestCompleteWorkflow:
         server = FastMCP("Multi-Type Test Server")
         add_feedback_tools(server, database_url=memory_db_url)
         
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         submit_tool = tools["submit_feedback"]
         list_tool = tools["list_feedback"]
         
@@ -179,7 +180,7 @@ class TestCompleteWorkflow:
         server = FastMCP("Error Test Server")
         add_feedback_tools(server, database_url=memory_db_url)
         
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         submit_tool = tools["submit_feedback"]
         update_tool = tools["update_feedback_status"]
         delete_tool = tools["delete_feedback"]
@@ -233,7 +234,7 @@ class TestCompleteWorkflow:
         insights = FeedbackInsights(enabled=True)
         add_feedback_tools(server, database_url=memory_db_url, insights=insights)
         
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         submit_tool = tools["submit_feedback"]
         list_tool = tools["list_feedback"]
         
@@ -285,7 +286,7 @@ class TestCompleteWorkflow:
         server = FastMCP("Bulk Test Server")
         add_feedback_tools(server, database_url=memory_db_url)
         
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         submit_tool = tools["submit_feedback"]
         list_tool = tools["list_feedback"]
         update_tool = tools["update_feedback_status"]
@@ -355,7 +356,7 @@ class TestServerCompositionWorkflow:
         )
         
         # Get tools from dedicated server
-        tools = await feedback_server.get_tools()
+        tools = await tool_map(feedback_server)
         submit_tool = tools["submit_feedback"]
         list_tool = tools["list_feedback"]
         
@@ -384,11 +385,11 @@ class TestServerCompositionWorkflow:
         admin_feedback = create_feedback_server("Admin Feedback", database_url="sqlite:///:memory:")
         
         # Import servers with different prefixes
-        await main_server.import_server(user_feedback, prefix="user")
-        await main_server.import_server(admin_feedback, prefix="admin")
+        main_server.mount(user_feedback, "user")
+        main_server.mount(admin_feedback, "admin")
         
         # Get tools
-        tools = await main_server.get_tools()
+        tools = await tool_map(main_server)
         
         user_submit = tools["user_submit_feedback"]
         admin_submit = tools["admin_submit_feedback"]
@@ -439,7 +440,7 @@ class TestServerCompositionWorkflow:
         add_feedback_tools(server, database_url=memory_db_url, prefix="public")
         add_feedback_tools(server, database_url=memory_db_url, prefix="internal")
         
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         
         public_submit = tools["public_submit_feedback"]
         internal_submit = tools["internal_submit_feedback"]
@@ -490,7 +491,7 @@ class TestPerformanceWorkflow:
         insights = FeedbackInsights(enabled=True)
         add_feedback_tools(server, database_url=memory_db_url, insights=insights)
         
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         submit_tool = tools["submit_feedback"]
         list_tool = tools["list_feedback"]
         stats_tool = tools["get_feedback_statistics"]
@@ -525,8 +526,8 @@ class TestPerformanceWorkflow:
         stats_result = await stats_tool.run({})
         stats = stats_result.structured_content
         assert stats["total_count"] >= 100
-        assert "IMPROVEMENT" in stats["by_type"]
-        assert stats["by_type"]["IMPROVEMENT"] >= 100
+        assert "improvement" in stats["by_type"]
+        assert stats["by_type"]["improvement"] >= 100
         
         # Insights should have recorded all submissions
         submit_metrics = insights.get_metrics("feedback_submitted")
@@ -537,7 +538,7 @@ class TestPerformanceWorkflow:
         server = FastMCP("Filter Performance Server")
         add_feedback_tools(server, database_url=memory_db_url)
         
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         submit_tool = tools["submit_feedback"]
         list_tool = tools["list_feedback"]
         update_tool = tools["update_feedback_status"]
@@ -611,7 +612,7 @@ class TestPerformanceWorkflow:
         server = FastMCP("Concurrent Mixed Server")
         add_feedback_tools(server, database_url=memory_db_url)
         
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         submit_tool = tools["submit_feedback"]
         list_tool = tools["list_feedback"]
         update_tool = tools["update_feedback_status"]

tests/unit/test_backfill.py

@@ -0,0 +1,565 @@
+"""Tests for backfill_embeddings, backfill_feedback, its CLI, and list/dict
+text flattening.
+
+DB tests take the ``db_url`` fixture, so they run on SQLite and, with
+FFB_TEST_DATABASE_URL set, on Postgres with pgvector.
+"""
+
+import json
+import os
+import subprocess
+import sys
+from datetime import UTC, datetime, timedelta
+
+import pytest
+from sqlalchemy import func, select, update
+
+from fastmcp_feedback.instrumentation import (
+    REDACTED,
+    DatabaseSink,
+    EmbeddingSink,
+    EventRecord,
+    Redactor,
+    backfill_embeddings,
+    backfill_feedback,
+    extract_texts,
+)
+from fastmcp_feedback.instrumentation.backfill.cli import main as cli_main
+
+from .test_embeddings import DIM, SECRET, FakeEmbedder, call_record, event, rows
+
+T0 = datetime(2026, 9, 1, 12, 0, tzinfo=UTC)
+
+
+@pytest.fixture
+async def db(db_url):
+    made = []
+
+    def factory(name="calls", **kwargs):
+        kwargs.setdefault("create_tables", True)
+        kwargs.setdefault("embedding_dim", DIM)
+        sink = DatabaseSink(db_url(name), **kwargs)
+        made.append(sink)
+        return sink
+
+    yield factory
+    for sink in made:
+        await sink.engine.dispose()
+
+
+def at(minutes: float) -> datetime:
+    return T0 + timedelta(minutes=minutes)
+
+
+def error_call(minute, tool="render", message="render timed out", **kw):
+    record = call_record(tool=tool, message=message, **kw)
+    record.started_at = at(minute)
+    return record
+
+
+def ev(minute, kind, key=None, **attrs):
+    record = event(kind, key, **attrs)
+    record.occurred_at = at(minute)
+    return record
+
+
+def mixed_records():
+    """One of everything backfill should pick up, and some it should not."""
+    return [
+        error_call(1, message="render timed out after 30s"),
+        error_call(2, tool="find", outcome="soft_error", message="no object Cube"),
+        call_record(outcome="ok"),
+        ev(
+            3, "feedback.submitted", "bug-1", title="Render hangs", description="at 99%"
+        ),
+        ev(
+            4, "llm.call", model="m", prompt="summarize the log", completion="it failed"
+        ),
+        ev(5, "llm.call", model="m", ok=False, error="rate limited"),
+        ev(6, "llm.call", model="m", ok=True),
+        ev(7, "job.failed", "job-1", error_excerpt=["line one", "line two"]),
+        ev(8, "job.progress", "job-1", percent=50),
+    ]
+
+
+def keyed(stored):
+    return {(r["source_type"], r["source_id"]): r for r in stored}
+
+
+async def count_rows(sink):
+    t = sink.embeddings
+    async with sink.engine.connect() as conn:
+        return (await conn.execute(select(func.count()).select_from(t))).scalar_one()
+
+
+class TestFlattening:
+    def test_list_and_tuple_join_lines(self):
+        records = [
+            event("job.failed", error_excerpt=["  a  ", "", None, "b"]),
+            event("job.failed", error=("x", 1, 2.5)),
+        ]
+        texts = [t.text for t in extract_texts(records)]
+        assert texts == ["a\nb", "x\n1\n2.5"]
+
+    def test_dict_becomes_sorted_key_lines(self):
+        records = [event("job.failed", error={"zeta": "last", "alpha": 1, "mid": None})]
+        [item] = extract_texts(records)
+        assert item.text == "alpha: 1\nzeta: last"
+
+    def test_nested(self):
+        records = [
+            event(
+                "job.failed",
+                error_excerpt=[["a", "b"], {"k": ["c", "d"]}, ("e",)],
+            )
+        ]
+        [item] = extract_texts(records)
+        assert item.text == "a\nb\nk: c\nd\ne"
+        assert "[" not in item.text and "{" not in item.text
+
+    def test_flattening_applies_to_feedback_and_llm(self):
+        records = [
+            event("feedback.submitted", "f1", title=["Two", "parts"], description=None),
+            event("llm.call", prompt=["p1", "p2"], completion={"text": "done"}),
+        ]
+        by_type = {t.source_type: t.text for t in extract_texts(records)}
+        assert by_type["feedback"] == "Two\nparts"
+        assert by_type["llm"] == "prompt: p1\np2\ncompletion: text: done"
+
+    def test_empty_containers_are_no_text(self):
+        records = [event("job.failed", error_excerpt=[], error={}, message=[[""]])]
+        assert extract_texts(records) == []
+
+    def test_bounded(self):
+        deep: list = ["bottom"]
+        for _ in range(100):
+            deep = [deep]
+        huge = ["x" * 1000] * 10_000
+        records = [event("job.failed", error=deep), event("job.failed", message=huge)]
+        texts = extract_texts(records)
+        assert len(texts) == 1  # the deep one is cut off before any text
+        assert len(texts[0].text) < 70_000
+
+    def test_other_values_use_str(self):
+        [item] = extract_texts([event("job.failed", error=42)])
+        assert item.text == "42"
+
+
+class TestBackfill:
+    async def test_everything_once(self, db):
+        store = db()
+        await store.write(mixed_records())
+        emb = EmbeddingSink(FakeEmbedder(), store)
+        counts = await backfill_embeddings(emb)
+        assert counts == {
+            "feedback": 1,
+            "call_error": 2,
+            "event": 2,
+            "llm": 1,
+            "skipped": 0,
+            "errors": 0,
+        }
+        stored = keyed(await rows(store))
+        texts = {k[0]: [] for k in stored}
+        for (source_type, _), row in stored.items():
+            texts[source_type].append(row["text"])
+        assert sorted(texts["call_error"]) == [
+            "find: TimeoutError: no object Cube",
+            "render: TimeoutError: render timed out after 30s",
+        ]
+        assert texts["feedback"] == ["Render hangs\nat 99%"]
+        assert texts["llm"] == ["prompt: summarize the log\ncompletion: it failed"]
+        assert sorted(texts["event"]) == ["line one\nline two", "rate limited"]
+        assert ("feedback", "bug-1") in stored
+
+    async def test_pre_outcome_error_rows(self, db):
+        store = db()
+        old = error_call(1, message="boom from before outcome existed")
+        old_ok = call_record(outcome="ok")
+        await store.write([old, old_ok])
+        t = store.table
+        async with store.engine.begin() as conn:
+            await conn.execute(update(t).values(outcome=None))
+        emb = EmbeddingSink(FakeEmbedder(), store)
+        counts = await backfill_embeddings(emb)
+        assert counts["call_error"] == 1
+        [row] = await rows(store)
+        assert row["source_id"] == old.id
+        assert row["text"] == "render: TimeoutError: boom from before outcome existed"
+
+    async def test_same_text_hash_and_id_as_live_sink(self, db):
+        records = mixed_records() + [
+            ev(9, "job.failed", error={"zeta": 1, "alpha": {"b": 2, "a": [1, 2]}}),
+        ]
+        backfilled, live = db("backfilled"), db("live")
+        await backfilled.write(records)
+        await backfill_embeddings(EmbeddingSink(FakeEmbedder(), backfilled))
+        live_emb = EmbeddingSink(FakeEmbedder(), live)
+        await live_emb.write(records)
+        await live_emb.flush()
+        assert live_emb.errors == 0
+
+        def shape(stored):
+            return sorted(
+                (r["source_type"], r["source_id"], r["text"], r["text_hash"])
+                for r in stored
+            )
+
+        assert shape(await rows(backfilled)) == shape(await rows(live))
+        assert len(await rows(live)) == 7
+
+    async def test_live_records_dedupe_against_backfill(self, db):
+        records = mixed_records() + [
+            ev(9, "job.failed", error={"zeta": 1, "alpha": {"b": 2, "a": [1, 2]}}),
+        ]
+        store = db()
+        await store.write(records)
+        await backfill_embeddings(EmbeddingSink(FakeEmbedder(), store))
+        before = await count_rows(store)
+        embedder = FakeEmbedder()
+        live = EmbeddingSink(embedder, store)
+        # The records as they come back from the database, as a live sink
+        # in another process would have seen them before storing.
+        await live.write(records)
+        await live.flush()
+        assert embedder.calls == []
+        assert live.embedded == 0 and live.skipped == 7
+        assert await count_rows(store) == before
+
+    async def test_second_run_embeds_nothing(self, db):
+        store = db()
+        await store.write(mixed_records())
+        embedder = FakeEmbedder()
+        emb = EmbeddingSink(embedder, store)
+        await backfill_embeddings(emb)
+        calls = len(embedder.calls)
+        again = await backfill_embeddings(emb)
+        assert again == {
+            "feedback": 0,
+            "call_error": 0,
+            "event": 0,
+            "llm": 0,
+            "skipped": 6,
+            "errors": 0,
+        }
+        assert len(embedder.calls) == calls
+
+    async def test_changed_text_replaces(self, db):
+        store = db()
+        record = error_call(1, message="first")
+        await store.write([record])
+        emb = EmbeddingSink(FakeEmbedder(), store)
+        await backfill_embeddings(emb)
+        async with store.engine.begin() as conn:
+            await conn.execute(
+                update(store.table).values(error_message="second"),
+            )
+        counts = await backfill_embeddings(emb)
+        assert counts["call_error"] == 1
+        [row] = await rows(store)
+        assert row["text"] == "render: TimeoutError: second"
+
+    async def test_sources(self, db):
+        store = db()
+        await store.write(mixed_records())
+        emb = EmbeddingSink(FakeEmbedder(), store)
+        counts = await backfill_embeddings(emb, sources=["feedback", "llm"])
+        assert counts == {"feedback": 1, "llm": 1, "skipped": 0, "errors": 0}
+        assert {r["source_type"] for r in await rows(store)} == {"feedback", "llm"}
+
+    async def test_defaults_to_sink_sources(self, db):
+        store = db()
+        await store.write(mixed_records())
+        emb = EmbeddingSink(FakeEmbedder(), store, sources=["call_error"])
+        counts = await backfill_embeddings(emb)
+        assert counts == {"call_error": 2, "skipped": 0, "errors": 0}
+
+    async def test_since_until(self, db):
+        store = db()
+        await store.write([error_call(m, message=f"error {m}") for m in range(10)])
+        emb = EmbeddingSink(FakeEmbedder(), store)
+        counts = await backfill_embeddings(emb, since=at(3), until=at(6))
+        assert counts["call_error"] == 3
+        texts = sorted(r["text"] for r in await rows(store))
+        assert texts == [f"render: TimeoutError: error {m}" for m in (3, 4, 5)]
+        # A naive datetime is UTC.
+        naive = (T0 + timedelta(minutes=8)).replace(tzinfo=None)
+        counts = await backfill_embeddings(emb, since=naive)
+        assert counts["call_error"] == 2
+
+    async def test_limit_takes_oldest_and_resumes(self, db):
+        store = db()
+        await store.write([error_call(m, message=f"error {m}") for m in range(10)])
+        emb = EmbeddingSink(FakeEmbedder(), store)
+        counts = await backfill_embeddings(emb, limit=4, batch_size=3)
+        assert counts["call_error"] == 4
+        texts = sorted(r["text"] for r in await rows(store))
+        assert texts == [f"render: TimeoutError: error {m}" for m in range(4)]
+        counts = await backfill_embeddings(emb, limit=4, batch_size=3)
+        assert counts["call_error"] == 4 and counts["skipped"] == 4
+        counts = await backfill_embeddings(emb, limit=0)
+        assert counts["call_error"] == 0
+
+    async def test_pages_through_many_rows(self, db):
+        store = db()
+        # Identical timestamps too, so paging must break ties on id.
+        records = [error_call(m // 5, message=f"error {m}") for m in range(53)]
+        records += [ev(m // 5, "job.failed", error=f"job error {m}") for m in range(41)]
+        await store.write(records)
+        embedder = FakeEmbedder()
+        emb = EmbeddingSink(embedder, store, batch_size=8)
+        counts = await backfill_embeddings(emb, batch_size=7)
+        assert counts["call_error"] == 53 and counts["event"] == 41
+        assert await count_rows(store) == 94
+        assert len(embedder.seen) == 94  # nothing read twice
+        assert max(len(c) for c in embedder.calls) <= 8
+
+    async def test_embedder_errors_are_counted(self, db):
+        store = db()
+        await store.write([error_call(m, message=f"error {m}") for m in range(5)])
+        emb = EmbeddingSink(FakeEmbedder(fail=True), store, batch_size=2)
+        counts = await backfill_embeddings(emb)
+        assert counts["errors"] == 5 and counts["call_error"] == 0
+        assert await count_rows(store) == 0
+        emb.embedder.fail = False
+        counts = await backfill_embeddings(emb)
+        assert counts["call_error"] == 5 and counts["errors"] == 0
+
+    async def test_wrong_vector_count_is_counted(self, db):
+        class Short(FakeEmbedder):
+            async def embed(self, texts):
+                return (await super().embed(texts))[:-1]
+
+        store = db()
+        await store.write([error_call(1), error_call(2, message="other")])
+        counts = await backfill_embeddings(EmbeddingSink(Short(), store))
+        assert counts["errors"] == 2
+
+    async def test_redaction(self, db):
+        store = db()
+        leaked = error_call(1, message=f"auth failed with {SECRET}")
+        custom = ev(2, "job.failed", error="ticket ACME-1234 failed")
+        await store.write([leaked, custom])
+        embedder = FakeEmbedder()
+        emb = EmbeddingSink(
+            embedder, store, redactor=Redactor(extra_patterns=[r"ACME-\d+"])
+        )
+        await backfill_embeddings(emb)
+        texts = sorted(r["text"] for r in await rows(store))
+        assert SECRET not in "".join(embedder.seen + texts)
+        assert "ACME-1234" not in "".join(embedder.seen + texts)
+        assert f"render: TimeoutError: auth failed with {REDACTED}" in texts
+        assert f"ticket {REDACTED} failed" in texts
+
+    async def test_truncation(self, db):
+        store = db()
+        await store.write([error_call(1, message="x" * 500)])
+        emb = EmbeddingSink(FakeEmbedder(), store, max_chars=50)
+        await backfill_embeddings(emb)
+        [row] = await rows(store)
+        assert len(row["text"]) == 50
+
+    async def test_dry_run_writes_nothing(self, db):
+        store = db()
+        await store.write(mixed_records())
+        embedder = FakeEmbedder()
+        emb = EmbeddingSink(embedder, store)
+        counts = await backfill_embeddings(emb, dry_run=True)
+        assert counts["call_error"] == 2 and counts["feedback"] == 1
+        assert embedder.calls == []
+        assert await rows(store) == []
+
+    async def test_missing_tables_raise(self, db):
+        store = db(create_tables=False)
+        emb = EmbeddingSink(FakeEmbedder(), store)
+        with pytest.raises(RuntimeError, match="does not exist"):
+            await backfill_embeddings(emb)
+        with pytest.raises(RuntimeError, match="does not exist"):
+            await backfill_embeddings(emb, dry_run=True)
+
+    async def test_bad_arguments(self, db):
+        emb = EmbeddingSink(FakeEmbedder(), db())
+        with pytest.raises(ValueError, match="unknown sources"):
+            await backfill_embeddings(emb, sources=["nope"])
+        with pytest.raises(ValueError):
+            await backfill_embeddings(emb, batch_size=0)
+        with pytest.raises(ValueError):
+            await backfill_embeddings(emb, limit=-1)
+
+
+class TestBackfillFeedback:
+    async def test_matches_feedback_event(self, db):
+        own, events = db("own"), db("events")
+        items = [
+            ("bug-1", " Render hangs ", "Stuck at 99%"),
+            ("bug-2", "No description", None),
+            ("bug-3", "", ""),
+        ]
+        counts = await backfill_feedback(EmbeddingSink(FakeEmbedder(), own), items)
+        assert counts == {"feedback": 2, "skipped": 0, "errors": 0}
+        live = EmbeddingSink(FakeEmbedder(), events)
+        await live.write(
+            [
+                EventRecord(
+                    kind="feedback.submitted",
+                    occurred_at=datetime.now(UTC),
+                    key=ref,
+                    attrs={"title": title, "description": desc},
+                )
+                for ref, title, desc in items
+            ]
+        )
+        await live.flush()
+
+        def shape(stored):
+            return sorted((r["source_id"], r["text"], r["text_hash"]) for r in stored)
+
+        assert shape(await rows(own)) == shape(await rows(events))
+        assert shape(await rows(own))[0][1] == "Render hangs\nStuck at 99%"
+
+    async def test_idempotent_and_dedupes_with_events(self, db):
+        store = db()
+        emb = EmbeddingSink(FakeEmbedder(), store)
+        await backfill_feedback(emb, [("bug-1", "Render hangs", "at 99%")])
+        await store.write(
+            [
+                ev(
+                    1,
+                    "feedback.submitted",
+                    "bug-1",
+                    title="Render hangs",
+                    description="at 99%",
+                )
+            ]
+        )
+        counts = await backfill_embeddings(emb)
+        assert counts["feedback"] == 0 and counts["skipped"] == 1
+        counts = await backfill_feedback(
+            emb, iter([("bug-1", "Render hangs", "at 99%")]), batch_size=1
+        )
+        assert counts == {"feedback": 0, "skipped": 1, "errors": 0}
+
+    async def test_redacted(self, db):
+        store = db()
+        emb = EmbeddingSink(FakeEmbedder(), store)
+        await backfill_feedback(emb, [("bug-1", "Leak", f"my key is {SECRET}")])
+        [row] = await rows(store)
+        assert SECRET not in row["text"] and REDACTED in row["text"]
+
+
+class TestCli:
+    async def seeded(self, db):
+        store = db()
+        await store.write(mixed_records())
+        await store.ensure_embeddings()
+        return store
+
+    async def test_dry_run_main(self, db, capsys):
+        store = await self.seeded(db)
+        url = store.engine.url.render_as_string(hide_password=False)
+        code = await _in_thread(
+            cli_main,
+            [
+                "--database-url",
+                url,
+                "--dim",
+                str(DIM),
+                "--dry-run",
+                "--sources",
+                "call_error,feedback",
+            ],
+        )
+        assert code == 0
+        out = json.loads(capsys.readouterr().out.strip().splitlines()[-1])
+        assert out == {
+            "dry_run": True,
+            "feedback": 1,
+            "call_error": 2,
+            "skipped": 0,
+            "errors": 0,
+        }
+        assert await rows(store) == []
+
+    async def test_dry_run_subprocess(self, db):
+        store = await self.seeded(db)
+        url = store.engine.url.render_as_string(hide_password=False)
+        env = {k: v for k, v in os.environ.items() if k != "FFB_EMBED_API_KEY"}
+        proc = await _in_thread(
+            subprocess.run,
+            [
+                sys.executable,
+                "-m",
+                "fastmcp_feedback.instrumentation.backfill",
+                "--database-url",
+                url,
+                "--dim",
+                str(DIM),
+                "--dry-run",
+            ],
+            capture_output=True,
+            text=True,
+            env=env,
+            timeout=60,
+        )
+        assert proc.returncode == 0, proc.stderr
+        out = json.loads(proc.stdout.strip().splitlines()[-1])
+        assert out["call_error"] == 2 and out["llm"] == 1 and out["event"] == 2
+        assert "RuntimeWarning" not in proc.stderr
+
+    async def test_needs_embed_url_without_dry_run(self, capsys):
+        with pytest.raises(SystemExit) as exc:
+            cli_main(["--database-url", "sqlite+aiosqlite:///x.db"])
+        assert exc.value.code == 2
+        assert "--embed-base-url" in capsys.readouterr().err
+
+    async def test_no_api_key_flag(self, capsys):
+        with pytest.raises(SystemExit):
+            cli_main(["--database-url", "sqlite+aiosqlite:///x.db", "--api-key", "k"])
+
+    async def test_setup_error_exit_code(self, tmp_path, capsys):
+        url = f"sqlite+aiosqlite:///{tmp_path / 'empty.db'}"
+        code = await _in_thread(cli_main, ["--database-url", url, "--dry-run"])
+        assert code == 2
+        assert "does not exist" in capsys.readouterr().err
+
+    async def test_api_key_from_env(self, db, monkeypatch):
+        seen = {}
+
+        class Recorder(FakeEmbedder):
+            def __init__(self, base_url, api_key=None, model="m", dim=DIM, **kw):
+                super().__init__(dim=dim, model=model)
+                seen["api_key"] = api_key
+                seen["base_url"] = base_url
+
+        store = await self.seeded(db)
+        url = store.engine.url.render_as_string(hide_password=False)
+        monkeypatch.setattr(
+            "fastmcp_feedback.instrumentation.backfill.cli.OpenAIEmbedder", Recorder
+        )
+        monkeypatch.setenv("MY_KEY", "secret-value")
+        code = await _in_thread(
+            cli_main,
+            [
+                "--database-url",
+                url,
+                "--dim",
+                str(DIM),
+                "--embed-base-url",
+                "https://embed.example/v1",
+                "--api-key-env",
+                "MY_KEY",
+            ],
+        )
+        assert code == 0
+        assert seen == {
+            "api_key": "secret-value",
+            "base_url": "https://embed.example/v1",
+        }
+        assert await count_rows(store) == 6
+
+
+async def _in_thread(fn, *args, **kwargs):
+    # The CLI runs its own event loop, which cannot start on the test's.
+    import asyncio
+
+    return await asyncio.to_thread(fn, *args, **kwargs)

tests/unit/test_base_install.py

@@ -0,0 +1,90 @@
+"""The instrumentation works on a base install, without the database extras.
+
+The worker runs in a fresh interpreter with greenlet and aiosqlite made
+unimportable, which is what ``pip install fastmcp-feedback`` leaves out.
+"""
+
+import json
+import subprocess
+import sys
+from pathlib import Path
+
+import pytest
+
+WORKER = Path(__file__).parent.parent / "fixtures" / "base_install_worker.py"
+
+
+@pytest.fixture(scope="module")
+def report(tmp_path_factory) -> dict:
+    proc = subprocess.run(
+        [sys.executable, str(WORKER), str(tmp_path_factory.mktemp("base"))],
+        capture_output=True,
+        text=True,
+        timeout=60,
+    )
+    assert proc.returncode == 0, proc.stderr[-4000:]
+    return json.loads(proc.stdout.strip().splitlines()[-1])
+
+
+def test_tool_calls_are_recorded(report):
+    assert report["result"] == "5"
+    assert report["tools"] == ["add", "submit_feedback"]
+    assert report["jsonl_lines"] == 4  # two calls, two events
+
+
+def test_events_are_recorded(report):
+    assert report["event_kinds"] == ["feedback.submitted", "job.done"]
+    assert report["events_for"] == 1
+
+
+def test_feedback_tools_work_alongside(report):
+    assert report["feedback"]["success"] is True
+    assert report["feedback"]["linked_calls"] == 0
+
+
+def test_database_helpers_return_empty_defaults(report):
+    assert report["capture"] == []
+    assert report["similar"] == []
+    assert report["similar_feedback"] == []
+    assert report["feedback_context"] == []
+    assert report["link_feedback"] is False
+    assert report["database_sink"] is True
+    assert report["embedding_sink"] is True
+
+
+def test_constants_import_without_the_extra(report):
+    assert report["prefix"] == "ffb_"
+
+
+def test_storage_modules_stay_unloaded(report):
+    assert report["loaded"] == []
+
+
+@pytest.mark.parametrize(
+    ("name", "extra"),
+    [
+        ("DatabaseSink", "[instrumentation]"),
+        ("build_metadata", "[instrumentation]"),
+        ("EmbeddingSink", "[instrumentation,embeddings]"),
+        ("backfill_feedback", "[instrumentation,embeddings]"),
+    ],
+)
+def test_database_names_explain_the_missing_extra(report, name, extra):
+    # Asked twice: SQLAlchemy reports a missing greenlet only on first import.
+    for message in report["errors"][name]:
+        assert message is not None
+        assert "greenlet" in message
+        assert f'uv add "fastmcp-feedback{extra}"' in message
+
+
+def test_lazy_names_resolve_with_the_extra():
+    import fastmcp_feedback.instrumentation as inst
+    from fastmcp_feedback.instrumentation import DatabaseSink, storage
+
+    assert DatabaseSink is storage.DatabaseSink
+    assert set(inst._LAZY) <= set(inst.__all__)
+    assert set(inst.__all__) <= set(dir(inst))
+    for name in inst.__all__:
+        assert getattr(inst, name) is not None
+    with pytest.raises(AttributeError):
+        _ = inst.not_a_name

tests/unit/test_classifier_paths.py

@@ -0,0 +1,101 @@
+"""soft_error_classifier: message_keys and dotted paths into nested results."""
+
+import pytest
+
+from fastmcp_feedback.instrumentation import soft_error_classifier
+from fastmcp_feedback.instrumentation.classify import MESSAGE_KEYS, lookup
+
+# mcardupilot: a wait that returned because the SITL died, the cause nested.
+SITL = soft_error_classifier(
+    status_keys=("status", "state", "reason"),
+    extra_statuses=("died",),
+    message_keys=("snapshot.error", "error", "message", "detail", "reason"),
+)
+
+
+class TestMcardupilot:
+    def test_died_reads_the_nested_cause(self):
+        result = {"reason": "died", "snapshot": {"error": "SITL exited: segfault"}}
+        assert SITL("wait_until", result) == "reason=died: SITL exited: segfault"
+
+    def test_timeout_stays_ok(self):
+        result = {"reason": "timeout", "snapshot": {"error": None, "alt": 12.0}}
+        assert SITL("wait_until", result) is None
+
+    def test_reached_stays_ok(self):
+        assert SITL("wait_until", {"reason": "reached", "snapshot": {}}) is None
+
+    def test_died_without_a_cause_falls_back(self):
+        assert SITL("wait_until", {"reason": "died"}) == "reason=died: died"
+
+    def test_dead_session_state(self):
+        result = {"state": "died", "error": "lost heartbeat"}
+        assert SITL("snapshot", result) == "state=died: lost heartbeat"
+
+    def test_default_message_keys_cannot_reach_it(self):
+        plain = soft_error_classifier(
+            status_keys=("status", "state", "reason"), extra_statuses=("died",)
+        )
+        result = {"reason": "died", "snapshot": {"error": "SITL exited: segfault"}}
+        assert plain("wait_until", result) == "reason=died: died"
+
+
+class TestLookup:
+    @pytest.mark.parametrize(
+        "result",
+        [
+            {},
+            {"snapshot": None},
+            {"snapshot": "a string"},
+            {"snapshot": ["error"]},
+            {"snapshot": 3},
+            {"snapshot": {}},
+            {"snapshot": {"other": 1}},
+        ],
+    )
+    def test_missing_or_non_dict_step_is_absent(self, result):
+        assert lookup(result, "snapshot.error") is None
+
+    def test_deep_path(self):
+        assert lookup({"a": {"b": {"c": "x"}}}, "a.b.c") == "x"
+
+    def test_literal_dotted_key_wins(self):
+        result = {"snapshot.error": "literal", "snapshot": {"error": "nested"}}
+        assert lookup(result, "snapshot.error") == "literal"
+
+    def test_plain_key(self):
+        assert lookup({"error": "x"}, "error") == "x"
+        assert lookup({"error": None}, "error") is None
+
+    def test_odd_paths_never_raise(self):
+        for key in ("", ".", "a.", ".a", "a..b"):
+            lookup({"a": {"": {"b": 1}}}, key)
+
+
+class TestOptions:
+    def test_default_message_keys(self):
+        assert MESSAGE_KEYS == ("error", "message", "detail", "reason")
+
+    def test_message_keys_order(self):
+        classify = soft_error_classifier(message_keys=("detail", "error"))
+        result = {"status": "failed", "error": "e", "detail": "d"}
+        assert classify("t", result) == "status=failed: d"
+
+    def test_dotted_error_keys(self):
+        classify = soft_error_classifier(error_keys=("result.error",))
+        assert classify("t", {"result": {"error": " broke "}}) == "result.error: broke"
+        assert classify("t", {"result": {"error": ""}}) is None
+        assert classify("t", {"result": "error"}) is None
+
+    def test_dotted_error_keys_respect_explicit_success(self):
+        classify = soft_error_classifier(error_keys=("result.error",))
+        assert classify("t", {"ok": True, "result": {"error": "warn"}}) is None
+
+    def test_nested_dict_message_searched_with_same_keys(self):
+        classify = soft_error_classifier(message_keys=("problem",))
+        result = {"status": "failed", "problem": {"problem": "inner"}}
+        assert classify("t", result) == "status=failed: inner"
+
+    def test_is_error_uses_message_keys(self):
+        classify = soft_error_classifier(message_keys=("why",))
+        assert classify("t", {"isError": True, "why": "nope"}) == "isError: nope"

tests/unit/test_consistency.py

@@ -0,0 +1,524 @@
+"""Statistics labels, event identity and logging, as fixed in 2026.10.01.4.
+
+Statistics run on SQLite and, with FFB_TEST_DATABASE_URL set, on Postgres
+through the feedback tools' own synchronous engine (psycopg2).
+"""
+
+import asyncio
+import contextlib
+import json
+import os
+import subprocess
+import sys
+import tomllib
+from pathlib import Path
+
+import pytest
+from fastmcp import Client, FastMCP
+from fastmcp.exceptions import ToolError
+from packaging.requirements import Requirement
+from sqlalchemy import String, select, text, type_coerce
+from sqlalchemy.engine import make_url
+
+import fastmcp_feedback
+from fastmcp_feedback import (
+    FeedbackDatabase,
+    ManagementMixin,
+    RetrievalMixin,
+    SubmissionMixin,
+    SubmitFeedbackRequest,
+    get_database_stats,
+)
+from fastmcp_feedback.database import enum_label
+from fastmcp_feedback.instrumentation import REDACTED, MemorySink, instrument
+from fastmcp_feedback.models import Feedback, FeedbackStatus, FeedbackType
+
+ROOT = Path(__file__).resolve().parents[2]
+
+
+# Statistics
+
+
+@pytest.fixture
+async def feedback_db(db_backend, db_url):
+    """A FeedbackDatabase on an empty database of the current backend."""
+    url = make_url(db_url("feedback"))
+    if db_backend == "postgres":
+        pytest.importorskip("psycopg2")
+        url = url.set(drivername="postgresql+psycopg2")
+    else:
+        url = url.set(drivername="sqlite")
+    db = FeedbackDatabase(url.render_as_string(hide_password=False))
+    await db.initialize()
+    yield db
+    await db.close()
+
+
+async def seed(db):
+    """Two bugs (one in progress) and a feature, through the tools."""
+    submit = SubmissionMixin(db)
+    ids = []
+    for kind in ("bug", "bug", "feature"):
+        result = await submit.submit_feedback(
+            SubmitFeedbackRequest(
+                type=kind, title=f"a {kind}", description="d", submitter="t"
+            )
+        )
+        assert result["success"], result
+        ids.append(result["feedback_id"])
+    updated = await ManagementMixin(db).update_feedback_status(
+        ids[0], FeedbackStatus.IN_PROGRESS
+    )
+    assert updated["success"], updated
+    return ids
+
+
+class TestStatisticsLabels:
+    async def test_database_stores_enum_names(self, feedback_db):
+        # Why the mapping exists: the columns hold names on both backends.
+        await seed(feedback_db)
+        async with feedback_db.session() as session:
+            stored = session.execute(
+                select(type_coerce(Feedback.type, String)).distinct()
+            ).scalars()
+            assert set(stored) == {"BUG", "FEATURE"}
+
+    async def test_statistics_keyed_by_value(self, feedback_db):
+        await seed(feedback_db)
+        stats = await RetrievalMixin(feedback_db).get_feedback_statistics()
+        assert "error" not in stats, stats
+        assert stats["total_count"] == 3
+        assert stats["by_type"] == {"bug": 2, "feature": 1}
+        assert stats["by_status"] == {"open": 2, "in_progress": 1}
+
+    async def test_statistics_keys_match_list_feedback(self, feedback_db):
+        await seed(feedback_db)
+        retrieval = RetrievalMixin(feedback_db)
+        stats = await retrieval.get_feedback_statistics()
+        listed = (await retrieval.list_feedback(per_page=100))["feedback"]
+        assert set(stats["by_type"]) == {f["type"] for f in listed}
+        assert set(stats["by_status"]) == {f["status"] for f in listed}
+
+    async def test_filter_by_statistics_key(self, feedback_db):
+        await seed(feedback_db)
+        retrieval = RetrievalMixin(feedback_db)
+        stats = await retrieval.get_feedback_statistics()
+        for kind, count in stats["by_type"].items():
+            listed = await retrieval.list_feedback(type_filter=kind)
+            assert listed["total_count"] == count
+
+    async def test_database_stats_keyed_by_value(self, feedback_db):
+        await seed(feedback_db)
+        stats = await get_database_stats(feedback_db)
+        assert stats["by_type"] == {"bug": 2, "feature": 1}
+        assert stats["by_status"] == {"open": 2, "in_progress": 1}
+
+    async def test_empty_database(self, feedback_db):
+        stats = await RetrievalMixin(feedback_db).get_feedback_statistics()
+        assert stats["by_type"] == {} and stats["by_status"] == {}
+
+
+class TestEnumLabel:
+    @pytest.mark.parametrize(
+        ("enum_cls", "stored", "label"),
+        [
+            (FeedbackType, FeedbackType.BUG, "bug"),
+            (FeedbackType, "BUG", "bug"),
+            (FeedbackType, "bug", "bug"),
+            (FeedbackStatus, "IN_PROGRESS", "in_progress"),
+            (FeedbackStatus, "in_progress", "in_progress"),
+            (FeedbackStatus, "archived", "archived"),
+        ],
+    )
+    def test_label(self, enum_cls, stored, label):
+        assert enum_label(enum_cls, stored) == label
+
+    async def test_rows_written_as_values_are_merged(self, tmp_path):
+        # A row holding the value instead of the name (written by hand, or by
+        # another tool) is counted under the same key, not dropped.
+        db = FeedbackDatabase(f"sqlite:///{tmp_path}/legacy.db")
+        await db.initialize()
+        try:
+            await seed(db)
+            async with db.session() as session:
+                session.execute(
+                    text(
+                        "INSERT INTO feedback (type, title, description, submitter,"
+                        " status, created_at, updated_at) VALUES ('bug', 't', 'd',"
+                        " 's', 'open', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)"
+                    )
+                )
+                session.commit()
+            stats = await RetrievalMixin(db).get_feedback_statistics()
+            assert stats["by_type"] == {"bug": 3, "feature": 1}
+            assert stats["by_status"] == {"open": 3, "in_progress": 1}
+        finally:
+            await db.close()
+
+
+# Event identity
+
+
+def make_app(resolver=None, **kwargs):
+    sink = MemorySink()
+    app = FastMCP("identity")
+    holder = {"spawned": []}
+
+    @app.tool
+    async def submit(job_id: str) -> dict:
+        holder["mw"].record_event("job.submitted", key=job_id)
+        return {"job_id": job_id}
+
+    @app.tool
+    def submit_sync(job_id: str) -> dict:
+        holder["mw"].record_event("job.submitted", key=job_id)
+        return {"job_id": job_id}
+
+    @app.tool
+    async def submit_as(job_id: str) -> dict:
+        holder["mw"].record_event(
+            "job.submitted",
+            key=job_id,
+            user_sub="given-user",
+            caller_kind="given-kind",
+            client_id="given-client",
+        )
+        return {"job_id": job_id}
+
+    @app.tool
+    async def chat() -> str:
+        holder["mw"].record_llm_call(model="m", provider="p")
+        return "ok"
+
+    @app.tool
+    async def fails() -> str:
+        holder["mw"].record_event("job.failed")
+        raise RuntimeError("no")
+
+    @app.tool
+    async def spawn(job_id: str) -> dict:
+        """Start a task that records after this call has returned."""
+        started = asyncio.Event()
+
+        async def watcher():
+            started.set()
+            await asyncio.sleep(0.05)
+            holder["mw"].record_event("job.started", key=job_id)
+
+        holder["spawned"].append(asyncio.get_running_loop().create_task(watcher()))
+        await started.wait()
+        return {"job_id": job_id}
+
+    mw = instrument(app, [sink], identity_resolver=resolver, **kwargs)
+    holder["mw"] = mw
+    return app, sink, mw, holder["spawned"]
+
+
+async def call(app, mw, *calls):
+    async with Client(app) as client:
+        for tool, args in calls:
+            with contextlib.suppress(ToolError):
+                await client.call_tool(tool, args)
+    await mw.flush()
+
+
+class Resolver:
+    """Counts its invocations; returns a different user each time."""
+
+    def __init__(self, extra=None):
+        self.calls = 0
+        self.extra = extra or {}
+
+    def __call__(self, context):
+        self.calls += 1
+        return {
+            "user_sub": f"user-{self.calls}",
+            "caller_kind": "pat",
+            "client_id": "addon",
+            "org": "acme",
+            **self.extra,
+        }
+
+
+class AsyncResolver(Resolver):
+    async def __call__(self, context):
+        await asyncio.sleep(0)
+        return Resolver.__call__(self, context)
+
+
+IDENTITY = ("user-1", "pat", "addon")
+
+
+def ident(record):
+    return (record.user_sub, record.caller_kind, record.client_id)
+
+
+class TestEventIdentity:
+    @pytest.mark.parametrize("resolver_cls", [Resolver, AsyncResolver])
+    async def test_event_in_call_gets_resolver_identity(self, resolver_cls):
+        who = resolver_cls()
+        app, sink, mw, _ = make_app(who)
+        await call(app, mw, ("submit", {"job_id": "j1"}))
+        [rec] = sink.calls
+        [ev] = sink.events
+        assert ident(ev) == IDENTITY
+        assert ident(rec) == IDENTITY
+        assert ev.call_id == rec.id
+        assert rec.identity == {"org": "acme"}
+
+    async def test_sync_tool_event_gets_identity(self):
+        app, sink, mw, _ = make_app(Resolver())
+        await call(app, mw, ("submit_sync", {"job_id": "j1"}))
+        await asyncio.sleep(0.01)
+        await mw.flush()
+        [ev] = sink.events
+        assert ident(ev) == IDENTITY
+
+    async def test_llm_call_event_gets_identity(self):
+        app, sink, mw, _ = make_app(Resolver())
+        await call(app, mw, ("chat", {}))
+        [ev] = sink.events
+        assert ev.kind == "llm.call" and ident(ev) == IDENTITY
+
+    async def test_failing_call_event_and_record_share_identity(self):
+        app, sink, mw, _ = make_app(Resolver())
+        await call(app, mw, ("fails", {}))
+        [rec] = sink.calls
+        [ev] = sink.events
+        assert rec.outcome == "error"
+        assert ident(ev) == ident(rec) == IDENTITY
+
+    async def test_resolver_runs_once_per_call(self):
+        who = Resolver()
+        app, sink, mw, _ = make_app(who)
+        await call(
+            app,
+            mw,
+            ("submit", {"job_id": "a"}),
+            ("chat", {}),
+            ("fails", {}),
+            ("submit", {"job_id": "b"}),
+        )
+        assert who.calls == 4
+        assert [r.user_sub for r in sink.calls] == [
+            "user-1",
+            "user-2",
+            "user-3",
+            "user-4",
+        ]
+        # Each event carries its own call's identity.
+        assert [(e.user_sub, e.call_id) for e in sink.events] == [
+            (r.user_sub, r.id) for r in sink.calls
+        ]
+
+    async def test_explicit_identity_wins(self):
+        app, sink, mw, _ = make_app(Resolver())
+        await call(app, mw, ("submit_as", {"job_id": "j1"}))
+        [ev] = sink.events
+        assert ident(ev) == ("given-user", "given-kind", "given-client")
+        assert ident(sink.calls[0]) == IDENTITY
+
+    async def test_task_after_call_gets_no_identity(self):
+        who = Resolver()
+        app, sink, mw, spawned = make_app(who)
+        await call(app, mw, ("spawn", {"job_id": "j1"}))
+        await asyncio.gather(*spawned)
+        await mw.flush()
+        [rec] = sink.calls
+        [ev] = sink.events
+        assert ident(rec) == IDENTITY
+        assert ev.kind == "job.started"
+        assert ev.call_id is None and ev.session_id is None
+        assert ident(ev) == (None, None, None)
+        assert who.calls == 1
+
+    async def test_outside_call_unchanged(self):
+        who = Resolver()
+        app, sink, mw, _ = make_app(who)
+        mw.record_event("job.finished", key="j1")
+        mw.record_event("job.finished", key="j2", user_sub="u9", client_id="c9")
+        await mw.flush()
+        first, second = sink.events
+        assert ident(first) == (None, None, None) and first.call_id is None
+        assert ident(second) == ("u9", None, "c9")
+        assert who.calls == 0
+
+    async def test_identity_redacted_for_events(self):
+        token = "bmcp_abcdefgh12345678"
+        app, sink, mw, _ = make_app(Resolver({"caller_kind": f"pat:{token}"}))
+        await call(app, mw, ("submit", {"job_id": "j1"}))
+        [ev] = sink.events
+        assert ev.caller_kind == f"pat:{REDACTED}"
+        assert sink.calls[0].caller_kind == f"pat:{REDACTED}"
+
+    async def test_failing_resolver_leaves_identity_empty(self):
+        calls = []
+
+        def boom(context):
+            calls.append(1)
+            raise RuntimeError("resolver bug")
+
+        app, sink, mw, _ = make_app(boom)
+        await call(app, mw, ("submit", {"job_id": "j1"}))
+        [rec] = sink.calls
+        [ev] = sink.events
+        assert rec.ok and ev.call_id == rec.id
+        assert ev.user_sub is None and rec.user_sub is None
+        # An empty first answer gets a second run after the tool; it fails too.
+        assert calls == [1, 1]
+
+    async def test_slow_resolver_cut_off_before_tool(self):
+        async def slow(context):
+            await asyncio.sleep(5)
+            return {"user_sub": "late"}
+
+        app, sink, mw, _ = make_app(slow, hook_timeout=0.05)
+        await call(app, mw, ("submit", {"job_id": "j1"}))
+        [rec] = sink.calls
+        [ev] = sink.events
+        assert rec.user_sub is None and ev.user_sub is None and rec.ok
+
+    async def test_mode_off_runs_no_resolver(self):
+        who = Resolver()
+        app, sink, mw, _ = make_app(who, mode="off")
+        await call(app, mw, ("submit", {"job_id": "j1"}))
+        assert who.calls == 0 and sink.calls == [] and sink.events == []
+
+    async def test_excluded_tool_runs_no_resolver(self):
+        who = Resolver()
+        app, sink, mw, _ = make_app(who, exclude_tools={"submit"})
+        await call(app, mw, ("submit", {"job_id": "j1"}))
+        [ev] = sink.events
+        assert who.calls == 0 and ev.user_sub is None and ev.call_id is None
+
+
+# Logging
+
+
+def run_python(code, *args, env=None):
+    return subprocess.run(
+        [sys.executable, "-c", code, *args],
+        capture_output=True,
+        text=True,
+        timeout=60,
+        env=env,
+    )
+
+
+class TestLogging:
+    def test_import_configures_nothing_and_prints_nothing(self):
+        proc = run_python(
+            # FastMCP 2.x and 3.0 reset warning filters on import and authlib
+            # then warns; drop warnings so stderr holds only logging output.
+            "import warnings\nwarnings.showwarning = lambda *a, **k: None\n"
+            "import logging, fastmcp_feedback, fastmcp_feedback.instrumentation\n"
+            "root = logging.getLogger()\n"
+            "print(len(root.handlers), root.level)\n"
+            "print([type(h).__name__ for h in"
+            " logging.getLogger('fastmcp_feedback').handlers])\n"
+        )
+        assert proc.returncode == 0, proc.stderr
+        assert proc.stderr == ""
+        handlers, names = proc.stdout.splitlines()
+        assert handlers == f"0 {30}"  # no handler, level still WARNING
+        assert names == "['NullHandler']"
+
+    def test_import_logs_nothing_above_debug(self):
+        # A host that set up logging first sees only the DEBUG line.
+        proc = run_python(
+            "import logging, json\n"
+            "seen = []\n"
+            "class H(logging.Handler):\n"
+            "    def emit(self, r):\n"
+            "        if r.name.startswith('fastmcp_feedback'):\n"
+            "            seen.append((r.levelname, r.getMessage()))\n"
+            "logging.basicConfig(level=logging.DEBUG, handlers=[H()])\n"
+            "import fastmcp_feedback\n"
+            "print(json.dumps(seen))\n"
+        )
+        assert proc.returncode == 0, proc.stderr
+        seen = json.loads(proc.stdout.splitlines()[-1])
+        assert [level for level, _ in seen] == ["DEBUG"]
+        assert "initialized" in seen[0][1]
+
+    def test_setup_logging_is_opt_in(self):
+        proc = run_python("import fastmcp_feedback\nfastmcp_feedback.setup_logging()\n")
+        assert proc.returncode == 0
+        assert "fastmcp_feedback - INFO - FastMCP Feedback v" in proc.stderr
+
+    def test_package_info_matches_pyproject(self):
+        pyproject = ROOT / "pyproject.toml"
+        if not pyproject.exists():
+            pytest.skip("not running from a source checkout")
+        project = tomllib.loads(pyproject.read_text())["project"]
+        info = fastmcp_feedback.PACKAGE_INFO
+        assert info["version"] == fastmcp_feedback.__version__ == project["version"]
+
+        def reqs(items):
+            return {str(Requirement(r)) for r in items}
+
+        assert reqs(info["dependencies"]) == reqs(project["dependencies"])
+        extras = project["optional-dependencies"]
+        assert set(info["optional_dependencies"]) == set(extras)
+        for name, items in extras.items():
+            if any(r.startswith("fastmcp-feedback") for r in items):
+                continue  # self-references are expanded in the metadata
+            assert reqs(info["optional_dependencies"][name]) == reqs(items), name
+        assert info["classifiers"] == sorted(project["classifiers"])
+
+
+class TestBackfillCliLogging:
+    @pytest.fixture
+    def stored_db(self, tmp_path):
+        """A calls database with one error, written by the CLI's own sink."""
+        url = f"sqlite+aiosqlite:///{tmp_path}/calls.db"
+        code = (
+            "import asyncio, sys\n"
+            "from datetime import UTC, datetime\n"
+            "from fastmcp_feedback.instrumentation import DatabaseSink,"
+            " ToolCallRecord\n"
+            "async def main():\n"
+            "    sink = DatabaseSink(sys.argv[1], create_tables=True)\n"
+            "    await sink.write([ToolCallRecord(tool='t',"
+            " started_at=datetime.now(UTC), duration_ms=1, ok=False,"
+            " outcome='error', mode='meta', error_type='E',"
+            " error_message='broke')])\n"
+            "    await sink.ensure_embeddings()\n"
+            "    await sink.engine.dispose()\n"
+            "asyncio.run(main())\n"
+        )
+        proc = run_python(code, url)
+        assert proc.returncode == 0, proc.stderr
+        return url
+
+    def backfill(self, url, *flags):
+        env = {k: v for k, v in os.environ.items() if k != "FFB_EMBED_API_KEY"}
+        return subprocess.run(
+            [
+                sys.executable,
+                "-m",
+                "fastmcp_feedback.instrumentation.backfill",
+                "--database-url",
+                url,
+                "--dry-run",
+                *flags,
+            ],
+            capture_output=True,
+            text=True,
+            env=env,
+            timeout=60,
+        )
+
+    def test_verbose_logs_at_info(self, stored_db):
+        proc = self.backfill(stored_db, "-v")
+        assert proc.returncode == 0, proc.stderr
+        assert "INFO fastmcp_feedback.instrumentation.backfill: Backfill dry run" in (
+            proc.stderr
+        )
+        assert json.loads(proc.stdout.splitlines()[-1])["call_error"] == 1
+
+    def test_quiet_without_verbose(self, stored_db):
+        proc = self.backfill(stored_db)
+        assert proc.returncode == 0, proc.stderr
+        assert "INFO" not in proc.stderr
+        assert "initialized" not in proc.stderr

tests/unit/test_correlation.py

@@ -0,0 +1,416 @@
+"""Tests for linking feedback to the tool calls that preceded it."""
+
+import asyncio
+import contextlib
+import json
+import sys
+from datetime import UTC, datetime, timedelta
+from pathlib import Path
+
+import fastmcp
+import pytest
+from fastmcp import Client, Context, FastMCP
+from fastmcp.client.transports import PythonStdioTransport
+from fastmcp.exceptions import ToolError
+
+from fastmcp_feedback import add_feedback_tools
+from fastmcp_feedback.instrumentation import (
+    DatabaseSink,
+    MemorySink,
+    instrument,
+)
+from fastmcp_feedback.instrumentation import middleware as mw_module
+from fastmcp_feedback.instrumentation.correlation import (
+    RULE_SESSION,
+    RULE_USER_WINDOW,
+    Candidate,
+    select_calls,
+)
+
+NOW = datetime(2026, 9, 27, 12, 0, tzinfo=UTC)
+
+# FastMCP 4's Client speaks MCP 2026-07-28, which has no sessions, so each
+# in-memory call gets a new ctx.session_id and there is no header or stdio
+# signal to fall back on. Calls from one test client link by user instead.
+FASTMCP_4 = int(fastmcp.__version__.split(".")[0]) >= 4
+SAME_CLIENT_RULE = RULE_USER_WINDOW if FASTMCP_4 else RULE_SESSION
+
+
+@pytest.fixture
+async def db(db_url):
+    """Make DatabaseSinks whose engines are always disposed, even on failure.
+
+    An undisposed aiosqlite engine keeps a worker thread alive and the test
+    process never exits.
+    """
+    made = []
+
+    def factory(name="calls", cls=DatabaseSink):
+        sink = cls(db_url(name), create_tables=True)
+        made.append(sink)
+        return sink
+
+    yield factory
+    for sink in made:
+        await sink.engine.dispose()
+
+
+def cand(id, minutes_ago, session="s1", user="u1", tool="t", ok=True):
+    return Candidate(id, tool, NOW - timedelta(minutes=minutes_ago), ok, session, user)
+
+
+class TestSelectCalls:
+    def test_session_first_then_user_window_chronological(self):
+        links = select_calls(
+            [cand("a", 1), cand("b", 3, session="s2"), cand("c", 2)],
+            session_id="s1",
+            user_sub="u1",
+            since=NOW - timedelta(minutes=15),
+            limit=10,
+        )
+        assert [(link.call_id, link.rule, link.position) for link in links] == [
+            ("b", RULE_USER_WINDOW, 0),
+            ("c", RULE_SESSION, 1),
+            ("a", RULE_SESSION, 2),
+        ]
+
+    def test_session_matches_take_priority_over_newer_user_calls(self):
+        links = select_calls(
+            [cand("old", 10), cand("new", 1, session="s2")],
+            session_id="s1",
+            user_sub="u1",
+            since=NOW - timedelta(minutes=15),
+            limit=1,
+        )
+        assert [(link.call_id, link.rule) for link in links] == [("old", RULE_SESSION)]
+
+    def test_user_window_excludes_old_calls_and_other_users(self):
+        links = select_calls(
+            [
+                cand("recent", 5, session="s2"),
+                cand("stale", 30, session="s2"),
+                cand("other", 1, session="s3", user="u2"),
+            ],
+            session_id="s9",
+            user_sub="u1",
+            since=NOW - timedelta(minutes=15),
+            limit=10,
+        )
+        assert [link.call_id for link in links] == ["recent"]
+
+    def test_limit_keeps_the_most_recent(self):
+        links = select_calls(
+            [cand(str(i), i) for i in range(10)],
+            session_id="s1",
+            user_sub=None,
+            since=NOW,
+            limit=3,
+        )
+        assert [link.call_id for link in links] == ["2", "1", "0"]
+
+    def test_duplicates_counted_once_and_naive_times_treated_as_utc(self):
+        naive = Candidate(
+            "a",
+            "t",
+            (NOW - timedelta(minutes=1)).replace(tzinfo=None),
+            True,
+            "s1",
+            "u1",
+        )
+        links = select_calls(
+            [naive, cand("a", 1)], session_id="s1", user_sub=None, since=NOW, limit=5
+        )
+        assert len(links) == 1 and links[0].started_at.tzinfo is not None
+
+    def test_no_session_or_user_means_no_links(self):
+        assert (
+            select_calls(
+                [cand("a", 1)], session_id=None, user_sub=None, since=NOW, limit=5
+            )
+            == []
+        )
+
+
+def build(sinks=None, user="u1", **kwargs):
+    app = FastMCP("correlated")
+
+    @app.tool
+    def echo(text: str) -> str:
+        return text
+
+    @app.tool
+    def render(scene: str) -> str:
+        raise RuntimeError(f"render of {scene} hung")
+
+    captured = {}
+
+    @app.tool
+    async def report(ctx: Context) -> list:
+        links = await mw.capture_recent_calls(ctx)
+        captured["links"] = links
+        return [link.call_id for link in links]
+
+    identity = {"user": user}
+    mw = instrument(
+        app,
+        sinks if sinks is not None else [MemorySink()],
+        identity_resolver=lambda c: {"user_sub": identity["user"]},
+        **kwargs,
+    )
+    return app, mw, captured, identity
+
+
+class TestCaptureRecentCalls:
+    async def test_same_session_calls_including_failures(self):
+        app, mw, captured, _ = build()
+        async with Client(app) as client:
+            await client.call_tool("echo", {"text": "a"})
+            with contextlib.suppress(ToolError):
+                await client.call_tool("render", {"scene": "castle"})
+            await client.call_tool("report", {})
+
+        links = captured["links"]
+        assert [(link.tool, link.ok, link.rule) for link in links] == [
+            ("echo", True, SAME_CLIENT_RULE),
+            ("render", False, SAME_CLIENT_RULE),
+        ]
+
+    async def test_new_session_per_call_falls_back_to_user_window(self):
+        """PAT/CI clients open a new MCP session for every call."""
+        app, mw, captured, _ = build()
+        for text in ("one", "two"):
+            async with Client(app) as client:
+                await client.call_tool("echo", {"text": text})
+        async with Client(app) as client:
+            await client.call_tool("report", {})
+
+        assert [link.rule for link in captured["links"]] == [RULE_USER_WINDOW] * 2
+
+    async def test_other_users_calls_are_not_linked(self):
+        app, mw, captured, identity = build()
+        identity["user"] = "someone-else"
+        async with Client(app) as client:
+            await client.call_tool("echo", {"text": "not mine"})
+        identity["user"] = "u1"
+        async with Client(app) as client:
+            await client.call_tool("report", {})
+        assert captured["links"] == []
+
+    async def test_calls_still_queued_are_found(self):
+        release = asyncio.Event()
+
+        class Stalled:
+            async def write(self, records):
+                await release.wait()
+
+        app, mw, captured, _ = build(sinks=[Stalled()])
+        async with Client(app) as client:
+            await client.call_tool("echo", {"text": "queued"})
+            await client.call_tool("report", {})
+        release.set()
+        assert [link.tool for link in captured["links"]] == ["echo"]
+
+    async def test_database_fallback_after_restart(self, db):
+        app1, mw1, _, _ = build(sinks=[db("restart")])
+        async with Client(app1) as client:
+            await client.call_tool("echo", {"text": "before restart"})
+        await mw1.aclose()
+
+        # A new process: empty in-memory buffer, same database.
+        app2, mw2, captured, _ = build(sinks=[db("restart")])
+        async with Client(app2) as client:
+            await client.call_tool("report", {})
+        await mw2.aclose()
+
+        [link] = captured["links"]
+        assert link.tool == "echo" and link.rule == RULE_USER_WINDOW
+
+    @pytest.mark.skipif(
+        FASTMCP_4, reason="FastMCP 4 Client is sessionless (MCP 2026-07-28)"
+    )
+    async def test_failing_resolver_still_links_by_session(self):
+        app, mw, captured, _ = build()
+        mw.identity_resolver = lambda c: 1 / 0
+        async with Client(app) as client:
+            await client.call_tool("echo", {"text": "a"})
+            await client.call_tool("report", {})
+        assert [link.rule for link in captured["links"]] == [RULE_SESSION]
+
+    async def test_slow_database_is_skipped(self, db):
+        class SlowDb(DatabaseSink):
+            async def recent_calls(self, **kwargs):
+                await asyncio.sleep(5)
+                return []
+
+        sink = db("slow", SlowDb)
+        app, mw, captured, _ = build(sinks=[sink], correlation_timeout=0.05)
+        async with Client(app) as client:
+            await client.call_tool("echo", {"text": "a"})
+            await client.call_tool("report", {})
+        await mw.aclose()
+        # The lookup timed out, so capture returned [] rather than hanging.
+        assert captured["links"] == []
+
+    async def test_outside_a_tool_call_returns_empty(self):
+        _, mw, _, _ = build()
+        mw.identity_resolver = None
+        assert await mw.capture_recent_calls() == []
+
+
+class TestLinksAndContext:
+    async def test_link_and_read_back_with_external_ids(self, db):
+        sink = db("links")
+        app, mw, captured, _ = build(sinks=[sink])
+        async with Client(app) as client:
+            await client.call_tool("echo", {"text": "a"})
+            with contextlib.suppress(ToolError):
+                await client.call_tool("render", {"scene": "castle"})
+            await client.call_tool("report", {})
+
+        assert await mw.link_feedback("bug-7Q2X", captured["links"])
+        await mw.flush()
+        context = await mw.feedback_context("bug-7Q2X")
+        await mw.aclose()
+
+        assert [(c["position"], c["tool"], c["ok"], c["rule"]) for c in context] == [
+            (0, "echo", True, SAME_CLIENT_RULE),
+            (1, "render", False, SAME_CLIENT_RULE),
+        ]
+        assert context[1]["error_type"] == "RuntimeError"
+
+    async def test_relinking_replaces_links(self, db):
+        sink = db("relink")
+        app, mw, captured, _ = build(sinks=[sink])
+        async with Client(app) as client:
+            await client.call_tool("echo", {"text": "a"})
+            await client.call_tool("report", {})
+        links = captured["links"]
+        await mw.link_feedback("fb-1", links)
+        await mw.link_feedback("fb-1", links)
+        assert len(await mw.feedback_context("fb-1")) == 1
+        await mw.aclose()
+
+    async def test_context_fills_unflushed_calls_from_memory(self, db):
+        release = asyncio.Event()
+
+        class StalledDb(DatabaseSink):
+            async def write(self, records):
+                await release.wait()
+
+        sink = db("unflushed", StalledDb)
+        app, mw, captured, _ = build(sinks=[sink])
+        async with Client(app) as client:
+            await client.call_tool("echo", {"text": "a"})
+            await client.call_tool("report", {})
+        await mw.link_feedback("fb-2", captured["links"])
+
+        [row] = await mw.feedback_context("fb-2")
+        release.set()
+        await mw.aclose()
+        assert row["tool"] == "echo" and row["ok"] is True
+
+    async def test_link_without_database_sink_is_false(self):
+        _, mw, _, _ = build()
+        assert await mw.link_feedback("x", []) is False
+        assert await mw.feedback_context("x") == []
+
+
+class TestSubmitFeedbackAutoLinks:
+    async def test_submission_links_preceding_calls(self, db):
+        app = FastMCP("app")
+
+        @app.tool
+        def render(scene: str) -> str:
+            raise RuntimeError("hung")
+
+        sink = db("submit")
+        mw = instrument(app, [sink], identity_resolver=lambda c: {"user_sub": "u1"})
+        add_feedback_tools(app, database_url="sqlite:///:memory:", instrumentation=mw)
+
+        async with Client(app) as client:
+            with contextlib.suppress(ToolError):
+                await client.call_tool("render", {"scene": "castle"})
+            result = await client.call_tool(
+                "submit_feedback",
+                {
+                    "request": {
+                        "type": "bug",
+                        "title": "render hangs",
+                        "description": "the render tool hung",
+                        "submitter": "model",
+                    }
+                },
+            )
+
+        assert result.data["linked_calls"] == 1
+        await mw.flush()
+        [row] = await mw.feedback_context(result.data["feedback_id"])
+        await mw.aclose()
+        assert (row["tool"], row["ok"], row["error_type"]) == (
+            "render",
+            False,
+            "RuntimeError",
+        )
+
+    async def test_without_instrumentation_response_unchanged(self):
+        app = FastMCP("plain")
+        add_feedback_tools(app, database_url="sqlite:///:memory:")
+        async with Client(app) as client:
+            result = await client.call_tool(
+                "submit_feedback",
+                {
+                    "request": {
+                        "type": "bug",
+                        "title": "t",
+                        "description": "no instrumentation",
+                        "submitter": "m",
+                    }
+                },
+            )
+        assert "linked_calls" not in result.data
+
+
+class FakeContext:
+    def __init__(self, transport=None, session_id="ctx-session"):
+        self.transport = transport
+        self.session_id = session_id
+
+
+class TestSessionKey:
+    def test_http_session_header_wins(self, monkeypatch):
+        import fastmcp.server.dependencies as deps
+
+        monkeypatch.setattr(
+            deps,
+            "get_http_headers",
+            lambda include_all=False: {"mcp-session-id": "hdr-1"},
+        )
+        assert (
+            mw_module.session_key(FakeContext(transport="streamable-http")) == "hdr-1"
+        )
+
+    def test_stdio_uses_one_key_per_process(self):
+        a = mw_module.session_key(FakeContext(transport="stdio", session_id="x"))
+        b = mw_module.session_key(FakeContext(transport="stdio", session_id="y"))
+        assert a == b and a.startswith("stdio:")
+
+    def test_falls_back_to_ctx_session_id(self):
+        assert mw_module.session_key(FakeContext()) == "ctx-session"
+
+    def test_no_context(self):
+        assert mw_module.session_key(None) is None
+
+
+class TestStdioEndToEnd:
+    async def test_same_stdio_client_links_by_session(self):
+        """On a real stdio transport, one client's calls link by session on every FastMCP version."""
+        server = (
+            Path(__file__).parent.parent / "fixtures" / "stdio_correlation_server.py"
+        )
+        transport = PythonStdioTransport(str(server), python_cmd=sys.executable)
+        async with Client(transport) as client:
+            await client.call_tool("echo", {"text": "a"})
+            await client.call_tool("echo", {"text": "b"})
+            result = await client.call_tool("report", {})
+        pairs = json.loads(result.content[0].text)
+        assert pairs == [["echo", RULE_SESSION], ["echo", RULE_SESSION]]

tests/unit/test_create_tables_race.py

@@ -0,0 +1,162 @@
+"""create_tables=True when several processes start against the same empty database.
+
+Both processes see the tables missing and both CREATE them; one fails. The
+sink retries create_all once, which skips what the other process made.
+"""
+
+import json
+import subprocess
+import sys
+from pathlib import Path
+
+import pytest
+from sqlalchemy import create_engine, func, select
+from sqlalchemy.exc import OperationalError
+
+from fastmcp_feedback.instrumentation import (
+    DatabaseSink,
+    InstrumentationMiddleware,
+    build_metadata,
+)
+
+EVENTS = build_metadata().tables["ffb_events"]
+WORKER = Path(__file__).parent.parent / "fixtures" / "create_tables_race_worker.py"
+
+
+def _already_exists():
+    return OperationalError(
+        "CREATE TABLE ffb_tool_calls",
+        {},
+        Exception("table ffb_tool_calls already exists"),
+    )
+
+
+def race(url: str, trigger: Path, workers: int = 2, events: int = 20) -> list[dict]:
+    """Start the workers, release them together, return their JSON results."""
+    procs = [
+        subprocess.Popen(
+            [sys.executable, str(WORKER), url, str(trigger), str(events)],
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            text=True,
+        )
+        for _ in range(workers)
+    ]
+    try:
+        for p in procs:
+            assert p.stdout.readline().strip() == "ready"
+        trigger.touch()
+        results = []
+        for p in procs:
+            out, err = p.communicate(timeout=30)
+            assert p.returncode == 0, err
+            results.append(json.loads(out.strip().splitlines()[-1]))
+        return results
+    finally:
+        for p in procs:
+            if p.poll() is None:
+                p.kill()
+                p.wait()
+
+
+@pytest.mark.slow
+def test_two_processes_cold_start(tmp_path):
+    workers, events = 2, 20
+    for run in range(5):
+        db = tmp_path / f"shared{run}.db"
+        results = race(
+            f"sqlite+aiosqlite:///{db}", tmp_path / f"go{run}", workers, events
+        )
+        engine = create_engine(f"sqlite:///{db}")
+        try:
+            with engine.connect() as conn:
+                stored = conn.execute(
+                    select(func.count()).select_from(EVENTS)
+                ).scalar_one()
+        finally:
+            engine.dispose()
+        assert [r["sink_errors"] for r in results] == [0] * workers, f"run {run}"
+        assert stored == workers * events, f"run {run}"
+
+
+@pytest.fixture
+async def sink(tmp_path):
+    s = DatabaseSink(f"sqlite+aiosqlite:///{tmp_path}/calls.db", create_tables=True)
+    yield s
+    await s.engine.dispose()
+
+
+class TestEnsureTablesRetry:
+    async def test_first_create_fails_retry_succeeds(self, sink, monkeypatch, caplog):
+        real = sink.metadata.create_all
+        calls = []
+
+        def create_all(bind, **kwargs):
+            calls.append(1)
+            if len(calls) == 1:
+                raise _already_exists()
+            return real(bind, **kwargs)
+
+        monkeypatch.setattr(sink.metadata, "create_all", create_all)
+        mw = InstrumentationMiddleware([sink])
+        caplog.set_level("DEBUG", logger="fastmcp_feedback.instrumentation.storage")
+        assert mw.record_event("a.b", key="k") is True
+        await mw.flush()
+        assert mw.dispatcher.sink_errors == 0
+        assert len(calls) == 2
+        assert sink._tables_ready
+        async with sink.engine.connect() as conn:
+            count = (
+                await conn.execute(select(func.count()).select_from(sink.events))
+            ).scalar_one()
+        assert count == 1
+        retry_logs = [r for r in caplog.records if "retry succeeded" in r.getMessage()]
+        assert retry_logs and all(r.levelname == "INFO" for r in retry_logs)
+        assert not [
+            r
+            for r in caplog.records
+            if r.levelname == "WARNING" and r.name.endswith("storage")
+        ]
+
+    async def test_persistent_failure_surfaces(self, sink, monkeypatch):
+        calls = []
+
+        def create_all(bind, **kwargs):
+            calls.append(1)
+            raise _already_exists()
+
+        monkeypatch.setattr(sink.metadata, "create_all", create_all)
+        mw = InstrumentationMiddleware([sink])
+        assert mw.record_event("a.b") is True
+        await mw.flush()
+        assert mw.dispatcher.sink_errors == 1
+        assert len(calls) == 2
+        assert not sink._tables_ready
+        # The next batch tries again rather than assuming the tables exist.
+        assert mw.record_event("a.c") is True
+        await mw.flush()
+        assert mw.dispatcher.sink_errors == 2
+        assert len(calls) == 4
+        await mw.aclose()
+
+    async def test_non_database_error_not_retried(self, sink, monkeypatch):
+        calls = []
+
+        def create_all(bind, **kwargs):
+            calls.append(1)
+            raise RuntimeError("bug")
+
+        monkeypatch.setattr(sink.metadata, "create_all", create_all)
+        with pytest.raises(RuntimeError):
+            await sink.ensure_tables()
+        assert len(calls) == 1
+
+    async def test_create_tables_false_never_creates(self, tmp_path, monkeypatch):
+        s = DatabaseSink(f"sqlite+aiosqlite:///{tmp_path}/none.db")
+        calls = []
+        monkeypatch.setattr(s.metadata, "create_all", lambda *a, **k: calls.append(1))
+        try:
+            await s._ready()
+        finally:
+            await s.engine.dispose()
+        assert calls == []

tests/unit/test_database_advanced.py

@@ -140,10 +140,10 @@ class TestDatabaseAdvancedOperations:
         stats = await get_database_stats(db)
         
         assert stats["total_count"] == 2
-        assert stats["by_type"]["BUG"] == 1
-        assert stats["by_type"]["FEATURE"] == 1
-        assert stats["by_status"]["OPEN"] == 1
-        assert stats["by_status"]["RESOLVED"] == 1
+        assert stats["by_type"]["bug"] == 1
+        assert stats["by_type"]["feature"] == 1
+        assert stats["by_status"]["open"] == 1
+        assert stats["by_status"]["resolved"] == 1
         assert stats["database_url"] == db.database_url
         assert stats["is_initialized"] is True
         
@@ -629,7 +629,7 @@ class TestDatabasePerformanceAndLimits:
         stats = await get_database_stats(db)
         assert stats["total_count"] == 1000
         assert len(stats["by_type"]) >= 1
-        assert stats["by_type"]["IMPROVEMENT"] == 1000
+        assert stats["by_type"]["improvement"] == 1000
         
         await db.close()
     

tests/unit/test_embeddings.py

@@ -0,0 +1,848 @@
+"""Tests for EmbeddingSink, OpenAIEmbedder and similarity search.
+
+DB tests take the ``db_url`` fixture, so they run on SQLite and, with
+FFB_TEST_DATABASE_URL set, on Postgres with pgvector.
+"""
+
+import asyncio
+import contextlib
+import hashlib
+import json
+import logging
+import math
+import os
+import re
+import time
+import uuid
+from datetime import UTC, datetime, timedelta
+
+import pytest
+from fastmcp import Client, FastMCP
+from fastmcp.exceptions import ToolError
+from sqlalchemy import func, select, text, update
+
+from fastmcp_feedback import add_feedback_tools
+from fastmcp_feedback.instrumentation import (
+    REDACTED,
+    DatabaseSink,
+    EmbeddingSink,
+    EventRecord,
+    OpenAIEmbedder,
+    Redactor,
+    ToolCallRecord,
+    build_metadata,
+    extract_texts,
+    instrument,
+)
+from fastmcp_feedback.instrumentation.embeddings import cosine_score
+
+DIM = 256
+SECRET = "sk-abcdefghijklmnopqrstuvwx"
+
+
+def token_vector(text_: str, dim: int = DIM) -> list[float]:
+    """Bag of hashed words, normalized: texts sharing words are close."""
+    v = [0.0] * dim
+    for tok in re.findall(r"[a-z0-9]+", text_.lower()):
+        h = int.from_bytes(hashlib.sha256(tok.encode()).digest()[:4], "big")
+        v[h % dim] += 1.0
+    n = math.sqrt(sum(x * x for x in v)) or 1.0
+    return [x / n for x in v]
+
+
+class FakeEmbedder:
+    def __init__(
+        self,
+        dim=DIM,
+        model="fake-embed",
+        *,
+        fail=False,
+        delay=0.0,
+        gate=None,
+        out_dim=None,
+    ):
+        self.dim = dim
+        self.model = model
+        self.fail = fail
+        self.delay = delay
+        self.gate = gate
+        self.out_dim = out_dim or dim
+        self.calls: list[list[str]] = []
+
+    @property
+    def seen(self) -> list[str]:
+        return [t for batch in self.calls for t in batch]
+
+    async def embed(self, texts):
+        self.calls.append(list(texts))
+        if self.gate is not None:
+            await self.gate.wait()
+        if self.delay:
+            await asyncio.sleep(self.delay)
+        if self.fail:
+            raise RuntimeError("embedding backend down")
+        return [token_vector(t, self.out_dim) for t in texts]
+
+
+@pytest.fixture
+async def db(db_url):
+    made = []
+
+    def factory(name="calls", **kwargs):
+        kwargs.setdefault("create_tables", True)
+        kwargs.setdefault("embedding_dim", DIM)
+        sink = DatabaseSink(db_url(name), **kwargs)
+        made.append(sink)
+        return sink
+
+    yield factory
+    for sink in made:
+        await sink.engine.dispose()
+
+
+def call_record(tool="render", outcome="error", message="render timed out", **kw):
+    return ToolCallRecord(
+        tool=tool,
+        started_at=datetime.now(UTC),
+        duration_ms=1.0,
+        ok=outcome == "ok",
+        outcome=outcome,
+        mode="meta",
+        error_type=None if outcome == "ok" else kw.pop("error_type", "TimeoutError"),
+        error_message=None if outcome == "ok" else message,
+        **kw,
+    )
+
+
+def event(kind, key=None, **attrs):
+    return EventRecord(kind=kind, occurred_at=datetime.now(UTC), key=key, attrs=attrs)
+
+
+async def rows(sink, *where):
+    t = sink.embeddings
+    if not await sink._has_table(t.name):  # created on the first embedding
+        return []
+    async with sink.engine.connect() as conn:
+        result = await conn.execute(select(t).where(*where).order_by(t.c.source_id))
+        return [dict(r) for r in result.mappings()]
+
+
+async def settle(mw, emb):
+    await mw.flush()
+    await emb.flush()
+
+
+class TestExtractTexts:
+    def test_call_errors(self):
+        ok = call_record(outcome="ok")
+        err = call_record(message="render timed out", error_type="TimeoutError")
+        soft = call_record(
+            tool="find",
+            outcome="soft_error",
+            message="status=unknown_target",
+            error_type="SoftError",
+        )
+        items = extract_texts([ok, err, soft])
+        assert [(i.source_type, i.source_id, i.text) for i in items] == [
+            ("call_error", err.id, "render: TimeoutError: render timed out"),
+            ("call_error", soft.id, "find: SoftError: status=unknown_target"),
+        ]
+
+    def test_feedback(self):
+        ev = event(
+            "feedback.submitted",
+            key="bug-7Q2X",
+            title="Render hangs",
+            description="the render tool hung on scene a",
+            type="bug",
+        )
+        [item] = extract_texts([ev])
+        assert (item.source_type, item.source_id, item.text) == (
+            "feedback",
+            "bug-7Q2X",
+            "Render hangs\nthe render tool hung on scene a",
+        )
+
+    def test_event_text_keys(self):
+        ev = event(
+            "job.failed",
+            key="job-1",
+            error_excerpt="solver diverged",
+            reason="residual NaN",
+            nproc=8,
+        )
+        quiet = event("job.finished", key="job-2", duration_s=3)
+        [item] = extract_texts([ev, quiet])
+        assert (item.source_type, item.source_id, item.text) == (
+            "event",
+            ev.id,
+            "solver diverged\nresidual NaN",
+        )
+        [custom] = extract_texts([quiet], event_text_keys=("duration_s",))
+        assert custom.text == "3"
+
+    def test_llm(self):
+        ev = event("llm.call", model="m", prompt="why red?", completion="the light")
+        [item] = extract_texts([ev])
+        assert (item.source_type, item.source_id, item.text) == (
+            "llm",
+            ev.id,
+            "prompt: why red?\ncompletion: the light",
+        )
+
+    def test_llm_without_text_is_a_plain_event(self):
+        ev = event("llm.call", model="m", ok=False, error="upstream 529 overloaded")
+        [item] = extract_texts([ev])
+        assert (item.source_type, item.text) == ("event", "upstream 529 overloaded")
+
+    def test_sources_filter(self):
+        records = [
+            call_record(),
+            event("feedback.submitted", key="1", title="t", description="d"),
+            event("job.failed", error="boom"),
+            event("llm.call", prompt="p"),
+        ]
+        assert {i.source_type for i in extract_texts(records)} == {
+            "call_error",
+            "feedback",
+            "event",
+            "llm",
+        }
+        assert [
+            i.source_type for i in extract_texts(records, sources=["feedback"])
+        ] == ["feedback"]
+
+
+class TestEmbeddingSink:
+    async def test_every_source_lands(self, db):
+        sink = db()
+        fake = FakeEmbedder()
+        emb = EmbeddingSink(fake, sink)
+        err = call_record()
+        records = [
+            err,
+            event(
+                "feedback.submitted",
+                key="42",
+                title="Render hangs",
+                description="scene a",
+            ),
+            event("job.failed", key="job-1", error_excerpt="solver diverged"),
+            event("llm.call", prompt="hello", completion="hi"),
+        ]
+        await emb.write(records)
+        await emb.flush()
+        stored = await rows(sink)
+        assert {r["source_type"] for r in stored} == {
+            "call_error",
+            "feedback",
+            "event",
+            "llm",
+        }
+        for r in stored:
+            assert r["dim"] == DIM and r["model"] == "fake-embed"
+            assert len(r["embedding"]) == DIM
+            assert r["text_hash"] == hashlib.sha256(r["text"].encode()).hexdigest()
+            assert r["created_at"] is not None
+        assert emb.embedded == 4 and emb.errors == 0
+        await emb.aclose()
+
+    async def test_submit_feedback_is_embedded(self, db, tmp_path):
+        app = FastMCP("app")
+        sink = db("fb")
+        fake = FakeEmbedder()
+        emb = EmbeddingSink(fake, sink)
+        mw = instrument(app, [sink, emb])
+        add_feedback_tools(
+            app, database_url=f"sqlite:///{tmp_path}/fb.db", instrumentation=mw
+        )
+        async with Client(app) as client:
+            result = await client.call_tool(
+                "submit_feedback",
+                {
+                    "request": {
+                        "type": "bug",
+                        "title": "Render hangs",
+                        "description": "the render tool hung on scene a",
+                        "submitter": "model",
+                    }
+                },
+            )
+        ref = result.data["feedback_id"]
+        await settle(mw, emb)
+        [row] = await rows(sink, sink.embeddings.c.source_type == "feedback")
+        assert row["source_id"] == ref
+        assert row["text"] == "Render hangs\nthe render tool hung on scene a"
+        [ev] = await mw.events_for(ref, kinds=["feedback.submitted"])
+        assert ev["attrs"]["type"] == "bug" and ev["attrs"]["submitter"] == "model"
+        await mw.aclose()
+
+    async def test_redaction(self, db):
+        sink = db()
+        fake = FakeEmbedder()
+        emb = EmbeddingSink(
+            fake, sink, redactor=Redactor(extra_patterns=[r"acme_\w{8}"])
+        )
+        # Straight to the sink, so upstream redaction cannot hide a gap here.
+        await emb.write(
+            [
+                call_record(message=f"401 with api_key={SECRET} and acme_12345678"),
+                event("job.failed", error=f"Bearer {SECRET}"),
+            ]
+        )
+        await emb.flush()
+        assert fake.seen and all(
+            SECRET not in t and "acme_12345678" not in t for t in fake.seen
+        )
+        stored = await rows(sink)
+        assert len(stored) == 2
+        for r in stored:
+            assert SECRET not in r["text"] and REDACTED in r["text"]
+        await emb.aclose()
+
+    async def test_instrument_hands_over_its_redactor(self, db):
+        app = FastMCP("app")
+        sink = db()
+        emb = EmbeddingSink(FakeEmbedder(), sink)
+        redactor = Redactor(extra_patterns=[r"acme_\w{8}"])
+        mw = instrument(app, [sink, emb], redactor=redactor)
+        assert emb.redactor is redactor
+        await mw.aclose()
+
+    async def test_max_chars(self, db):
+        sink = db()
+        fake = FakeEmbedder()
+        emb = EmbeddingSink(fake, sink, max_chars=50)
+        await emb.write([event("job.failed", error="word " * 100)])
+        await emb.flush()
+        [row] = await rows(sink)
+        assert len(row["text"]) == 50 and fake.seen == [row["text"]]
+        await emb.aclose()
+
+    async def test_dedupe_and_replace(self, db):
+        sink = db()
+        fake = FakeEmbedder()
+        emb = EmbeddingSink(fake, sink)
+        ev = event("feedback.submitted", key="7", title="Render hangs", description="a")
+        await emb.write([ev])
+        await emb.flush()
+        await emb.write([ev, ev])
+        await emb.flush()
+        assert fake.seen == ["Render hangs\na"]
+        assert emb.skipped == 2
+        changed = event(
+            "feedback.submitted", key="7", title="Render hangs", description="b"
+        )
+        await emb.write([changed])
+        await emb.flush()
+        [row] = await rows(sink)
+        assert row["text"] == "Render hangs\nb"
+        assert fake.seen == ["Render hangs\na", "Render hangs\nb"]
+        # Another model's vectors are kept apart.
+        other = EmbeddingSink(FakeEmbedder(model="other"), sink)
+        await other.write([changed])
+        await other.flush()
+        assert len(await rows(sink)) == 2
+        await emb.aclose()
+        await other.aclose()
+
+    async def test_queue_full_drops(self, db):
+        sink = db()
+        gate = asyncio.Event()
+        fake = FakeEmbedder(gate=gate)
+        emb = EmbeddingSink(fake, sink, max_queue=2, batch_size=1)
+        start = time.perf_counter()
+        await emb.write([event("job.failed", error=f"boom {i}") for i in range(6)])
+        assert time.perf_counter() - start < 0.5
+        await asyncio.sleep(0.05)  # the worker takes one and blocks on the gate
+        await emb.write([event("job.failed", error=f"late {i}") for i in range(3)])
+        assert emb.dropped >= 4
+        gate.set()
+        await emb.flush()
+        assert emb.errors == 0
+        assert len(await rows(sink)) == 9 - emb.dropped
+        await emb.aclose()
+
+    async def test_embedder_errors_never_reach_tool_calls(self, db):
+        app = FastMCP("app")
+
+        @app.tool
+        def render(scene: str) -> str:
+            raise RuntimeError(f"render of {scene} timed out")
+
+        @app.tool
+        def ping() -> str:
+            return "pong"
+
+        sink = db()
+        emb = EmbeddingSink(FakeEmbedder(fail=True), sink)
+        mw = instrument(app, [sink, emb])
+        async with Client(app) as client:
+            with contextlib.suppress(ToolError):
+                await client.call_tool("render", {"scene": "a"})
+            assert (await client.call_tool("ping", {})).data == "pong"
+        await settle(mw, emb)
+        assert emb.errors == 1
+        assert mw.dispatcher.sink_errors == 0
+        assert await rows(sink) == []
+        async with sink.engine.connect() as conn:
+            calls = (
+                await conn.execute(select(func.count()).select_from(sink.table))
+            ).scalar_one()
+        assert calls == 2
+        assert await mw.similar("render timed out") == []
+        await mw.aclose()
+
+    async def test_slow_embedder_stays_off_the_call_path(self, db):
+        app = FastMCP("app")
+
+        @app.tool
+        def render() -> str:
+            raise RuntimeError("render timed out")
+
+        sink = db()
+        emb = EmbeddingSink(FakeEmbedder(delay=2.0), sink, timeout=5.0)
+        mw = instrument(app, [sink, emb], sink_timeout=0.5)
+        async with Client(app) as client:
+            start = time.perf_counter()
+            for _ in range(3):
+                with contextlib.suppress(ToolError):
+                    await client.call_tool("render", {})
+            elapsed = time.perf_counter() - start
+        await mw.flush()
+        assert elapsed < 1.5
+        assert mw.dispatcher.sink_errors == 0
+        await emb.flush()
+        assert emb.embedded == 3
+        await mw.aclose()
+
+    async def test_wrong_vector_length_is_an_error(self, db):
+        sink = db()
+        emb = EmbeddingSink(FakeEmbedder(out_dim=DIM + 1), sink)
+        await emb.write([event("job.failed", error="boom")])
+        await emb.flush()
+        assert emb.errors == 1 and await rows(sink) == []
+        await emb.aclose()
+
+    async def test_dim_mismatch_refused_at_construction(self, db):
+        with pytest.raises(ValueError, match="embedding_dim=512"):
+            EmbeddingSink(FakeEmbedder(dim=512), db())
+
+    async def test_unknown_source_refused(self, db):
+        with pytest.raises(ValueError, match="unknown sources"):
+            EmbeddingSink(FakeEmbedder(), db(), sources=["feedback", "chat"])
+
+    async def test_aclose_drains(self, db):
+        sink = db()
+        emb = EmbeddingSink(FakeEmbedder(delay=0.1), sink, batch_size=1)
+        await emb.write([event("job.failed", error=f"e{i}") for i in range(3)])
+        await emb.aclose()
+        assert emb.embedded == 3 and emb.dropped == 0
+
+    async def test_aclose_timeout_drops(self, db):
+        sink = db()
+        emb = EmbeddingSink(
+            FakeEmbedder(gate=asyncio.Event()), sink, batch_size=1, timeout=0.2
+        )
+        await emb.write([event("job.failed", error=f"e{i}") for i in range(3)])
+        await emb.aclose()
+        assert emb.dropped == 2 and emb.embedded == 0
+
+
+class TestLlmText:
+    def app(self, sinks, **kwargs):
+        app = FastMCP("llm")
+        holder = {}
+
+        @app.tool
+        async def ask(q: str) -> str:
+            holder["mw"].record_llm_call(
+                model="m",
+                prompt=f"{q} token={SECRET}",
+                completion="because",
+                attrs={"prompt": "smuggled", "temperature": 0.2},
+            )
+            return "because"
+
+        holder["mw"] = mw = instrument(app, sinks, **kwargs)
+        return app, mw
+
+    async def test_dropped_by_default(self, db):
+        sink = db()
+        fake = FakeEmbedder()
+        emb = EmbeddingSink(fake, sink)
+        app, mw = self.app([sink, emb])
+        async with Client(app) as client:
+            await client.call_tool("ask", {"q": "why is the sky blue"})
+        await settle(mw, emb)
+        [ev] = [e for e in mw.recent_events if e.kind == "llm.call"]
+        assert "prompt" not in ev.attrs and "completion" not in ev.attrs
+        assert ev.attrs["temperature"] == 0.2
+        assert fake.seen == []
+        assert await rows(sink) == []
+        await mw.aclose()
+
+    async def test_embedded_when_captured(self, db):
+        sink = db()
+        fake = FakeEmbedder()
+        emb = EmbeddingSink(fake, sink)
+        app, mw = self.app([sink, emb], capture_llm_text=True, max_error_chars=10)
+        async with Client(app) as client:
+            await client.call_tool("ask", {"q": "why is the sky blue " * 10})
+        await settle(mw, emb)
+        [ev] = [e for e in mw.recent_events if e.kind == "llm.call"]
+        assert len(ev.attrs["prompt"]) == 80  # 8 * max_error_chars
+        assert ev.attrs["completion"] == "because"
+        [row] = await rows(sink)
+        assert row["source_type"] == "llm" and row["source_id"] == ev.id
+        assert row["text"].startswith("prompt: why is the sky blue")
+        assert row["text"].endswith("completion: because")
+        await mw.aclose()
+
+    async def test_captured_text_is_redacted(self, db):
+        sink = db()
+        emb = EmbeddingSink(FakeEmbedder(), sink)
+        app, mw = self.app([sink, emb], capture_llm_text=True)
+        async with Client(app) as client:
+            await client.call_tool("ask", {"q": "q"})
+        await settle(mw, emb)
+        [ev] = [e for e in mw.recent_events if e.kind == "llm.call"]
+        assert SECRET not in ev.attrs["prompt"] and REDACTED in ev.attrs["prompt"]
+        [row] = await rows(sink)
+        assert SECRET not in row["text"]
+        await mw.aclose()
+
+
+FIXTURE = [
+    ("call_error", "c1", "render: TimeoutError: render timed out after 30 s"),
+    ("call_error", "c2", "upload: OSError: disk full on volume data"),
+    ("event", "e1", "render job timed out waiting for the gpu"),
+    ("feedback", "bug-1", "Render hangs\nthe render tool timed out on scene a"),
+    ("feedback", "bug-2", "Dark mode please\nthe ui is too bright at night"),
+    ("llm", "l1", "prompt: summarise the log\ncompletion: nothing notable"),
+]
+
+
+async def seed(sink, emb):
+    from fastmcp_feedback.instrumentation import EmbeddingText
+
+    for source_type, source_id, text_ in FIXTURE:
+        emb._enqueue(EmbeddingText(source_type, source_id, text_))
+    await emb.flush()
+    assert len(await rows(sink)) == len(FIXTURE)
+
+
+class TestSimilar:
+    async def test_ranking_matches_brute_force(self, db, db_backend):
+        sink = db()
+        app = FastMCP("s")
+        emb = EmbeddingSink(FakeEmbedder(), sink)
+        mw = instrument(app, [sink, emb])
+        await seed(sink, emb)
+
+        query = "render timed out"
+        q = token_vector(query)
+        expected = sorted(
+            ((cosine_score(q, token_vector(t)), sid) for _, sid, t in FIXTURE),
+            reverse=True,
+        )
+        found = await mw.similar(query, k=len(FIXTURE))
+        # Rows sharing no word with the query all score 0; their order is free.
+        positive = [sid for score, sid in expected if score > 1e-6]
+        assert len(positive) >= 3
+        assert [r["source_id"] for r in found][: len(positive)] == positive
+        assert {r["source_id"] for r in found} == {sid for _, sid in expected}
+        want = {sid: score for score, sid in expected}
+        for r in found:
+            assert r["score"] == pytest.approx(want[r["source_id"]], abs=1e-4)
+            assert 0.0 <= r["score"] <= 1.0
+            assert r["created_at"].tzinfo is not None
+            assert set(r) == {"source_type", "source_id", "text", "score", "created_at"}
+        assert found[0]["source_id"] == "c1"
+
+        top = await mw.similar(query, k=2)
+        assert [r["source_id"] for r in top] == positive[:2]
+        only = await mw.similar(query, source_types=["feedback"])
+        assert [r["source_id"] for r in only] == ["bug-1", "bug-2"]
+        strong = await mw.similar(query, min_score=0.4)
+        assert strong and all(r["score"] >= 0.4 for r in strong)
+        assert len(strong) < len(FIXTURE)
+        await mw.aclose()
+
+    async def test_similar_feedback_excludes_itself(self, db):
+        sink = db()
+        app = FastMCP("s")
+        emb = EmbeddingSink(FakeEmbedder(), sink)
+        mw = instrument(app, [sink, emb])
+        await seed(sink, emb)
+        found = await mw.similar_feedback("bug-1", k=3)
+        assert "bug-1" not in [r["source_id"] for r in found]
+        assert found[0]["source_id"] in ("c1", "e1")
+        feedback_only = await mw.similar_feedback("bug-1", source_types=["feedback"])
+        assert [r["source_id"] for r in feedback_only] == ["bug-2"]
+        assert await mw.similar_feedback("bug-404") == []
+        await mw.aclose()
+
+    async def test_scan_limit_without_pgvector(self, db, db_backend, caplog):
+        if db_backend == "postgres":
+            pytest.skip("brute force only runs without pgvector")
+        sink = db()
+        app = FastMCP("s")
+        emb = EmbeddingSink(FakeEmbedder(), sink, scan_limit=2)
+        mw = instrument(app, [sink, emb])
+        await seed(sink, emb)
+        caplog.set_level(logging.INFO, "fastmcp_feedback.instrumentation.embeddings")
+        assert len(await mw.similar("render", k=10)) <= 2
+        await mw.similar("render", k=10)
+        assert len([r for r in caplog.records if "scan_limit" in r.getMessage()]) == 1
+        await mw.aclose()
+
+    async def test_never_raises(self, db):
+        app = FastMCP("s")
+        mw = instrument(app, [])
+        assert await mw.similar("x") == []
+        assert await mw.similar_feedback("1") == []
+        await mw.aclose()
+        sink = db()
+        emb = EmbeddingSink(FakeEmbedder(fail=True), sink)
+        mw = instrument(FastMCP("t"), [sink, emb])
+        assert await mw.similar("x") == []
+        # No table yet: the lookup itself fails.
+        assert await mw.similar_feedback("1") == []
+        await mw.aclose()
+
+
+class TestPrune:
+    async def test_keeps_feedback_embeddings(self, db):
+        sink = db(prune_batch=2)
+        emb = EmbeddingSink(FakeEmbedder(), sink)
+        await seed(sink, emb)
+        t = sink.embeddings
+        old = datetime.now(UTC) - timedelta(days=40)
+        async with sink.engine.begin() as conn:
+            await conn.execute(
+                update(t).where(t.c.source_id != "c2").values(created_at=old)
+            )
+        deleted = await sink.prune(older_than=datetime.now(UTC) - timedelta(days=30))
+        assert deleted == 3
+        left = sorted(r["source_id"] for r in await rows(sink))
+        assert left == ["bug-1", "bug-2", "c2"]
+        await emb.aclose()
+
+    async def test_prune_without_embeddings_table(self, db):
+        sink = db()
+        await sink.write([call_record()])
+        assert not await sink._has_table(sink.embeddings.name)
+        assert await sink.prune(older_than=datetime.now(UTC) + timedelta(days=1)) == 1
+
+
+class TestCreateTables:
+    async def test_embeddings_table_only_with_an_embedding_sink(self, db):
+        sink = db()
+        await sink.write([call_record()])
+        assert not await sink._has_table(sink.embeddings.name)
+        emb = EmbeddingSink(FakeEmbedder(), sink)
+        await emb.write([call_record()])
+        await emb.flush()
+        assert await sink._has_table(sink.embeddings.name)
+        await emb.aclose()
+
+    async def test_create_tables_false_creates_nothing(self, db):
+        sink = db(create_tables=False)
+        assert await sink.ensure_embeddings() is True
+        assert not await sink._has_table(sink.embeddings.name)
+
+    async def test_failure_is_logged_not_raised(self, db, monkeypatch, caplog):
+        sink = db()
+
+        async def boom():
+            raise RuntimeError("no room")
+
+        monkeypatch.setattr(sink, "_create_embeddings_table", boom)
+        caplog.set_level(logging.WARNING)
+        emb = EmbeddingSink(FakeEmbedder(), sink)
+        assert await sink.ensure_embeddings() is False
+        assert any("Could not create" in r.getMessage() for r in caplog.records)
+        await emb.write([call_record()])
+        await emb.flush()
+        assert emb.errors == 1  # the insert fails; counted, not raised
+        await emb.aclose()
+
+    @pytest.mark.postgres
+    async def test_postgres_extension_table_and_index(self, db, db_backend):
+        if db_backend != "postgres":
+            pytest.skip("Postgres only")
+        sink = db()
+        await sink._ready()
+        async with sink.engine.begin() as conn:
+            await conn.execute(text("DROP EXTENSION IF EXISTS vector"))
+        assert await sink.ensure_embeddings() is True
+        async with sink.engine.connect() as conn:
+            ext = (
+                await conn.execute(
+                    text("SELECT count(*) FROM pg_extension WHERE extname = 'vector'")
+                )
+            ).scalar_one()
+            index = (
+                await conn.execute(
+                    text(
+                        "SELECT indexdef FROM pg_indexes "
+                        "WHERE indexname = 'ffb_embeddings_hnsw'"
+                    )
+                )
+            ).scalar_one()
+            coltype = (
+                await conn.execute(
+                    text(
+                        "SELECT format_type(atttypid, atttypmod) FROM pg_attribute "
+                        "WHERE attrelid = 'ffb_embeddings'::regclass "
+                        "AND attname = 'embedding'"
+                    )
+                )
+            ).scalar_one()
+        assert ext == 1
+        assert "hnsw" in index and "vector_cosine_ops" in index
+        assert coltype == f"vector({DIM})"
+
+    @pytest.mark.postgres
+    async def test_postgres_without_privilege(self, db, db_backend, db_url, caplog):
+        if db_backend != "postgres":
+            pytest.skip("Postgres only")
+        from sqlalchemy.engine import make_url
+
+        admin = db("priv", embedding_dim=DIM)
+        role = f"ffb_limited_{uuid.uuid4().hex[:8]}"
+        password = uuid.uuid4().hex
+        url = make_url(db_url("priv"))
+        async with admin.engine.begin() as conn:
+            await conn.execute(text("DROP EXTENSION IF EXISTS vector"))
+            await conn.execute(text(f"CREATE ROLE {role} LOGIN PASSWORD '{password}'"))
+            await conn.execute(text(f"GRANT ALL ON SCHEMA public TO {role}"))
+        limited = DatabaseSink(
+            url.set(username=role, password=password).render_as_string(
+                hide_password=False
+            ),
+            create_tables=True,
+            embedding_dim=DIM,
+        )
+        try:
+            caplog.set_level(logging.WARNING)
+            emb = EmbeddingSink(FakeEmbedder(), limited)
+            assert await limited.ensure_embeddings() is False
+            messages = [r.getMessage() for r in caplog.records]
+            assert any("CREATE EXTENSION vector failed" in m for m in messages)
+            assert any("Could not create" in m for m in messages)
+            await limited.write([call_record()])  # the rest still works
+            await emb.write([call_record()])
+            await emb.flush()
+            assert emb.errors == 1
+            await emb.aclose()
+        finally:
+            await limited.engine.dispose()
+            async with admin.engine.begin() as conn:
+                await conn.execute(text(f"DROP OWNED BY {role}"))
+                await conn.execute(text(f"DROP ROLE {role}"))
+
+
+class TestMetadata:
+    def test_build_metadata_tables(self):
+        md = build_metadata("x_", embedding_dim=768)
+        t = md.tables["x_embeddings"]
+        assert t.c.embedding.type.dim == 768
+        assert {c.name for c in t.c} == {
+            "id",
+            "source_type",
+            "source_id",
+            "model",
+            "dim",
+            "text_hash",
+            "text",
+            "created_at",
+            "embedding",
+        }
+        without = build_metadata("y_", embedding_dim=None)
+        assert "y_embeddings" not in without.tables
+        assert "y_tool_calls" in without.tables
+
+
+class TestOpenAIEmbedder:
+    def transport(self, handler):
+        from fastmcp_feedback.instrumentation.embeddings import _http_module
+
+        return _http_module().MockTransport(handler)
+
+    async def test_request_batches_and_order(self):
+        seen = []
+
+        def handler(request):
+            body = json.loads(request.content)
+            seen.append((request.url.path, request.headers.get("authorization"), body))
+            data = [
+                {"index": i, "embedding": [float(len(t)), 0.0, 1.0]}
+                for i, t in enumerate(body["input"])
+            ]
+            from fastmcp_feedback.instrumentation.embeddings import _http_module
+
+            return _http_module().Response(200, json={"data": list(reversed(data))})
+
+        e = OpenAIEmbedder(
+            "https://gw.example/v1/",
+            api_key="k",
+            model="m",
+            dim=3,
+            batch_size=2,
+            transport=self.transport(handler),
+        )
+        out = await e.embed(["a", "bb", "ccc"])
+        assert out == [[1.0, 0.0, 1.0], [2.0, 0.0, 1.0], [3.0, 0.0, 1.0]]
+        assert [s[0] for s in seen] == ["/v1/embeddings", "/v1/embeddings"]
+        assert seen[0][1] == "Bearer k"
+        assert [s[2]["input"] for s in seen] == [["a", "bb"], ["ccc"]]
+        assert all(s[2]["model"] == "m" for s in seen)
+        assert await e.embed([]) == []
+
+    async def test_dim_mismatch_raises(self):
+        from fastmcp_feedback.instrumentation.embeddings import _http_module
+
+        def handler(request):
+            return _http_module().Response(
+                200, json={"data": [{"index": 0, "embedding": [0.1, 0.2]}]}
+            )
+
+        e = OpenAIEmbedder(
+            "https://gw.example/v1", dim=3, transport=self.transport(handler)
+        )
+        with pytest.raises(ValueError, match="2-dim vector, expected 3"):
+            await e.embed(["a"])
+
+    async def test_http_error_raises(self):
+        from fastmcp_feedback.instrumentation.embeddings import _http_module
+
+        e = OpenAIEmbedder(
+            "https://gw.example/v1",
+            dim=3,
+            transport=self.transport(
+                lambda r: _http_module().Response(403, json={"error": "nope"})
+            ),
+        )
+        with pytest.raises(Exception, match="403"):
+            await e.embed(["a"])
+
+
+LIVE_URL = os.environ.get("FFB_TEST_EMBED_URL")
+
+
+@pytest.mark.skipif(not LIVE_URL, reason="FFB_TEST_EMBED_URL is not set")
+async def test_live_gateway():
+    """FFB_TEST_EMBED_URL=https://.../v1 FFB_TEST_EMBED_KEY=... [FFB_TEST_EMBED_MODEL]."""
+    e = OpenAIEmbedder(
+        LIVE_URL,
+        api_key=os.environ.get("FFB_TEST_EMBED_KEY"),
+        model=os.environ.get("FFB_TEST_EMBED_MODEL", "mxbai-embed-large"),
+        dim=int(os.environ.get("FFB_TEST_EMBED_DIM", "1024")),
+    )
+    a, b, c = await e.embed(
+        ["render timed out", "the render took too long and timed out", "dark mode"]
+    )
+    assert len(a) == e.dim
+    assert cosine_score(a, b) > cosine_score(a, c)

tests/unit/test_events.py

@@ -0,0 +1,582 @@
+"""Tests for events: record_event, record_llm_call, events_for and their storage.
+
+Real FastMCP servers through fastmcp.Client, as in test_instrumentation.py.
+"""
+
+import asyncio
+import contextlib
+import io
+import json
+import threading
+from datetime import UTC, datetime, timedelta
+
+import pytest
+from fastmcp import Client, FastMCP
+from fastmcp.exceptions import ToolError
+from sqlalchemy import MetaData, func, select
+from sqlalchemy.exc import DBAPIError
+
+from fastmcp_feedback.instrumentation import (
+    REDACTED,
+    CallbackSink,
+    DatabaseSink,
+    EventRecord,
+    JsonLinesSink,
+    MemorySink,
+    ToolCallRecord,
+    build_metadata,
+    instrument,
+)
+
+
+@pytest.fixture
+async def db(db_url):
+    """DatabaseSinks whose engines are always disposed, or the process hangs."""
+    made = []
+
+    def factory(name="calls", **kwargs):
+        kwargs.setdefault("create_tables", True)
+        sink = DatabaseSink(db_url(name), **kwargs)
+        made.append(sink)
+        return sink
+
+    yield factory
+    for sink in made:
+        await sink.engine.dispose()
+
+
+def make_app(sinks=None, **kwargs):
+    """A server whose tools record events through the middleware returned."""
+    sink = MemorySink()
+    app = FastMCP("events")
+    holder = {}
+    spawned = []
+
+    @app.tool
+    async def submit(job_id: str) -> dict:
+        mw = holder["mw"]
+        mw.record_event("job.submitted", key=job_id, attrs={"case": "wing", "nproc": 4})
+        return {"job_id": job_id}
+
+    @app.tool
+    def submit_sync(job_id: str) -> dict:
+        holder["mw"].record_event("job.submitted", key=job_id)
+        return {"job_id": job_id}
+
+    @app.tool
+    async def spawn(job_id: str) -> dict:
+        """Start a watcher task that records after the call has returned."""
+        started = asyncio.Event()
+
+        async def watcher():
+            started.set()
+            await asyncio.sleep(0.05)
+            holder["mw"].record_event("job.started", key=job_id)
+
+        spawned.append(asyncio.get_running_loop().create_task(watcher()))
+        await started.wait()
+        return {"job_id": job_id}
+
+    @app.tool
+    async def chat(prompt: str) -> str:
+        holder["mw"].record_llm_call(
+            model="claude-opus-4",
+            provider="anthropic",
+            duration_ms=812.5,
+            input_tokens=1200,
+            output_tokens=90,
+            attrs={"cache_read_input_tokens": 1000},
+        )
+        return "ok"
+
+    @app.tool
+    async def chat_fails(prompt: str) -> str:
+        err = RuntimeError(
+            "upstream 401: api_key=sk-abcdefghijklmnopqrstuv " + "x" * 800
+        )
+        holder["mw"].record_llm_call(model="gpt-x", provider="openai", error=err)
+        raise err
+
+    @app.tool
+    def poll() -> dict:
+        return {"status": "idle"}
+
+    @app.tool
+    def poll_with_event() -> dict:
+        holder["mw"].record_event("poll.saw_job", key="j9")
+        return {"status": "idle"}
+
+    mw = instrument(app, sinks if sinks is not None else [sink], **kwargs)
+    holder["mw"] = mw
+    return app, sink, mw, spawned
+
+
+async def call(app, mw, *calls):
+    async with Client(app) as client:
+        for tool, args in calls:
+            with contextlib.suppress(ToolError):
+                await client.call_tool(tool, args)
+    await mw.flush()
+
+
+async def table_rows(sink, table):
+    async with sink.engine.connect() as conn:
+        return [dict(r) for r in (await conn.execute(select(table))).mappings()]
+
+
+def event(kind="job.step", key="j1", minutes_ago=0, **kwargs):
+    return EventRecord(
+        kind=kind,
+        occurred_at=datetime.now(UTC) - timedelta(minutes=minutes_ago),
+        key=key,
+        **kwargs,
+    )
+
+
+class TestLinking:
+    async def test_event_in_tool_links_to_stored_call(self, db):
+        store = db()
+        app, _, mw, _ = make_app([store])
+        await call(app, mw, ("submit", {"job_id": "j1"}))
+        [call_row] = await table_rows(store, store.table)
+        [ev] = await table_rows(store, store.events)
+        assert ev["kind"] == "job.submitted"
+        assert ev["call_id"] == call_row["id"]
+        assert ev["session_id"] == call_row["session_id"]
+        assert ev["call_id"] == mw.recent[-1].id
+
+    async def test_sync_tool_links_too(self):
+        app, sink, mw, _ = make_app()
+        await call(app, mw, ("submit_sync", {"job_id": "j2"}))
+        await asyncio.sleep(0.01)
+        await mw.flush()
+        [ev] = sink.events
+        [rec] = sink.calls
+        assert ev.call_id == rec.id
+
+    async def test_event_outside_call_has_no_call_id(self):
+        app, sink, mw, _ = make_app()
+        assert mw.record_event("job.finished", key="j1") is True
+        await mw.flush()
+        [ev] = sink.events
+        assert ev.call_id is None and ev.session_id is None
+
+    async def test_task_outliving_call_is_not_linked(self):
+        app, sink, mw, spawned = make_app()
+        await call(app, mw, ("spawn", {"job_id": "j3"}))
+        await asyncio.gather(*spawned)
+        await mw.flush()
+        [ev] = sink.events
+        assert ev.kind == "job.started" and ev.call_id is None
+
+    async def test_explicit_call_id_wins(self):
+        app, sink, mw, _ = make_app()
+        mw.record_event("x.y", call_id="given")
+        await mw.flush()
+        assert sink.events[0].call_id == "given"
+
+    async def test_sampled_out_call_kept_when_it_recorded_event(self):
+        app, sink, mw, _ = make_app(
+            sample_rates={"poll_with_event": 0.01, "poll": 0.01},
+            random=lambda: 0.99,
+        )
+        await call(app, mw, ("poll", {}), ("poll_with_event", {}))
+        [rec] = sink.calls
+        [ev] = sink.events
+        assert rec.tool == "poll_with_event" and rec.sample_rate is None
+        assert ev.call_id == rec.id
+
+    async def test_excluded_tool_events_unlinked(self):
+        app, sink, mw, _ = make_app(exclude_tools={"poll_with_event"})
+        await call(app, mw, ("poll_with_event", {}))
+        assert sink.calls == []
+        [ev] = sink.events
+        assert ev.call_id is None
+
+
+class TestRecordEvent:
+    async def test_key_attrs_and_server_version_stored(self, db):
+        store = db()
+        app, _, mw, _ = make_app([store], server_version="1.2.3")
+        mw.record_event(
+            "step.finished",
+            key=42,
+            attrs={"step": "snappyHexMesh", "cells": 1200000, "mesh_ok": True},
+            user_sub="u1",
+        )
+        await mw.flush()
+        [ev] = await table_rows(store, store.events)
+        assert ev["key"] == "42"
+        assert ev["attrs"] == {
+            "step": "snappyHexMesh",
+            "cells": 1200000,
+            "mesh_ok": True,
+        }
+        assert ev["user_sub"] == "u1" and ev["server_version"] == "1.2.3"
+
+    async def test_attrs_redacted(self):
+        app, sink, mw, _ = make_app()
+        mw.record_event(
+            "job.failed",
+            attrs={
+                "token": "abc123",
+                "nested": {"db_password": "hunter2"},
+                "error_excerpt": "curl -H 'Authorization: Bearer abcdefghijklmnop'",
+            },
+        )
+        await mw.flush()
+        attrs = sink.events[0].attrs
+        assert attrs["token"] == REDACTED
+        assert attrs["nested"]["db_password"] == REDACTED
+        assert "abcdefghijklmnop" not in attrs["error_excerpt"]
+
+    async def test_attrs_made_json_safe(self, db):
+        store = db()
+        app, _, mw, _ = make_app([store])
+        when = datetime(2026, 9, 29, tzinfo=UTC)
+        mw.record_event(
+            "solver.progress",
+            key="j1",
+            attrs={"residuals": {"p": float("nan"), "U": 1e-5}, "at": when, 3: (1, 2)},
+        )
+        await mw.flush()
+        [ev] = await table_rows(store, store.events)
+        assert ev["attrs"] == {
+            "residuals": {"p": "nan", "U": 1e-5},
+            "at": when.isoformat(),
+            "3": [1, 2],
+        }
+
+    @pytest.mark.parametrize(
+        "kind",
+        ["", "   ", None, 5, "k" * 129],
+        ids=["empty", "blank", "none", "int", "long"],
+    )
+    async def test_invalid_kind_rejected(self, kind):
+        app, sink, mw, _ = make_app()
+        assert mw.record_event(kind) is False
+        await mw.flush()
+        assert sink.events == [] and list(mw.recent_events) == []
+
+    async def test_invalid_key_and_attrs_rejected(self):
+        app, sink, mw, _ = make_app()
+        assert mw.record_event("a.b", key="k" * 256) is False
+        assert mw.record_event("a.b", attrs=["not", "a", "dict"]) is False
+        await mw.flush()
+        assert sink.events == []
+
+    async def test_mode_off_is_noop(self):
+        app, sink, mw, _ = make_app(mode="off")
+        assert mw.record_event("job.submitted", key="j1") is False
+        assert mw.record_llm_call(model="m") is False
+        await call(app, mw, ("submit", {"job_id": "j1"}))
+        assert sink.records == [] and list(mw.recent_events) == []
+        assert mw.dispatcher.dropped == 0
+
+    async def test_queue_full_returns_false_and_counts(self):
+        app, sink, mw, _ = make_app(max_queue=1)
+        assert mw.record_event("a.one") is True
+        assert mw.record_event("a.two") is False
+        assert mw.dispatcher.dropped == 1
+        await mw.flush()
+        assert [e.kind for e in sink.events] == ["a.one"]
+        assert [e.kind for e in mw.recent_events] == ["a.one"]
+
+    async def test_broken_sink_never_raises(self):
+        def boom(records):
+            raise RuntimeError("sink down")
+
+        app, _, mw, _ = make_app([CallbackSink(boom)])
+        assert mw.record_event("a.b", key="j") is True
+        await mw.flush()
+        assert mw.dispatcher.sink_errors == 1
+
+    async def test_broken_redactor_never_raises(self):
+        app, sink, mw, _ = make_app()
+
+        class Broken:
+            def redact(self, value):
+                raise RuntimeError("bad pattern")
+
+        mw.redactor = Broken()
+        assert mw.record_event("a.b", attrs={"x": 1}) is False
+
+
+class TestThreads:
+    async def test_record_from_thread_while_server_runs(self, db):
+        store = db()
+        app, _, mw, _ = make_app([store])
+        results = []
+        async with Client(app) as client:
+            await client.call_tool("submit", {"job_id": "j1"})
+
+            def watcher():
+                for kind in ("step.started", "job.finished"):
+                    results.append(
+                        mw.record_event(kind, key="j1", attrs={"case": "wing"})
+                    )
+
+            t = threading.Thread(target=watcher)
+            t.start()
+            await asyncio.to_thread(t.join)
+            await asyncio.sleep(0)
+        await mw.flush()
+        assert results == [True, True]
+        rows = await table_rows(store, store.events)
+        assert sorted(r["kind"] for r in rows) == [
+            "job.finished",
+            "job.submitted",
+            "step.started",
+        ]
+        threaded = [r for r in rows if r["kind"] != "job.submitted"]
+        assert all(r["call_id"] is None for r in threaded)
+        assert [e.kind for e in mw.recent_events] == [
+            "job.submitted",
+            "step.started",
+            "job.finished",
+        ]
+
+    async def test_thread_with_its_own_loop_hands_over(self):
+        app, sink, mw, _ = make_app()
+        mw.record_event("a.first")  # binds the dispatcher to this loop
+        out = []
+        t = threading.Thread(
+            target=lambda: out.append(asyncio.run(self._record_in_loop(mw)))
+        )
+        t.start()
+        await asyncio.to_thread(t.join)
+        await asyncio.sleep(0)
+        await mw.flush()
+        assert out == [True]
+        assert [e.kind for e in sink.events] == ["a.first", "a.second"]
+        assert mw.dispatcher._loop is asyncio.get_running_loop()
+
+    @staticmethod
+    async def _record_in_loop(mw):
+        return mw.record_event("a.second")
+
+    def test_no_loop_and_nothing_recorded_drops(self):
+        app, sink, mw, _ = make_app()
+        assert mw.record_event("job.started", key="j1") is False
+        assert mw.dispatcher.dropped == 1
+        assert list(mw.recent_events) == []
+
+    async def test_thread_before_anything_recorded_drops(self):
+        app, sink, mw, _ = make_app()
+        out = []
+        t = threading.Thread(target=lambda: out.append(mw.record_event("a.b")))
+        t.start()
+        await asyncio.to_thread(t.join)
+        assert out == [False] and mw.dispatcher.dropped == 1
+
+
+class TestLlmCall:
+    async def test_attrs_and_linking(self, db):
+        store = db()
+        app, _, mw, _ = make_app([store])
+        await call(app, mw, ("chat", {"prompt": "hi"}))
+        [call_row] = await table_rows(store, store.table)
+        [ev] = await table_rows(store, store.events)
+        assert ev["kind"] == "llm.call" and ev["call_id"] == call_row["id"]
+        assert ev["attrs"] == {
+            "cache_read_input_tokens": 1000,
+            "model": "claude-opus-4",
+            "provider": "anthropic",
+            "duration_ms": 812.5,
+            "input_tokens": 1200,
+            "output_tokens": 90,
+            "ok": True,
+        }
+
+    async def test_error_redacted_truncated_and_not_ok(self):
+        app, sink, mw, _ = make_app(max_error_chars=100)
+        await call(app, mw, ("chat_fails", {"prompt": "hi"}))
+        [ev] = sink.events
+        attrs = ev.attrs
+        assert attrs["ok"] is False and attrs["error_type"] == "RuntimeError"
+        assert "sk-abcdefghijklmnopqrstuv" not in attrs["error"]
+        assert len(attrs["error"]) == 100
+        assert ev.call_id == sink.calls[0].id and sink.calls[0].outcome == "error"
+
+    async def test_named_fields_win_and_ok_explicit(self):
+        app, sink, mw, _ = make_app()
+        mw.record_llm_call(
+            model="m", ok=False, key="turn-1", attrs={"model": "spoofed", "round": 2}
+        )
+        await mw.flush()
+        [ev] = sink.events
+        assert ev.key == "turn-1"
+        assert ev.attrs == {"model": "m", "round": 2, "ok": False}
+
+
+class TestSinks:
+    async def test_database_sink_mixed_batch(self, db):
+        store = db()
+        rec = ToolCallRecord(
+            tool="t",
+            started_at=datetime.now(UTC),
+            duration_ms=1.0,
+            ok=True,
+            mode="meta",
+        )
+        ev = event(call_id=rec.id, attrs={"a": 1})
+        await store.write([rec, ev])
+        assert [r["id"] for r in await table_rows(store, store.table)] == [rec.id]
+        [row] = await table_rows(store, store.events)
+        assert row["id"] == ev.id and row["call_id"] == rec.id
+
+    async def test_hand_built_event_attrs_made_json_safe(self, db):
+        store = db()
+        await store.write([event(attrs={"p": float("nan"), "q": float("-inf")})])
+        [row] = await table_rows(store, store.events)
+        assert row["attrs"] == {"p": "nan", "q": "-inf"}
+
+    async def test_database_sink_events_only_and_calls_only(self, db):
+        store = db()
+        await store.write([event()])
+        assert len(await table_rows(store, store.events)) == 1
+        assert await table_rows(store, store.table) == []
+
+    async def test_calls_stored_when_events_table_missing(self, db):
+        store = db("old", create_tables=False)
+        old = MetaData()
+        build_metadata("ffb_", old)
+        old.remove(old.tables["ffb_events"])
+        async with store.engine.begin() as conn:
+            await conn.run_sync(old.create_all)
+        rec = ToolCallRecord(
+            tool="t",
+            started_at=datetime.now(UTC),
+            duration_ms=1.0,
+            ok=True,
+            mode="meta",
+        )
+        # SQLite raises OperationalError, Postgres ProgrammingError.
+        with pytest.raises(DBAPIError, match="no such table|does not exist"):
+            await store.write([rec, event()])
+        assert len(await table_rows(store, store.table)) == 1
+
+    async def test_json_lines_record_field(self):
+        stream = io.StringIO()
+        app, _, mw, _ = make_app([JsonLinesSink(stream)])
+        await call(app, mw, ("submit", {"job_id": "j1"}))
+        lines = [json.loads(line) for line in stream.getvalue().splitlines()]
+        by_type = {line["record"]: line for line in lines}
+        assert set(by_type) == {"tool_call", "event"}
+        assert by_type["event"]["kind"] == "job.submitted"
+        assert by_type["event"]["call_id"] == by_type["tool_call"]["id"]
+        assert by_type["tool_call"]["tool"] == "submit"
+
+    async def test_memory_sink_calls_and_events(self):
+        app, sink, mw, _ = make_app()
+        await call(app, mw, ("submit", {"job_id": "j1"}), ("poll", {}))
+        assert [r.tool for r in sink.calls] == ["submit", "poll"]
+        assert [e.kind for e in sink.events] == ["job.submitted"]
+        assert len(sink.records) == 3
+
+
+class TestEventsFor:
+    async def test_merges_database_and_memory_in_time_order(self, db):
+        store = db()
+        app, _, mw, _ = make_app([store])
+        # Written by another worker: only in the database.
+        await store.write([event("job.submitted", minutes_ago=30)])
+        # Recorded here and flushed: in both, returned once.
+        mw.record_event("step.started", key="j1")
+        await mw.flush()
+        # Recorded here, not yet written: only in memory.
+        pending = event("step.finished", minutes_ago=-1)
+        mw.recent_events.append(pending)
+        # Another job, and a kind filtered out below.
+        mw.record_event("job.submitted", key="j2")
+        await mw.flush()
+
+        rows = await mw.events_for("j1")
+        assert [r["kind"] for r in rows] == [
+            "job.submitted",
+            "step.started",
+            "step.finished",
+        ]
+        assert all(r["occurred_at"].tzinfo is not None for r in rows)
+        assert rows[-1]["id"] == pending.id
+        assert len({r["id"] for r in rows}) == 3
+
+        steps = await mw.events_for("j1", kinds=["step.started", "step.finished"])
+        assert [r["kind"] for r in steps] == ["step.started", "step.finished"]
+        last = await mw.events_for("j1", limit=2)
+        assert [r["kind"] for r in last] == ["step.started", "step.finished"]
+
+    async def test_memory_only_without_database(self):
+        app, sink, mw, _ = make_app()
+        await call(app, mw, ("submit", {"job_id": "j1"}))
+        mw.record_event("job.finished", key="j1")
+        rows = await mw.events_for("j1")
+        assert [r["kind"] for r in rows] == ["job.submitted", "job.finished"]
+        assert rows[0]["call_id"] == sink.calls[0].id
+
+    async def test_database_failure_falls_back_to_memory(self, db):
+        store = db("nodb", create_tables=False)
+        app, _, mw, _ = make_app([store])
+        mw.recent_events.append(event("job.submitted"))
+        rows = await mw.events_for("j1")
+        assert [r["kind"] for r in rows] == ["job.submitted"]
+
+
+class TestPrune:
+    async def test_prune_deletes_old_events_in_batches(self, db):
+        store = db(retention=timedelta(days=30), prune_batch=2)
+        old_call = ToolCallRecord(
+            tool="old",
+            started_at=datetime.now(UTC) - timedelta(days=40),
+            duration_ms=1.0,
+            ok=True,
+            mode="meta",
+        )
+        store._last_prune = float("inf")  # keep write() from pruning first
+        await store.write(
+            [old_call]
+            + [event(f"old.{i}", minutes_ago=60 * 24 * 40) for i in range(5)]
+            + [event("new.one"), event("new.two", minutes_ago=60 * 24 * 29)]
+        )
+        statements = []
+        from sqlalchemy import event as sa_event
+
+        def count_deletes(conn, cursor, statement, *args):
+            if statement.lstrip().upper().startswith("DELETE FROM FFB_EVENTS"):
+                statements.append(statement)
+
+        sa_event.listen(
+            store.engine.sync_engine, "before_cursor_execute", count_deletes
+        )
+        deleted = await store.prune()
+        assert deleted == 6  # 1 call + 5 events
+        assert len(statements) == 3  # 2 + 2 + 1
+        kinds = sorted(r["kind"] for r in await table_rows(store, store.events))
+        assert kinds == ["new.one", "new.two"]
+
+    async def test_auto_prune_covers_events(self, db):
+        store = db(retention=timedelta(days=30))
+        await store.write([event("old", minutes_ago=60 * 24 * 31), event("new")])
+        assert [r["kind"] for r in await table_rows(store, store.events)] == ["new"]
+
+    async def test_prune_without_events_table(self, db):
+        store = db("legacy", create_tables=False)
+        old = MetaData()
+        build_metadata("ffb_", old)
+        old.remove(old.tables["ffb_events"])
+        async with store.engine.begin() as conn:
+            await conn.run_sync(old.create_all)
+        rec = ToolCallRecord(
+            tool="old",
+            started_at=datetime.now(UTC) - timedelta(days=40),
+            duration_ms=1.0,
+            ok=True,
+            mode="meta",
+        )
+        await store.write([rec])
+        assert await store.prune(datetime.now(UTC) - timedelta(days=30)) == 1
+        async with store.engine.connect() as conn:
+            n = (
+                await conn.execute(select(func.count()).select_from(store.table))
+            ).scalar()
+        assert n == 0

tests/unit/test_feedback_servers.py

@@ -345,7 +345,7 @@ class TestServerComposition:
     async def test_compose_feedback_services_success(self):
         """Test successful service composition."""
         main_server = Mock()
-        main_server.import_server = Mock()
+        main_server.mount = Mock()
 
         services = {
             "service1": {
@@ -376,13 +376,38 @@ class TestServerComposition:
             mock_submission.assert_called_once()
             mock_management.assert_called_once()
             mock_feedback.assert_called_once()
-            assert main_server.import_server.call_count == 3
+            assert main_server.mount.call_count == 3
+
+    @pytest.mark.asyncio
+    async def test_compose_feedback_services_real_servers(self, tmp_path):
+        """Composed tools must actually appear under their prefix.
+
+        The mocked tests above can't catch a missing await: a sync Mock
+        records the call either way. This one uses real FastMCP servers.
+        """
+        from fastmcp import FastMCP
+
+        from tests._compat import tool_map
+
+        main_server = FastMCP("Main")
+        compose_feedback_services(
+            main_server,
+            {
+                "public": {"database_url": f"sqlite:///{tmp_path}/p.db", "type": "submission"},
+                "admin": {"database_url": f"sqlite:///{tmp_path}/a.db", "type": "full"},
+            },
+        )
+
+        names = set(await tool_map(main_server))
+        assert "public_submit_feedback" in names
+        assert "admin_list_feedback" in names
+        assert "admin_update_feedback_status" in names
 
     @pytest.mark.asyncio
     async def test_compose_feedback_services_with_shared_insights(self):
         """Test service composition with shared insights."""
         main_server = Mock()
-        main_server.import_server = Mock()
+        main_server.mount = Mock()
         shared_insights = Mock()
 
         services = {

tests/unit/test_instrumentation.py

@@ -0,0 +1,492 @@
+"""Tests for per-call instrumentation: redaction, middleware, dispatch, sinks.
+
+These run against real FastMCP servers through fastmcp.Client, so they
+exercise the same middleware path on every supported FastMCP version.
+"""
+
+import asyncio
+import io
+import json
+import time
+
+import pytest
+from fastmcp import Client, FastMCP
+from fastmcp.exceptions import ToolError
+from sqlalchemy import MetaData, inspect, select
+from sqlalchemy.ext.asyncio import create_async_engine
+
+from fastmcp_feedback import add_feedback_tools
+from fastmcp_feedback.instrumentation import (
+    REDACTED,
+    CallbackSink,
+    DatabaseSink,
+    InstrumentationMiddleware,
+    JsonLinesSink,
+    MemorySink,
+    RecordDispatcher,
+    Redactor,
+    ToolCallRecord,
+    build_metadata,
+    instrument,
+)
+
+BMCP_TOKEN = "bmcp_" + "A1b2C3d4E5f6G7h8I9j0"
+JWT = "eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOiIxMjM0NTYifQ.c2lnbmF0dXJlLXZhbHVl"
+
+
+def make_app(sinks=None, **kwargs):
+    sink = MemorySink()
+    app = FastMCP("instrumented")
+
+    @app.tool
+    def echo(text: str) -> dict:
+        return {"echo": text}
+
+    @app.tool
+    def create_token(label: str) -> dict:
+        return {"label": label, "access_token": BMCP_TOKEN, "note": f"use {BMCP_TOKEN}"}
+
+    @app.tool
+    def login(user: str, password: str) -> str:
+        return f"welcome {user}"
+
+    @app.tool
+    def fail(secret: str) -> str:
+        raise ValueError(f"bad input secret={secret}")
+
+    mw = instrument(app, sinks if sinks is not None else [sink], **kwargs)
+    return app, sink, mw
+
+
+async def call(app, tool, args=None):
+    async with Client(app) as client:
+        return await client.call_tool(tool, args or {})
+
+
+class TestRedactor:
+    def test_secret_keys_at_any_depth(self):
+        data = {"a": {"b": [{"password": "hunter2", "keep": 1}]}, "Authorization": "x"}
+        out = Redactor().redact(data)
+        assert out["a"]["b"][0] == {"password": REDACTED, "keep": 1}
+        assert out["Authorization"] == REDACTED
+
+    def test_suffix_and_dash_variants(self):
+        out = Redactor().redact(
+            {
+                "github_token": "t",
+                "DB-Password": "p",
+                "X-Api-Key": "k",
+                "stripe_api_key": "s",
+            }
+        )
+        assert set(out.values()) == {REDACTED}
+
+    def test_non_secret_keys_untouched(self):
+        data = {"max_tokens": 100, "token_count": 3, "tool": "echo", "tokens": [1, 2]}
+        assert Redactor().redact(data) == data
+
+    def test_secret_values_inside_text(self):
+        text = f"pat {BMCP_TOKEN}, jwt {JWT}, header Bearer abcdefghijklmnop, key sk-{'x' * 20}"
+        out = Redactor().redact_text(text)
+        for secret in (BMCP_TOKEN, JWT, "abcdefghijklmnop", "sk-"):
+            assert secret not in out
+        assert out.count(REDACTED) == 4
+
+    def test_key_value_text_keeps_the_key(self):
+        out = Redactor().redact_text("failed: password=hunter2 api_key: abc123, ok")
+        assert out == f"failed: password={REDACTED} api_key: {REDACTED}, ok"
+
+    def test_input_not_mutated(self):
+        data = {"password": "hunter2", "nested": {"token": "t"}}
+        Redactor().redact(data)
+        assert data == {"password": "hunter2", "nested": {"token": "t"}}
+
+    def test_none_secret_value_left_as_none(self):
+        assert Redactor().redact({"password": None}) == {"password": None}
+
+    def test_extra_keys_and_patterns(self):
+        r = Redactor(extra_keys=["license"], extra_patterns=[r"ACME-\d{6}"])
+        assert r.redact({"license": "L", "msg": "code ACME-123456"}) == {
+            "license": REDACTED,
+            "msg": f"code {REDACTED}",
+        }
+
+    def test_depth_limit(self):
+        deep = current = {}
+        for _ in range(50):
+            current["n"] = {}
+            current = current["n"]
+        assert "[TRUNCATED]" in json.dumps(Redactor(max_depth=5).redact(deep))
+
+
+class TestMiddlewareRecording:
+    async def test_success_in_meta_mode(self):
+        app, sink, mw = make_app()
+        await call(app, "echo", {"text": "hello"})
+        await mw.flush()
+
+        [rec] = sink.records
+        assert rec.tool == "echo" and rec.ok and rec.mode == "meta"
+        assert rec.duration_ms > 0
+        assert rec.args_size == len(json.dumps({"text": "hello"}))
+        assert rec.result_size and rec.result_size > 0
+        assert rec.args is None and rec.result is None
+        assert rec.session_id and rec.request_id
+
+    async def test_full_mode_redacts_args_and_results(self):
+        app, sink, mw = make_app(mode="full")
+        await call(app, "create_token", {"label": "ci"})
+        await call(app, "login", {"user": "ryan", "password": "hunter2"})
+        await mw.flush()
+
+        token_rec, login_rec = sink.records
+        dumped = json.dumps([token_rec.to_dict(), login_rec.to_dict()])
+        assert BMCP_TOKEN not in dumped and "hunter2" not in dumped
+        assert token_rec.result["access_token"] == REDACTED
+        assert token_rec.result["note"] == f"use {REDACTED}"
+        assert token_rec.result["label"] == "ci"
+        assert login_rec.args == {"user": "ryan", "password": REDACTED}
+
+    async def test_failed_call_recorded_and_error_unchanged(self):
+        app, sink, mw = make_app()
+        with pytest.raises(ToolError, match="bad input"):
+            await call(app, "fail", {"secret": "hunter2"})
+        await mw.flush()
+
+        [rec] = sink.records
+        assert not rec.ok
+        assert rec.error_type == "ValueError"
+        assert "hunter2" not in rec.error_message
+        assert f"secret={REDACTED}" in rec.error_message
+
+    async def test_meta_only_tools_override_full_mode(self):
+        app, sink, mw = make_app(mode="full", meta_only_tools={"create_token"})
+        await call(app, "create_token", {"label": "ci"})
+        await call(app, "echo", {"text": "hi"})
+        await mw.flush()
+
+        token_rec, echo_rec = sink.records
+        assert token_rec.mode == "meta" and token_rec.result is None
+        assert token_rec.result_size > 0
+        assert echo_rec.mode == "full" and echo_rec.result == {"echo": "hi"}
+
+    async def test_off_mode_records_nothing(self):
+        app, sink, mw = make_app(mode="off")
+        await call(app, "echo", {"text": "hi"})
+        await mw.flush()
+        assert sink.records == []
+
+    async def test_mode_from_environment(self, monkeypatch):
+        monkeypatch.setenv("FEEDBACK_INSTRUMENTATION_MODE", "full")
+        assert InstrumentationMiddleware([]).mode == "full"
+
+    def test_invalid_mode_rejected(self):
+        with pytest.raises(ValueError, match="mode must be one of"):
+            InstrumentationMiddleware([], mode="everything")
+
+
+class TestHooks:
+    async def test_identity_resolver_fills_columns(self):
+        def who(context):
+            assert context.fastmcp_context is not None
+            return {
+                "user_sub": "user-1",
+                "caller_kind": "pat:7",
+                "client_id": "blender-addon",
+                "org": "acme",
+                "token": BMCP_TOKEN,
+            }
+
+        app, sink, mw = make_app(identity_resolver=who)
+        await call(app, "echo", {"text": "hi"})
+        await mw.flush()
+
+        [rec] = sink.records
+        assert (rec.user_sub, rec.caller_kind, rec.client_id) == (
+            "user-1",
+            "pat:7",
+            "blender-addon",
+        )
+        assert rec.identity == {"org": "acme", "token": REDACTED}
+
+    async def test_async_enricher_gets_result_and_sets_extra(self):
+        seen = {}
+
+        async def enrich(tool, args, result, context):
+            seen.update(tool=tool, args=args, result=result)
+            return {"job_id": "job-42", "server_version": "2026.9.27", "api_key": "k"}
+
+        app, sink, mw = make_app(enricher=enrich, server_version="default")
+        await call(app, "echo", {"text": "hi"})
+        await mw.flush()
+
+        [rec] = sink.records
+        assert seen == {
+            "tool": "echo",
+            "args": {"text": "hi"},
+            "result": {"echo": "hi"},
+        }
+        assert rec.extra == {"job_id": "job-42", "api_key": REDACTED}
+        assert rec.server_version == "2026.9.27"
+
+    async def test_server_version_default(self):
+        app, sink, mw = make_app(server_version="1.0")
+        await call(app, "echo", {"text": "hi"})
+        await mw.flush()
+        assert sink.records[0].server_version == "1.0"
+
+    async def test_hook_exceptions_do_not_break_calls(self):
+        def boom(*args):
+            raise RuntimeError("hook bug")
+
+        app, sink, mw = make_app(identity_resolver=boom, enricher=boom)
+        result = await call(app, "echo", {"text": "hi"})
+        await mw.flush()
+
+        assert result.data == {"echo": "hi"}
+        [rec] = sink.records
+        assert rec.ok and rec.identity == {} and rec.extra == {}
+
+    async def test_slow_async_hook_is_cut_off(self):
+        async def slow(*args):
+            await asyncio.sleep(5)
+            return {"never": True}
+
+        app, sink, mw = make_app(enricher=slow, hook_timeout=0.05)
+        start = time.perf_counter()
+        await call(app, "echo", {"text": "hi"})
+        assert time.perf_counter() - start < 2
+        await mw.flush()
+        assert sink.records[0].extra == {}
+
+
+class TestNeverBlocksOrBreaks:
+    async def test_failing_sink_does_not_break_calls_or_other_sinks(self):
+        class Broken:
+            async def write(self, records):
+                raise ConnectionError("database down")
+
+        good = MemorySink()
+        app, _, mw = make_app(sinks=[Broken(), good])
+        result = await call(app, "echo", {"text": "hi"})
+        await mw.flush()
+
+        assert result.data == {"echo": "hi"}
+        assert mw.dispatcher.sink_errors == 1
+        assert len(good.records) == 1
+
+    async def test_stalled_sink_drops_records_instead_of_waiting(self):
+        release = asyncio.Event()
+
+        class Stalled:
+            def __init__(self):
+                self.records = []
+
+            async def write(self, records):
+                await release.wait()
+                self.records.extend(records)
+
+        stalled = Stalled()
+        app, _, mw = make_app(sinks=[stalled], max_queue=2, batch_size=1)
+
+        start = time.perf_counter()
+        async with Client(app) as client:
+            for i in range(6):
+                await client.call_tool("echo", {"text": str(i)})
+        assert time.perf_counter() - start < 3
+
+        # One record is in the stalled write, two fit the queue, the rest drop.
+        assert mw.dispatcher.dropped == 3
+        release.set()
+        await mw.flush()
+        assert len(stalled.records) == 3
+
+    async def test_record_building_failure_does_not_break_calls(self, monkeypatch):
+        app, sink, mw = make_app()
+
+        async def explode(*args, **kwargs):
+            raise RuntimeError("bug in record building")
+
+        monkeypatch.setattr(mw, "_build_record", explode)
+        result = await call(app, "echo", {"text": "hi"})
+        assert result.data == {"echo": "hi"}
+
+    async def test_tool_error_passes_through_even_if_recording_fails(self, monkeypatch):
+        app, sink, mw = make_app()
+
+        async def explode(*args, **kwargs):
+            raise RuntimeError("bug in record building")
+
+        monkeypatch.setattr(mw, "_build_record", explode)
+        with pytest.raises(ToolError, match="bad input"):
+            await call(app, "fail", {"secret": "x"})
+
+    def test_submit_without_event_loop_drops(self):
+        dispatcher = RecordDispatcher([MemorySink()])
+        record = ToolCallRecord(
+            tool="t",
+            started_at=__import__("datetime").datetime.now(),
+            duration_ms=1,
+            ok=True,
+            mode="meta",
+        )
+        assert dispatcher.submit(record) is False
+        assert dispatcher.dropped == 1
+
+
+class TestSinks:
+    async def test_json_lines_sink(self):
+        stream = io.StringIO()
+        app, _, mw = make_app(sinks=[JsonLinesSink(stream)])
+        await call(app, "echo", {"text": "hi"})
+        await call(app, "echo", {"text": "again"})
+        await mw.flush()
+
+        lines = [json.loads(line) for line in stream.getvalue().splitlines()]
+        assert [line["tool"] for line in lines] == ["echo", "echo"]
+        assert lines[0]["started_at"].endswith("+00:00")
+
+    async def test_callback_sink_sync_and_async(self):
+        got_sync, got_async = [], []
+
+        async def async_cb(records):
+            got_async.extend(records)
+
+        app, _, mw = make_app(
+            sinks=[CallbackSink(got_sync.extend), CallbackSink(async_cb)]
+        )
+        await call(app, "echo", {"text": "hi"})
+        await mw.flush()
+        assert len(got_sync) == len(got_async) == 1
+
+    async def test_aclose_closes_sinks(self):
+        closed = []
+
+        class Closable(MemorySink):
+            async def aclose(self):
+                closed.append(True)
+
+        app, _, mw = make_app(sinks=[Closable()])
+        await call(app, "echo", {"text": "hi"})
+        await mw.aclose()
+        assert closed == [True]
+
+
+class TestDatabaseSink:
+    async def test_end_to_end_with_created_tables(self, db_url):
+        db = DatabaseSink(db_url(), create_tables=True)
+        app, _, mw = make_app(sinks=[db], mode="full", server_version="9.9")
+        await call(app, "create_token", {"label": "ci"})
+        with pytest.raises(ToolError):
+            await call(app, "fail", {"secret": "hunter2"})
+        await mw.flush()
+
+        async with db.engine.connect() as conn:
+            rows = (
+                (await conn.execute(select(db.table).order_by(db.table.c.started_at)))
+                .mappings()
+                .all()
+            )
+        await mw.aclose()
+
+        assert [r["tool"] for r in rows] == ["create_token", "fail"]
+        assert rows[0]["ok"] is True and rows[1]["ok"] is False
+        assert rows[0]["result"]["access_token"] == REDACTED
+        assert rows[1]["error_type"] == "ValueError"
+        assert rows[0]["server_version"] == "9.9"
+        assert "hunter2" not in json.dumps([dict(r) for r in rows], default=str)
+
+    async def test_prefix_and_host_owned_engine(self, db_url):
+        engine = create_async_engine(db_url("host"))
+        db = DatabaseSink(engine, prefix="qa_", create_tables=True)
+        app, _, mw = make_app(sinks=[db])
+        await call(app, "echo", {"text": "hi"})
+        await mw.aclose()
+
+        # The host's engine is still usable: the sink did not dispose it.
+        async with engine.connect() as conn:
+            tables = await conn.run_sync(lambda c: inspect(c).get_table_names())
+        await engine.dispose()
+        assert sorted(tables) == [
+            "qa_events",
+            "qa_feedback_call_links",
+            "qa_tool_calls",
+        ]
+
+    async def test_no_tables_created_by_default(self, db_url):
+        engine = create_async_engine(db_url("host"))
+        app, _, mw = make_app(sinks=[DatabaseSink(engine)])
+        result = await call(app, "echo", {"text": "hi"})
+        await mw.flush()
+
+        async with engine.connect() as conn:
+            tables = await conn.run_sync(lambda c: inspect(c).get_table_names())
+        await engine.dispose()
+
+        # The insert fails (no table), is counted, and the call still worked.
+        assert result.data == {"echo": "hi"}
+        assert tables == []
+        assert mw.dispatcher.sink_errors == 1
+
+    async def test_absent_payloads_are_sql_null(self, db_url):
+        """Meta mode stores no payloads; they must be SQL NULL, not JSON null."""
+        db = DatabaseSink(db_url("n"), create_tables=True)
+        app, _, mw = make_app(sinks=[db])
+        await call(app, "echo", {"text": "hi"})
+        await mw.flush()
+
+        t = db.table
+        async with db.engine.connect() as conn:
+            nulls = (
+                await conn.execute(select(t.c.args.is_(None), t.c.result.is_(None)))
+            ).one()
+        await mw.aclose()
+        assert tuple(nulls) == (True, True)
+
+    def test_build_metadata_joins_host_metadata(self):
+        host = MetaData()
+        assert build_metadata("ffb_", host) is host
+        build_metadata("ffb_", host)
+        assert sorted(host.tables) == [
+            "ffb_embeddings",
+            "ffb_events",
+            "ffb_feedback_call_links",
+            "ffb_tool_calls",
+        ]
+
+
+class TestIntegration:
+    async def test_records_mounted_server_tools_by_prefixed_name(self):
+        main = FastMCP("main")
+        sub = FastMCP("sub")
+
+        @sub.tool
+        def ping() -> str:
+            return "pong"
+
+        main.mount(sub, "svc")
+        sink = MemorySink()
+        mw = instrument(main, [sink])
+        await call(main, "svc_ping")
+        await mw.flush()
+        assert [r.tool for r in sink.records] == ["svc_ping"]
+
+    async def test_records_feedback_tools(self):
+        app = FastMCP("with-feedback")
+        add_feedback_tools(app, database_url="sqlite:///:memory:")
+        sink = MemorySink()
+        mw = instrument(app, [sink])
+        await call(
+            app,
+            "submit_feedback",
+            {
+                "request": {
+                    "type": "bug",
+                    "title": "t",
+                    "description": "instrumented",
+                    "submitter": "me",
+                }
+            },
+        )
+        await mw.flush()
+        assert [r.tool for r in sink.records] == ["submit_feedback"]

tests/unit/test_late_identity.py

@@ -0,0 +1,320 @@
+"""The identity resolver's second run, after the tool, for identity the tool creates.
+
+Modelled on blender-mcp: an addon calls register_client, and only after that
+call can the resolver find the bus client (bus_client_uuid, bus_role) for the
+caller's session. The first run, before the tool, already knows the user.
+"""
+
+import asyncio
+import contextlib
+import time
+
+from fastmcp import Client, FastMCP
+from fastmcp.exceptions import ToolError
+
+from fastmcp_feedback.instrumentation import REDACTED, MemorySink, instrument
+
+
+class Bus:
+    """Who is registered, as the tool leaves it; read by the resolvers."""
+
+    def __init__(self):
+        self.client = None
+
+
+class BlenderResolver:
+    """blender-mcp's identify(): user and role always, bus keys once registered."""
+
+    def __init__(self, bus):
+        self.bus = bus
+        self.calls = 0
+
+    def __call__(self, context):
+        self.calls += 1
+        out = {"user_sub": "user-1", "caller_kind": "addon", "client_id": "dcr-9"}
+        if self.bus.client is not None:
+            out["bus_client_uuid"] = self.bus.client
+            out["bus_role"] = "interactive"
+        return out
+
+
+class EmptyUntilRegistered:
+    """Nothing before registration, every field after."""
+
+    def __init__(self, bus):
+        self.bus = bus
+        self.calls = 0
+
+    def __call__(self, context):
+        self.calls += 1
+        if self.bus.client is None:
+            return {}
+        return {
+            "user_sub": "user-1",
+            "caller_kind": "addon",
+            "client_id": "dcr-9",
+            "bus_client_uuid": self.bus.client,
+        }
+
+
+def make_app(resolver_cls, *, late=(), sample=None, **kwargs):
+    bus = Bus()
+    resolver = resolver_cls(bus)
+    sink = MemorySink()
+    app = FastMCP("late-identity")
+    holder = {}
+
+    @app.tool
+    async def register_client(client_uuid: str) -> dict:
+        holder["mw"].record_event("bus.registering", key=client_uuid)
+        bus.client = client_uuid
+        return {"status": "ok"}
+
+    @app.tool
+    async def register_then_fail(client_uuid: str) -> dict:
+        bus.client = client_uuid
+        raise RuntimeError("registered, then broke")
+
+    @app.tool
+    async def quiet() -> str:
+        return "ok"
+
+    @app.tool
+    async def ping() -> str:
+        holder["mw"].record_event("bus.ping")
+        return "pong"
+
+    kwargs.setdefault("identity_resolver", resolver)
+    if sample is not None:
+        kwargs.update(
+            sample_rates={"ping": sample, "quiet": sample}, random=lambda: 0.99
+        )
+    mw = instrument(app, [sink], late_identity_keys=late, **kwargs)
+    holder["mw"] = mw
+    return app, sink, mw, resolver
+
+
+async def call(app, mw, *calls):
+    async with Client(app) as client:
+        for tool, args in calls:
+            with contextlib.suppress(ToolError):
+                await client.call_tool(tool, args)
+    await mw.flush()
+
+
+def columns(record):
+    return (record.user_sub, record.caller_kind, record.client_id)
+
+
+class TestRegistration:
+    async def test_blender_shaped_registration_row_gets_bus_identity(self):
+        app, sink, mw, who = make_app(BlenderResolver, late=("bus_client_uuid",))
+        await call(app, mw, ("register_client", {"client_uuid": "c-1"}))
+        [rec] = sink.calls
+        assert columns(rec) == ("user-1", "addon", "dcr-9")
+        assert rec.identity == {"bus_client_uuid": "c-1", "bus_role": "interactive"}
+        assert who.calls == 2
+        # The event recorded during the call saw the first answer only.
+        [ev] = sink.events
+        assert ev.call_id == rec.id and columns(ev) == ("user-1", "addon", "dcr-9")
+
+    async def test_blender_shaped_without_late_keys_runs_once(self):
+        # The first answer is not empty, so without late_identity_keys there
+        # is no second run and the row lacks the bus keys. Opt-in by design.
+        app, sink, mw, who = make_app(BlenderResolver)
+        await call(app, mw, ("register_client", {"client_uuid": "c-1"}))
+        [rec] = sink.calls
+        assert rec.identity == {} and "bus_client_uuid" not in rec.identity
+        assert columns(rec) == ("user-1", "addon", "dcr-9")
+        assert who.calls == 1
+
+    async def test_registered_caller_runs_once(self):
+        app, sink, mw, who = make_app(BlenderResolver, late=("bus_client_uuid",))
+        await call(
+            app,
+            mw,
+            ("register_client", {"client_uuid": "c-1"}),
+            ("ping", {}),
+            ("ping", {}),
+        )
+        assert who.calls == 2 + 1 + 1
+        assert [r.identity.get("bus_client_uuid") for r in sink.calls] == [
+            "c-1",
+            "c-1",
+            "c-1",
+        ]
+
+    async def test_empty_first_answer_filled_after(self):
+        app, sink, mw, who = make_app(EmptyUntilRegistered)
+        await call(app, mw, ("register_client", {"client_uuid": "c-2"}))
+        [rec] = sink.calls
+        [ev] = sink.events
+        assert columns(rec) == ("user-1", "addon", "dcr-9")
+        assert rec.identity == {"bus_client_uuid": "c-2"}
+        assert columns(ev) == (None, None, None)  # not rewritten
+        assert who.calls == 2
+
+    async def test_tool_that_raises_gets_second_run_too(self):
+        app, sink, mw, who = make_app(EmptyUntilRegistered)
+        await call(app, mw, ("register_then_fail", {"client_uuid": "c-3"}))
+        [rec] = sink.calls
+        assert rec.outcome == "error"
+        assert columns(rec) == ("user-1", "addon", "dcr-9")
+        assert who.calls == 2
+
+
+class TestMerge:
+    async def test_first_answer_wins_on_conflict(self):
+        answers = iter(
+            [
+                {"user_sub": "early", "caller_kind": None, "org": None},
+                {
+                    "user_sub": "late",
+                    "caller_kind": "k",
+                    "client_id": "c",
+                    "org": "acme",
+                    "team": "qa",
+                },
+            ]
+        )
+        app, sink, mw, _ = make_app(
+            EmptyUntilRegistered,
+            identity_resolver=lambda c: next(answers),
+            late=("team",),
+        )
+        await call(app, mw, ("ping", {}))
+        [rec] = sink.calls
+        [ev] = sink.events
+        assert columns(rec) == ("early", "k", "c")
+        assert rec.identity == {"org": "acme", "team": "qa"}
+        assert columns(ev) == ("early", None, None)
+
+    async def test_second_answer_redacted(self):
+        token = "bmcp_abcdefgh12345678"
+        answers = iter([{}, {"user_sub": "u", "caller_kind": f"pat:{token}"}])
+        app, sink, mw, _ = make_app(
+            EmptyUntilRegistered, identity_resolver=lambda c: next(answers)
+        )
+        await call(app, mw, ("ping", {}))
+        assert sink.calls[0].caller_kind == f"pat:{REDACTED}"
+
+
+class TestFailures:
+    async def test_second_run_raising_keeps_first_answer(self):
+        runs = []
+
+        def who(context):
+            runs.append(1)
+            if len(runs) == 1:
+                return {"user_sub": "u1"}
+            raise RuntimeError("resolver bug")
+
+        app, sink, mw, _ = make_app(
+            EmptyUntilRegistered, identity_resolver=who, late=("bus_client_uuid",)
+        )
+        await call(app, mw, ("ping", {}))
+        [rec] = sink.calls
+        assert rec.ok and rec.user_sub == "u1" and len(runs) == 2
+
+    async def test_second_run_timing_out_keeps_first_answer(self):
+        runs = []
+
+        async def who(context):
+            runs.append(1)
+            if len(runs) == 1:
+                return {"user_sub": "u1"}
+            await asyncio.sleep(5)
+            return {"user_sub": "late", "caller_kind": "k"}
+
+        app, sink, mw, _ = make_app(
+            EmptyUntilRegistered,
+            identity_resolver=who,
+            hook_timeout=0.05,
+            late=("bus_client_uuid",),
+        )
+        await call(app, mw, ("ping", {}))
+        [rec] = sink.calls
+        assert rec.ok and rec.user_sub == "u1" and rec.caller_kind is None
+        assert len(runs) == 2
+
+
+class McspeakResolver:
+    """mcspeak's _who: user_sub and caller_kind, never client_id."""
+
+    def __init__(self, bus):
+        self.calls = 0
+
+    def __call__(self, context):
+        self.calls += 1
+        return {"caller_kind": "claude-code", "user_sub": "mctalkbox"}
+
+
+class TestWhenItRuns:
+    async def test_missing_column_alone_does_not_rerun(self):
+        app, sink, mw, who = make_app(McspeakResolver)
+        await call(app, mw, ("ping", {}), ("quiet", {}), ("ping", {}))
+        assert who.calls == 3 and len(sink.calls) == 3
+        assert {columns(r) for r in sink.calls} == {("mctalkbox", "claude-code", None)}
+
+    async def test_only_none_values_count_as_empty(self):
+        answers = iter([{"user_sub": None}, {"user_sub": "u2", "caller_kind": "k"}])
+        app, sink, mw, _ = make_app(
+            EmptyUntilRegistered, identity_resolver=lambda c: next(answers)
+        )
+        await call(app, mw, ("ping", {}))
+        assert columns(sink.calls[0])[:2] == ("u2", "k")
+
+    async def test_complete_answer_runs_once(self):
+        app, sink, mw, who = make_app(BlenderResolver)
+        await call(app, mw, ("ping", {}), ("ping", {}))
+        assert who.calls == 2 and len(sink.calls) == 2
+
+    async def test_sampled_out_call_makes_no_second_run(self):
+        app, sink, mw, who = make_app(EmptyUntilRegistered, sample=0.1)
+        await call(app, mw, ("quiet", {}))
+        assert sink.calls == [] and who.calls == 1
+
+    async def test_sampled_call_kept_for_its_event_gets_second_run(self):
+        app, sink, mw, who = make_app(EmptyUntilRegistered, sample=0.1)
+        await call(app, mw, ("ping", {}))
+        assert len(sink.calls) == 1 and who.calls == 2
+
+    async def test_no_resolver_no_runs(self):
+        app, sink, mw, _ = make_app(EmptyUntilRegistered, identity_resolver=None)
+        await call(app, mw, ("ping", {}))
+        [rec] = sink.calls
+        assert columns(rec) == (None, None, None)
+
+    async def test_second_run_overlaps_enricher(self):
+        # The record is built before the result reaches the client, so the
+        # second run must not add its time to the enricher's.
+        runs = []
+
+        async def who(context):
+            runs.append(1)
+            if len(runs) > 1:
+                await asyncio.sleep(0.4)
+            return {}
+
+        async def enrich(tool, args, result, context):
+            await asyncio.sleep(0.4)
+            return {}
+
+        app, sink, mw, _ = make_app(
+            EmptyUntilRegistered,
+            identity_resolver=who,
+            enricher=enrich,
+            hook_timeout=2,
+        )
+        async with Client(app) as client:
+            start = time.perf_counter()
+            await client.call_tool("ping", {})
+            elapsed = time.perf_counter() - start
+        assert len(runs) == 2
+        assert elapsed < 0.75, elapsed
+
+
+async def test_mode_off_runs_nothing():
+    app, sink, mw, who = make_app(EmptyUntilRegistered, mode="off")
+    await call(app, mw, ("ping", {}))
+    assert who.calls == 0

tests/unit/test_mixins.py

@@ -7,6 +7,7 @@ from fastmcp import FastMCP
 from fastmcp_feedback.mixins import SubmissionMixin, RetrievalMixin, ManagementMixin
 from fastmcp_feedback.models import SubmitFeedbackRequest, FeedbackStatus
 from fastmcp_feedback.database import FeedbackDatabase
+from tests._compat import tool_map
 
 
 @pytest.mark.unit
@@ -95,7 +96,7 @@ class TestSubmissionMixin:
         mixin.register_tools(mock_fastmcp_server)
         
         # Verify tool was registered
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         assert "submit_feedback" in tool_names
     
@@ -107,7 +108,7 @@ class TestSubmissionMixin:
         mixin.register_tools(mock_fastmcp_server, prefix="support", separator="_")
         
         # Verify tool was registered with prefix
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         assert "support_submit_feedback" in tool_names
     
@@ -267,7 +268,7 @@ class TestRetrievalMixin:
         
         mixin.register_tools(mock_fastmcp_server)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         expected_tools = ["list_feedback", "get_feedback_statistics"]
@@ -437,7 +438,7 @@ class TestManagementMixin:
         
         mixin.register_tools(mock_fastmcp_server)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         expected_tools = ["update_feedback_status", "delete_feedback"]
@@ -508,7 +509,7 @@ class TestMixinIntegration:
         # 5. Get statistics
         stats = await retrieval.get_feedback_statistics()
         assert stats["total_count"] >= 1
-        assert "IN_PROGRESS" in stats["by_status"]
+        assert "in_progress" in stats["by_status"]
         
         # 6. Final status update
         final_result = await management.update_feedback_status(
@@ -532,7 +533,7 @@ class TestMixinIntegration:
         management.register_tools(mock_fastmcp_server)
         
         # Verify all tools are registered
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         expected_tools = [
@@ -555,7 +556,7 @@ class TestMixinIntegration:
         submission.register_tools(mock_fastmcp_server, prefix="admin")
         retrieval.register_tools(mock_fastmcp_server, prefix="public")
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         assert "admin_submit_feedback" in tool_names
@@ -663,7 +664,7 @@ class TestMixinConfiguration:
         # Register with dash separator
         submission.register_tools(mock_fastmcp_server, prefix="api", separator="-")
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         assert "api-submit_feedback" in tool_names
@@ -676,7 +677,7 @@ class TestMixinConfiguration:
         # Test the standard registration instead
         submission.register_tools(mock_fastmcp_server)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         # SubmissionMixin should only register its tools

tests/unit/test_payload_cap.py

@@ -0,0 +1,250 @@
+"""max_payload_bytes: stored arguments, results and event attrs are bounded."""
+
+import json
+
+import pytest
+from fastmcp import Client, FastMCP
+
+from fastmcp_feedback.instrumentation import (
+    REDACTED,
+    DatabaseSink,
+    EventRecord,
+    MemorySink,
+    instrument,
+)
+from fastmcp_feedback.instrumentation import payload as payload_mod
+from fastmcp_feedback.instrumentation.embeddings import extract_texts
+from fastmcp_feedback.instrumentation.payload import (
+    DEFAULT_MAX_PAYLOAD_BYTES,
+    PREVIEW_CHARS,
+    TRUNCATED,
+    cap_attrs,
+    is_truncated,
+    json_size,
+    preview_chars,
+)
+
+SECRET = "sk-" + "a1b2c3d4e5" * 4  # matches the default sk- pattern
+
+
+def make_app(**kwargs):
+    sink = MemorySink()
+    app = FastMCP("cap")
+    holder = {}
+
+    @app.tool
+    def echo(blob: str) -> dict:
+        return {"blob": blob}
+
+    @app.tool
+    def big(n: int) -> dict:
+        return {"rows": ["x" * 100] * n}
+
+    @app.tool
+    def report(error: str) -> str:
+        holder["mw"].record_event(
+            "job.finished", key="j1", attrs={"ok": False, "error": error}
+        )
+        return "ok"
+
+    kwargs.setdefault("mode", "full")
+    mw = instrument(app, [sink], **kwargs)
+    holder["mw"] = mw
+    return app, sink, mw
+
+
+async def call(app, mw, tool, args):
+    async with Client(app) as client:
+        await client.call_tool(tool, args)
+    await mw.flush()
+
+
+class TestCallPayloads:
+    async def test_default_is_64_kib(self):
+        app, sink, mw = make_app()
+        assert mw.max_payload_bytes == DEFAULT_MAX_PAYLOAD_BYTES == 65536
+
+    async def test_under_the_cap_stored_whole(self):
+        app, sink, mw = make_app()
+        await call(app, mw, "echo", {"blob": "y" * 1000})
+        [rec] = sink.calls
+        assert rec.args == {"blob": "y" * 1000}
+        assert rec.result == {"blob": "y" * 1000}
+
+    async def test_over_the_cap_becomes_a_marker(self):
+        app, sink, mw = make_app()
+        await call(app, mw, "big", {"n": 2000})
+        [rec] = sink.calls
+        assert rec.args == {"n": 2000}
+        assert rec.result_size > 65536
+        assert set(rec.result) == {TRUNCATED, "size", "preview"}
+        assert rec.result[TRUNCATED] is True
+        assert rec.result["size"] == rec.result_size
+        assert len(rec.result["preview"]) == PREVIEW_CHARS
+        assert rec.result["preview"].startswith('{"rows": ["xxxx')
+        json.dumps(rec.result)  # JSON-safe
+
+    async def test_args_over_the_cap(self):
+        app, sink, mw = make_app(max_payload_bytes=500)
+        await call(app, mw, "echo", {"blob": "z" * 2000})
+        [rec] = sink.calls
+        assert rec.args["size"] == rec.args_size and is_truncated(rec.args)
+        # Under a small cap the preview shrinks so the marker fits.
+        assert len(rec.args["preview"]) == preview_chars(500) == 125
+        assert json_size(rec.args) <= 500
+
+    async def test_none_means_unlimited(self):
+        app, sink, mw = make_app(max_payload_bytes=None)
+        await call(app, mw, "big", {"n": 20000})
+        [rec] = sink.calls
+        assert len(rec.result["rows"]) == 20000
+
+    async def test_meta_mode_stores_no_payload_but_sizes(self):
+        app, sink, mw = make_app(mode="meta")
+        await call(app, mw, "big", {"n": 2000})
+        [rec] = sink.calls
+        assert rec.args is None and rec.result is None
+        assert rec.result_size > 65536
+
+    @pytest.mark.parametrize("before_end", [40, 15])
+    async def test_redaction_happens_before_the_cap(self, before_end):
+        # At 15 the preview ends inside the secret: cutting the raw JSON there
+        # would leave a fragment too short for the pattern to match.
+        app, sink, mw = make_app(max_payload_bytes=4000)
+        pad = preview_chars(4000) - len('{"blob": "') - before_end
+        blob = "p" * pad + " " + SECRET + " " + "q" * 5000
+        await call(app, mw, "echo", {"blob": blob})
+        [rec] = sink.calls
+        for stored in (rec.args, rec.result):
+            assert is_truncated(stored)
+            assert SECRET[:8] not in stored["preview"]
+            assert "[REDACT" in stored["preview"]
+
+    async def test_secret_key_redacted_in_preview(self):
+        app, sink, mw = make_app(max_payload_bytes=200)
+        app.tool(lambda api_key, pad: "ok", name="login")
+        await call(app, mw, "login", {"api_key": "hunter2-secret", "pad": "x" * 500})
+        [rec] = sink.calls
+        assert "hunter2" not in rec.args["preview"]
+        assert REDACTED in rec.args["preview"]
+
+    @pytest.mark.parametrize("bad", [0, -1, True, "64k", 1.5])
+    def test_invalid_cap_rejected(self, bad):
+        with pytest.raises(ValueError, match="max_payload_bytes"):
+            make_app(max_payload_bytes=bad)
+
+
+class TestNoSecondEncoding:
+    async def test_payloads_encoded_once(self, monkeypatch):
+        # The size columns and the cap share one measurement per payload,
+        # whether or not the payload is over the cap.
+        app, sink, mw = make_app(max_payload_bytes=1000)
+        measured = []
+        original = payload_mod.json_size
+
+        def counting(value):
+            measured.append(1)
+            return original(value)
+
+        monkeypatch.setattr(
+            "fastmcp_feedback.instrumentation.middleware.json_size", counting
+        )
+        await call(app, mw, "echo", {"blob": "small"})
+        await call(app, mw, "big", {"n": 5000})
+        assert len(measured) == 4  # args and result, two calls
+        assert is_truncated(sink.calls[1].result)
+
+    def test_preview_stops_early(self, monkeypatch):
+        chunks = []
+        encoder = payload_mod._ENCODER
+
+        class Counting:
+            def iterencode(self, value):
+                for chunk in encoder.iterencode(value):
+                    chunks.append(chunk)
+                    yield chunk
+
+        monkeypatch.setattr(payload_mod, "_ENCODER", Counting())
+        huge = {"rows": ["x" * 100] * 100_000}  # about 10 MB
+        text = payload_mod.preview(huge)
+        assert len(text) == PREVIEW_CHARS
+        assert len(chunks) < 50
+
+
+class TestEventAttrs:
+    async def test_large_attr_replaced_small_ones_kept(self):
+        app, sink, mw = make_app(mode="meta")
+        await call(app, mw, "report", {"error": "E" * 100_000})
+        [ev] = sink.events
+        assert ev.attrs["ok"] is False
+        assert is_truncated(ev.attrs["error"])
+        assert ev.attrs["error"]["size"] == json_size("E" * 100_000)
+        assert json_size(ev.attrs) <= 65536
+
+    async def test_small_attrs_untouched(self):
+        app, sink, mw = make_app(mode="meta")
+        await call(app, mw, "report", {"error": "short"})
+        assert sink.events[0].attrs == {"ok": False, "error": "short"}
+
+    async def test_attrs_redacted_before_the_cap(self):
+        app, sink, mw = make_app(mode="meta", max_payload_bytes=4000)
+        error = "x" * (preview_chars(4000) - 30) + f" token {SECRET} " + "y" * 9000
+        await call(app, mw, "report", {"error": error})
+        stored = sink.events[0].attrs["error"]
+        assert SECRET[:8] not in stored["preview"] and REDACTED in stored["preview"]
+
+    async def test_outside_a_call_and_unlimited(self):
+        app, sink, mw = make_app(mode="meta", max_payload_bytes=None)
+        assert mw.record_event("job.log", key="j", attrs={"log": "L" * 200_000})
+        await mw.flush()
+        assert sink.events[0].attrs["log"] == "L" * 200_000
+
+    async def test_llm_call_attrs_capped_text_bounded(self):
+        app, sink, mw = make_app(mode="meta", capture_llm_text=True)
+        assert mw.record_llm_call(
+            model="m",
+            prompt="P" * 100_000,
+            attrs={"messages": ["M" * 1000] * 100},
+        )
+        await mw.flush()
+        [ev] = sink.events
+        assert len(ev.attrs["prompt"]) == mw.max_llm_text_chars
+        assert is_truncated(ev.attrs["messages"])
+        assert ev.attrs["model"] == "m" and ev.attrs["ok"] is True
+
+    def test_many_small_values_become_one_marker(self):
+        attrs = {f"k{i}": "v" * 50 for i in range(500)}
+        capped = cap_attrs(attrs, 1000)
+        assert is_truncated(capped) and capped["size"] == json_size(attrs)
+
+    def test_tiny_cap(self):
+        capped = cap_attrs({"a": "x" * 100}, 10)
+        assert is_truncated(capped) and len(capped["preview"]) == 2
+
+
+class TestDownstream:
+    async def test_marker_round_trips_through_database(self, db_url):
+        sink = DatabaseSink(db_url("cap"), create_tables=True)
+        try:
+            app, _, mw = make_app(mode="meta")
+            mw.dispatcher.sinks.append(sink)
+            await call(app, mw, "report", {"error": "E" * 100_000})
+            rows = await mw.events_for("j1")
+            [row] = [r for r in rows if r["kind"] == "job.finished"]
+            assert row["attrs"]["error"][TRUNCATED] is True
+            assert row["attrs"]["ok"] is False
+        finally:
+            await sink.engine.dispose()
+
+    def test_embedding_text_uses_the_preview(self):
+        from datetime import UTC, datetime
+
+        marker = payload_mod.marker("disk full: " + "z" * 5000, 5013, 100)
+        record = EventRecord(
+            kind="job.failed",
+            occurred_at=datetime.now(UTC),
+            attrs={"error": marker},
+        )
+        [text] = extract_texts([record])
+        assert text.text.startswith('"disk full: zzz')
+        assert "_truncated" not in text.text

tests/unit/test_retention_sampling.py

@@ -0,0 +1,403 @@
+"""Tests for per-tool exclusion, sampling and retention pruning.
+
+Real FastMCP servers through fastmcp.Client, as in test_instrumentation.py.
+"""
+
+import logging
+import time
+from datetime import UTC, datetime, timedelta
+
+import pytest
+from fastmcp import Client, FastMCP
+from fastmcp.exceptions import ToolError
+from sqlalchemy import event, func, select
+
+from fastmcp_feedback.instrumentation import (
+    DatabaseSink,
+    MemorySink,
+    ToolCallRecord,
+    instrument,
+)
+
+
+@pytest.fixture
+async def db(db_url):
+    """DatabaseSinks whose engines are always disposed, or the process hangs."""
+    made = []
+
+    def factory(name="calls", **kwargs):
+        sink = DatabaseSink(db_url(name), create_tables=True, **kwargs)
+        made.append(sink)
+        return sink
+
+    yield factory
+    for sink in made:
+        await sink.engine.dispose()
+
+
+class Rolls:
+    """Stand-in for random.random that returns the given values in turn."""
+
+    def __init__(self, *values):
+        self.values = list(values)
+        self.calls = 0
+
+    def __call__(self):
+        self.calls += 1
+        return self.values.pop(0)
+
+
+def make_app(sinks=None, **kwargs):
+    sink = MemorySink()
+    app = FastMCP("sampling")
+
+    @app.tool
+    def poll() -> dict:
+        return {"status": "idle"}
+
+    @app.tool
+    def render(status: str) -> dict:
+        return {"status": status, "detail": f"render said {status}"}
+
+    @app.tool
+    def crash() -> dict:
+        raise RuntimeError("exploded")
+
+    @app.tool
+    def other() -> str:
+        return "fine"
+
+    mw = instrument(app, sinks if sinks is not None else [sink], **kwargs)
+    return app, sink, mw
+
+
+async def call(app, mw, *calls):
+    """Run (tool, args) pairs; return the results, None where the tool raised."""
+    results = []
+    async with Client(app) as client:
+        for tool, args in calls:
+            try:
+                results.append(await client.call_tool(tool, args))
+            except ToolError:
+                results.append(None)
+    await mw.flush()
+    return results
+
+
+def old_record(tool="old", days=40, **kwargs):
+    return ToolCallRecord(
+        tool=tool,
+        started_at=datetime.now(UTC) - timedelta(days=days),
+        duration_ms=1.0,
+        ok=True,
+        mode="meta",
+        **kwargs,
+    )
+
+
+async def rows(sink, *columns):
+    t = sink.table
+    cols = [t.c[c] for c in columns] if columns else [t.c.tool]
+    async with sink.engine.connect() as conn:
+        return [
+            tuple(r)
+            for r in (await conn.execute(select(*cols).order_by(t.c.started_at))).all()
+        ]
+
+
+async def count(sink):
+    async with sink.engine.connect() as conn:
+        return (
+            await conn.execute(select(func.count()).select_from(sink.table))
+        ).scalar()
+
+
+class TestExclusion:
+    async def test_excluded_tool_not_recorded_nor_kept(self):
+        app, sink, mw = make_app(exclude_tools={"poll"})
+        results = await call(app, mw, ("poll", {}), ("other", {}), ("poll", {}))
+        assert [r.tool for r in sink.records] == ["other"]
+        assert [r.tool for r in mw.recent] == ["other"]
+        # The call itself is untouched.
+        assert results[0].structured_content == {"status": "idle"}
+
+    async def test_excluded_tool_failures_not_recorded_either(self):
+        app, sink, mw = make_app(exclude_tools=["crash"])
+        [result] = await call(app, mw, ("crash", {}))
+        assert result is None  # the error still reached the client
+        assert sink.records == []
+        assert list(mw.recent) == []
+
+    async def test_excluded_tool_skips_hooks(self):
+        seen = []
+        app, sink, mw = make_app(
+            exclude_tools={"poll"}, identity_resolver=lambda c: seen.append(1) or {}
+        )
+        await call(app, mw, ("poll", {}))
+        assert seen == []
+
+
+class TestSampling:
+    async def test_recorded_when_random_below_rate(self):
+        rolls = Rolls(0.29, 0.3, 0.31, 0.0)
+        app, sink, mw = make_app(sample_rates={"poll": 0.3}, random=rolls)
+        await call(app, mw, *[("poll", {})] * 4)
+        assert rolls.calls == 4
+        assert len(sink.records) == 2
+        assert [r.sample_rate for r in sink.records] == [0.3, 0.3]
+        assert all(r.outcome == "ok" for r in sink.records)
+
+    async def test_sampled_out_calls_not_in_recent(self):
+        app, sink, mw = make_app(sample_rates={"poll": 0.5}, random=Rolls(0.9, 0.1))
+        results = await call(app, mw, ("poll", {}), ("poll", {}))
+        assert len(sink.records) == 1
+        assert [r.id for r in mw.recent] == [sink.records[0].id]
+        # A sampled-out call still returns its result.
+        assert results[0].structured_content == {"status": "idle"}
+
+    async def test_sampled_out_ok_calls_skip_enricher(self):
+        # The identity resolver runs before the tool, when sampling cannot
+        # know yet whether the call will fail or record events; the enricher
+        # runs after, and only for calls that are kept.
+        seen = []
+
+        def who(context):
+            seen.append("identity")
+            return {}
+
+        def enrich(tool, args, result, context):
+            seen.append("enrich")
+            return {}
+
+        app, sink, mw = make_app(
+            sample_rates={"poll": 0.1},
+            random=Rolls(0.99),
+            identity_resolver=who,
+            enricher=enrich,
+        )
+        await call(app, mw, ("poll", {}))
+        assert sink.records == []
+        assert seen == ["identity"]
+
+    async def test_unsampled_tools_recorded_without_rate_or_roll(self):
+        rolls = Rolls()
+        app, sink, mw = make_app(sample_rates={"poll": 0.1}, random=rolls)
+        await call(app, mw, ("other", {}), ("other", {}))
+        assert rolls.calls == 0
+        assert [(r.tool, r.sample_rate) for r in sink.records] == [
+            ("other", None),
+            ("other", None),
+        ]
+
+    async def test_rate_of_one_records_everything_with_rate(self):
+        app, sink, mw = make_app(sample_rates={"poll": 1}, random=Rolls(0.999))
+        await call(app, mw, ("poll", {}))
+        [record] = sink.records
+        assert record.sample_rate == 1.0
+
+    async def test_exception_of_sampled_tool_always_recorded(self):
+        # Rolls would sample every call out; failures must not consult them.
+        rolls = Rolls(0.99, 0.99)
+        app, sink, mw = make_app(sample_rates={"crash": 0.01}, random=rolls)
+        await call(app, mw, ("crash", {}), ("crash", {}))
+        assert [(r.outcome, r.error_type, r.sample_rate) for r in sink.records] == [
+            ("error", "RuntimeError", None),
+            ("error", "RuntimeError", None),
+        ]
+        assert len(mw.recent) == 2
+
+    async def test_soft_error_of_sampled_tool_always_recorded(self):
+        rolls = Rolls(0.99, 0.99)
+        app, sink, mw = make_app(sample_rates={"render": 0.01}, random=rolls)
+        await call(
+            app, mw, ("render", {"status": "failed"}), ("render", {"status": "done"})
+        )
+        assert [(r.outcome, r.sample_rate) for r in sink.records] == [
+            ("soft_error", None)
+        ]
+        assert sink.records[0].error_message == "status=failed: render said failed"
+        assert [r.id for r in mw.recent] == [sink.records[0].id]
+
+    async def test_sampled_in_failure_has_no_rate(self):
+        app, sink, mw = make_app(sample_rates={"crash": 0.5}, random=Rolls(0.0))
+        await call(app, mw, ("crash", {}))
+        [record] = sink.records
+        assert record.sample_rate is None
+
+    @pytest.mark.parametrize("rate", [0, -0.1, 1.01, 2, float("nan")])
+    def test_invalid_rates_rejected(self, rate):
+        with pytest.raises(ValueError, match="poll"):
+            make_app(sample_rates={"poll": rate})
+
+    def test_non_numeric_rate_rejected(self):
+        with pytest.raises((TypeError, ValueError)):
+            make_app(sample_rates={"poll": "often"})
+
+    async def test_estimated_count(self):
+        """sum(1 / coalesce(sample_rate, 1)) estimates the true call count."""
+        rolls = Rolls(*[i / 10 for i in range(10)])
+        app, sink, mw = make_app(sample_rates={"poll": 0.2}, random=rolls)
+        await call(app, mw, *[("poll", {})] * 10, ("crash", {}))
+        estimate = sum(1 / (r.sample_rate or 1) for r in sink.records)
+        assert estimate == pytest.approx(11)
+
+
+class TestDatabaseSinkColumn:
+    async def test_writes_sample_rate(self, db):
+        sink = db()
+        app, _, mw = make_app(
+            sinks=[sink],
+            sample_rates={"poll": 0.25, "crash": 0.25},
+            random=Rolls(0.1, 0.9),
+        )
+        await call(app, mw, ("poll", {}), ("poll", {}), ("crash", {}), ("other", {}))
+        assert await rows(sink, "tool", "outcome", "sample_rate") == [
+            ("poll", "ok", 0.25),
+            ("crash", "error", None),
+            ("other", "ok", None),
+        ]
+
+
+class TestPrune:
+    async def test_deletes_old_rows_keeps_new(self, db):
+        sink = db()
+        await sink.write([old_record("a", days=40), old_record("b", days=31)])
+        await sink.write([old_record("c", days=29), old_record("d", days=0)])
+        deleted = await sink.prune(datetime.now(UTC) - timedelta(days=30))
+        assert deleted == 2
+        assert await rows(sink) == [("c",), ("d",)]
+
+    async def test_default_cutoff_uses_retention(self, db):
+        sink = db(retention=timedelta(days=30))
+        sink._last_prune = time.monotonic()  # keep write() from pruning
+        await sink.write([old_record("a", days=40), old_record("b", days=1)])
+        assert await count(sink) == 2
+        assert await sink.prune() == 1
+        assert await rows(sink) == [("b",)]
+
+    async def test_no_retention_no_cutoff_is_a_no_op(self, db):
+        sink = db()
+        await sink.write([old_record(days=400)])
+        assert await sink.prune() == 0
+        assert await count(sink) == 1
+
+    async def test_keeps_linked_calls_and_links(self, db):
+        sink = db()
+        linked, plain = old_record("linked"), old_record("plain")
+        await sink.write([linked, plain])
+        await sink.replace_links(
+            "bug-1",
+            [
+                {
+                    "feedback_ref": "bug-1",
+                    "call_id": linked.id,
+                    "position": 0,
+                    "rule": "session",
+                    "linked_at": datetime.now(UTC),
+                },
+                {
+                    # A link to a call that is not in this database.
+                    "feedback_ref": "bug-1",
+                    "call_id": "missing",
+                    "position": 1,
+                    "rule": "session",
+                    "linked_at": datetime.now(UTC),
+                },
+            ],
+        )
+        assert await sink.prune(datetime.now(UTC)) == 1
+        assert await rows(sink) == [("linked",)]
+        context = await sink.linked_calls("bug-1")
+        assert [(r["call_id"], r["tool"]) for r in context] == [
+            (linked.id, "linked"),
+            ("missing", None),
+        ]
+
+    async def test_deletes_in_batches(self, db):
+        sink = db(prune_batch=3)
+        await sink.write(
+            [old_record(f"t{i}") for i in range(10)] + [old_record("new", 0)]
+        )
+        deletes = []
+
+        def spy(conn, cursor, statement, params, context, executemany):
+            if statement.lstrip().upper().startswith("DELETE"):
+                deletes.append(statement)
+
+        event.listen(sink.engine.sync_engine, "before_cursor_execute", spy)
+        try:
+            assert await sink.prune(datetime.now(UTC) - timedelta(days=1)) == 10
+        finally:
+            event.remove(sink.engine.sync_engine, "before_cursor_execute", spy)
+        assert len(deletes) == 4  # 3 + 3 + 3 + 1
+        assert await rows(sink) == [("new",)]
+
+    async def test_exact_multiple_of_batch(self, db):
+        sink = db(prune_batch=5)
+        await sink.write([old_record(f"t{i}") for i in range(10)])
+        assert await sink.prune(datetime.now(UTC)) == 10
+        assert await count(sink) == 0
+
+    def test_invalid_settings_rejected(self):
+        with pytest.raises(ValueError):
+            DatabaseSink("sqlite+aiosqlite://", retention=timedelta(0))
+        with pytest.raises(ValueError):
+            DatabaseSink("sqlite+aiosqlite://", prune_batch=0)
+
+
+class TestAutomaticPrune:
+    async def test_first_write_prunes_then_waits_for_interval(self, db):
+        sink = db(retention=timedelta(days=30), prune_interval=timedelta(hours=1))
+        await sink.write([old_record("a"), old_record("new", 0)])
+        assert await rows(sink) == [("new",)]
+
+        await sink.write([old_record("b")])
+        assert await count(sink) == 2  # inside the interval: not pruned
+
+        sink._last_prune = time.monotonic() - 3601
+        await sink.write([old_record("c", 0)])
+        assert sorted(await rows(sink)) == [("c",), ("new",)]
+
+    async def test_no_retention_never_prunes(self, db):
+        sink = db()
+        await sink.write([old_record(days=4000)])
+        assert await count(sink) == 1
+        assert sink._last_prune is None
+
+    async def test_failing_prune_does_not_stop_inserts(self, db, caplog):
+        sink = db(retention=timedelta(days=30))
+        attempts = []
+
+        async def broken(older_than=None):
+            attempts.append(older_than)
+            raise RuntimeError("prune blew up")
+
+        sink.prune = broken
+        with caplog.at_level(logging.WARNING):
+            await sink.write([old_record("a", 0)])
+            await sink.write([old_record("b", 0)])
+        assert await rows(sink) == [("a",), ("b",)]
+        assert len(attempts) == 1  # not retried on every write
+        assert "prune blew up" in caplog.text
+
+    async def test_through_the_middleware(self, db):
+        sink = db(retention=timedelta(days=30))
+        sink._last_prune = time.monotonic()
+        await sink.write([old_record("stale")])
+        sink._last_prune = None
+        app, _, mw = make_app(sinks=[sink])
+        await call(app, mw, ("other", {}))
+        assert mw.dispatcher.sink_errors == 0
+        assert await rows(sink) == [("other",)]
+
+    async def test_prune_failure_through_middleware_keeps_records(self, db):
+        sink = db(retention=timedelta(days=30))
+
+        async def broken(older_than=None):
+            raise RuntimeError("no")
+
+        sink.prune = broken
+        app, _, mw = make_app(sinks=[sink])
+        await call(app, mw, ("other", {}), ("poll", {}))
+        assert mw.dispatcher.sink_errors == 0
+        assert sorted(await rows(sink)) == [("other",), ("poll",)]

tests/unit/test_soft_errors.py

@@ -0,0 +1,551 @@
+"""Tests for classifying error results that tools return instead of raising.
+
+Real FastMCP servers through fastmcp.Client, as in test_instrumentation.py.
+"""
+
+import contextlib
+import logging
+
+import pytest
+from fastmcp import Client, FastMCP
+from fastmcp.exceptions import ToolError
+from mcp.types import CallToolResult, TextContent
+from sqlalchemy import select
+
+from fastmcp_feedback import add_feedback_tools
+from fastmcp_feedback.instrumentation import (
+    DEFAULT_RESULT_CLASSIFIER,
+    REDACTED,
+    DatabaseSink,
+    MemorySink,
+    ToolCallRecord,
+    instrument,
+    soft_error_classifier,
+)
+from fastmcp_feedback.mixins import submission
+
+BMCP_TOKEN = "bmcp_" + "A1b2C3d4E5f6G7h8I9j0"
+
+try:
+    from fastmcp.tools.tool import ToolResult
+except ImportError:  # FastMCP 4
+    from fastmcp.tools import ToolResult
+
+try:
+    ToolResult(content=[TextContent(type="text", text="x")], is_error=True)
+    TOOL_RESULT_IS_ERROR = True
+except TypeError:  # added in FastMCP 3.4
+    TOOL_RESULT_IS_ERROR = False
+
+
+@pytest.fixture
+async def db(db_url):
+    """DatabaseSinks whose engines are always disposed, or the process hangs."""
+    made = []
+
+    def factory(name="calls"):
+        sink = DatabaseSink(db_url(name), create_tables=True)
+        made.append(sink)
+        return sink
+
+    yield factory
+    for sink in made:
+        await sink.engine.dispose()
+
+
+def make_app(sinks=None, **kwargs):
+    sink = MemorySink()
+    app = FastMCP("soft")
+
+    @app.tool
+    def render(status: str) -> dict:
+        return {"status": status, "detail": f"render said {status}"}
+
+    @app.tool
+    def respond(payload: dict) -> dict:
+        return payload
+
+    @app.tool
+    def text(value: str) -> str:
+        return value
+
+    @app.tool
+    def items() -> list:
+        return [{"status": "failed"}]
+
+    @app.tool
+    def crash() -> dict:
+        raise RuntimeError("exploded")
+
+    @app.tool
+    def mcp_error() -> CallToolResult:
+        return CallToolResult(
+            content=[TextContent(type="text", text="target missing")], isError=True
+        )
+
+    mw = instrument(app, sinks if sinks is not None else [sink], **kwargs)
+    return app, sink, mw
+
+
+async def run(app, mw, tool, args=None):
+    async with Client(app) as client:
+        with contextlib.suppress(ToolError):
+            await client.call_tool(tool, args or {})
+    await mw.flush()
+
+
+async def record_for(tool, args=None, **kwargs) -> ToolCallRecord:
+    app, sink, mw = make_app(**kwargs)
+    await run(app, mw, tool, args)
+    [record] = sink.records
+    return record
+
+
+class TestClassifier:
+    @pytest.mark.parametrize(
+        "result, expected",
+        [
+            ({"status": "failed", "error": "disk full"}, "status=failed: disk full"),
+            ({"state": "ERROR"}, "state=ERROR"),
+            ({"ok": False, "message": "no scene"}, "ok=False: no scene"),
+            ({"success": False, "error": "nope"}, "success=False: nope"),
+            ({"success": False, "detail": "d", "reason": "r"}, "success=False: d"),
+            (
+                {"status": "failure", "error": {"code": 7, "message": "inner"}},
+                "status=failure: inner",
+            ),
+            ({"isError": True, "content": ["boom"]}, "isError: boom"),
+            (
+                {"is_error": True, "content": [{"type": "text", "text": "a"}]},
+                "isError: a",
+            ),
+            # mcspeak's failures: an error string and no status or flag key.
+            (
+                {"played": False, "error": "audio output stalled after 30s"},
+                "error: audio output stalled after 30s",
+            ),
+            (
+                {"error": "Not listening: microphone stopped"},
+                "error: Not listening: microphone stopped",
+            ),
+            ({"error": "  padded  "}, "error: padded"),
+            ({"status": "unhealthy", "error": "db gone"}, "error: db gone"),
+            # Earlier checks still win, with their own message.
+            ({"success": False, "error": "x"}, "success=False: x"),
+        ],
+    )
+    def test_flagged(self, result, expected):
+        assert DEFAULT_RESULT_CLASSIFIER("t", result) == expected
+
+    @pytest.mark.parametrize(
+        "result",
+        [
+            {"status": "done"},
+            {"status": "unknown_target"},
+            {"ok": True},
+            {"ok": 0},
+            {"success": None},
+            {"result": False},
+            {"state": 3},
+            {"isError": False},
+            {"played": True, "error": None},
+            {"error": ""},
+            {"error": "   "},
+            {"error": 0.02},
+            {"error": 0},
+            {"error": False},
+            # A structured error is left to custom classifiers.
+            {"error": {"code": 1}},
+            {"error": ["a"]},
+            {"failure_reason": "x"},
+            [{"status": "failed"}],
+            "failed",
+            None,
+        ],
+    )
+    def test_not_flagged(self, result):
+        assert DEFAULT_RESULT_CLASSIFIER("t", result) is None
+
+    def test_extra_statuses(self):
+        classify = soft_error_classifier(extra_statuses=("unknown_target",))
+        assert (
+            classify("t", {"status": "unknown_target", "error": "no cube"})
+            == "status=unknown_target: no cube"
+        )
+        assert classify("t", {"status": "failed"}) == "status=failed"
+
+    def test_custom_keys_replace_defaults(self):
+        classify = soft_error_classifier(
+            statuses=("bad",), status_keys=("phase",), flag_keys=("passed",)
+        )
+        assert classify("t", {"phase": "bad"}) == "phase=bad"
+        assert classify("t", {"passed": False}) == "passed=False"
+        assert classify("t", {"status": "failed", "ok": False}) is None
+
+    def test_unknown_status_with_error_string(self):
+        """blender-mcp's shape: flagged by default, labelled by status when known."""
+        result = {"status": "unknown_target", "error": "no object named Cube"}
+        assert DEFAULT_RESULT_CLASSIFIER("t", result) == "error: no object named Cube"
+        classify = soft_error_classifier(extra_statuses=("unknown_target",))
+        assert classify("t", result) == "status=unknown_target: no object named Cube"
+
+    def test_custom_error_keys(self):
+        classify = soft_error_classifier(error_keys=("failure_reason",))
+        assert classify("t", {"failure_reason": "no gpu"}) == "failure_reason: no gpu"
+        assert classify("t", {"error": "ignored"}) is None
+        assert classify("t", {"failure_reason": ""}) is None
+
+    def test_empty_error_keys_disable(self):
+        classify = soft_error_classifier(error_keys=())
+        assert classify("t", {"played": False, "error": "stalled"}) is None
+        assert classify("t", {"ok": False, "error": "x"}) == "ok=False: x"
+
+
+class TestExplicitSuccess:
+    """A flag key that is exactly True turns an error string into a warning."""
+
+    @pytest.mark.parametrize(
+        "result",
+        [
+            {"ok": True, "error": "deprecated arg"},
+            {"success": True, "error": "x"},
+            {"ok": True, "status": "unknown_target", "error": "fell back"},
+        ],
+    )
+    def test_true_flag_with_error_string_is_ok(self, result):
+        assert DEFAULT_RESULT_CLASSIFIER("t", result) is None
+
+    @pytest.mark.parametrize(
+        "result, expected",
+        [
+            ({"ok": False, "error": "x"}, "ok=False: x"),
+            # Not exactly True, so not an explicit success.
+            ({"ok": 1, "error": "x"}, "error: x"),
+            ({"ok": "yes", "error": "x"}, "error: x"),
+            ({"success": 1.0, "error": "x"}, "error: x"),
+            # No flag key: mcspeak's shape, as in 2026.10.01.
+            (
+                {"played": False, "error": "audio output stalled"},
+                "error: audio output stalled",
+            ),
+            # A False flag beats a True one.
+            ({"ok": True, "success": False, "error": "x"}, "success=False: x"),
+            # A failing status is more specific than the flag, so it still flags.
+            ({"success": True, "status": "failed"}, "status=failed"),
+            ({"ok": True, "state": "error", "error": "x"}, "state=error: x"),
+            ({"ok": True, "isError": True, "content": ["boom"]}, "isError: boom"),
+        ],
+    )
+    def test_still_flagged(self, result, expected):
+        assert DEFAULT_RESULT_CLASSIFIER("t", result) == expected
+
+    def test_custom_flag_keys(self):
+        classify = soft_error_classifier(flag_keys=("passed",))
+        assert classify("t", {"passed": True, "error": "slow"}) is None
+        assert classify("t", {"passed": False, "error": "x"}) == "passed=False: x"
+        # ok is not a flag key here, so it does not suppress the error check.
+        assert classify("t", {"ok": True, "error": "x"}) == "error: x"
+
+    def test_no_flag_keys(self):
+        classify = soft_error_classifier(flag_keys=())
+        assert classify("t", {"ok": True, "error": "x"}) == "error: x"
+
+    async def test_recorded_as_ok(self):
+        record = await record_for(
+            "respond", {"payload": {"ok": True, "error": "deprecated arg"}}
+        )
+        assert (record.outcome, record.ok, record.error_message) == ("ok", True, None)
+
+    async def test_truthy_flag_recorded_as_soft_error(self):
+        record = await record_for("respond", {"payload": {"ok": 1, "error": "x"}})
+        assert (record.outcome, record.ok, record.error_message) == (
+            "soft_error",
+            False,
+            "error: x",
+        )
+
+
+class TestMiddleware:
+    async def test_status_failed_is_soft_error(self):
+        record = await record_for("render", {"status": "failed"})
+        assert (record.outcome, record.ok, record.error_type) == (
+            "soft_error",
+            False,
+            "SoftError",
+        )
+        assert record.error_message == "status=failed: render said failed"
+
+    @pytest.mark.parametrize("key", ["ok", "success"])
+    async def test_false_flags_are_soft_errors(self, key):
+        record = await record_for("respond", {"payload": {key: False, "error": "x"}})
+        assert (record.outcome, record.ok) == ("soft_error", False)
+        assert record.error_message == f"{key}=False: x"
+
+    async def test_message_is_redacted_and_truncated(self):
+        record = await record_for(
+            "respond",
+            {"payload": {"status": "error", "error": f"bad key {BMCP_TOKEN} " * 50}},
+            max_error_chars=60,
+        )
+        assert BMCP_TOKEN not in record.error_message
+        assert REDACTED in record.error_message
+        assert len(record.error_message) == 60
+
+    async def test_error_string_is_soft_error(self):
+        record = await record_for(
+            "respond",
+            {"payload": {"played": False, "error": f"stalled, key {BMCP_TOKEN}"}},
+        )
+        assert (record.outcome, record.ok, record.error_type) == (
+            "soft_error",
+            False,
+            "SoftError",
+        )
+        assert record.error_message == f"error: stalled, key {REDACTED}"
+
+    @pytest.mark.parametrize("value", [None, "", 0.02])
+    async def test_empty_or_numeric_error_stays_ok(self, value):
+        record = await record_for(
+            "respond", {"payload": {"played": True, "error": value}}
+        )
+        assert (record.outcome, record.ok, record.error_message) == ("ok", True, None)
+
+    async def test_error_keys_disabled(self):
+        record = await record_for(
+            "respond",
+            {"payload": {"error": "stalled"}},
+            result_classifier=soft_error_classifier(error_keys=()),
+        )
+        assert (record.outcome, record.ok) == ("ok", True)
+
+    async def test_extra_statuses(self):
+        record = await record_for(
+            "render",
+            {"status": "unknown_target"},
+            result_classifier=soft_error_classifier(extra_statuses=("unknown_target",)),
+        )
+        assert record.outcome == "soft_error"
+        assert (
+            record.error_message == "status=unknown_target: render said unknown_target"
+        )
+
+    async def test_unknown_status_is_ok_by_default(self):
+        record = await record_for("render", {"status": "unknown_target"})
+        assert (record.outcome, record.ok, record.error_type) == ("ok", True, None)
+
+    @pytest.mark.parametrize(
+        "tool, args",
+        [
+            ("text", {"value": "failed"}),
+            ("items", {}),
+            ("respond", {"payload": {"status": "done", "count": 3}}),
+        ],
+    )
+    async def test_normal_results_stay_ok(self, tool, args):
+        record = await record_for(tool, args)
+        assert (record.outcome, record.ok, record.error_message) == ("ok", True, None)
+
+    async def test_none_disables(self):
+        record = await record_for(
+            "render", {"status": "failed"}, result_classifier=None
+        )
+        assert (record.outcome, record.ok, record.error_type) == ("ok", True, None)
+
+    async def test_custom_classifier(self):
+        seen = []
+
+        def classify(tool, result):
+            seen.append((tool, result))
+            return "empty" if result.get("count") == 0 else None
+
+        record = await record_for(
+            "respond", {"payload": {"count": 0}}, result_classifier=classify
+        )
+        assert seen == [("respond", {"count": 0})]
+        assert (record.outcome, record.error_message) == ("soft_error", "empty")
+
+    async def test_raising_classifier_records_ok(self, caplog):
+        def classify(tool, result):
+            raise KeyError("classifier bug")
+
+        app, sink, mw = make_app(result_classifier=classify)
+        with caplog.at_level(logging.WARNING):
+            async with Client(app) as client:
+                result = await client.call_tool("render", {"status": "failed"})
+            await mw.flush()
+        assert result.data["status"] == "failed"
+        [record] = sink.records
+        assert (record.outcome, record.ok, record.error_type) == ("ok", True, None)
+        assert "Result classifier" in caplog.text
+
+    async def test_classifier_not_run_on_exceptions(self):
+        calls = []
+        record = await record_for(
+            "crash", result_classifier=lambda t, r: calls.append(t) or "x"
+        )
+        assert calls == []
+        assert (record.outcome, record.ok, record.error_type) == (
+            "error",
+            False,
+            "RuntimeError",
+        )
+        assert record.error_message == "exploded"
+
+    async def test_mcp_error_result_without_raising(self):
+        """A CallToolResult with isError, on every FastMCP version."""
+        record = await record_for("mcp_error")
+        assert (record.outcome, record.ok) == ("soft_error", False)
+        assert record.error_message == "isError: target missing"
+
+    @pytest.mark.skipif(not TOOL_RESULT_IS_ERROR, reason="ToolResult.is_error is 3.4+")
+    async def test_tool_result_is_error(self):
+        app = FastMCP("is_error")
+
+        @app.tool
+        def lookup():
+            return ToolResult(
+                content=[TextContent(type="text", text="not found")], is_error=True
+            )
+
+        sink = MemorySink()
+        mw = instrument(app, [sink])
+        async with Client(app) as client:
+            await client.call_tool("lookup", {}, raise_on_error=False)
+        await mw.flush()
+        [record] = sink.records
+        assert (record.outcome, record.error_message) == (
+            "soft_error",
+            "isError: not found",
+        )
+
+    def test_record_outcome_defaults_from_ok(self):
+        from datetime import UTC, datetime
+
+        now = datetime.now(UTC)
+        assert ToolCallRecord("t", now, 1.0, True, "meta").outcome == "ok"
+        assert ToolCallRecord("t", now, 1.0, False, "meta").outcome == "error"
+
+
+class TestStorageAndCorrelation:
+    async def test_database_sink_writes_outcome(self, db):
+        sink = db()
+        app, _, mw = make_app(sinks=[sink])
+        async with Client(app) as client:
+            await client.call_tool("render", {"status": "done"})
+            await client.call_tool("render", {"status": "failed"})
+            with contextlib.suppress(ToolError):
+                await client.call_tool("crash", {})
+        await mw.flush()
+
+        t = sink.table
+        async with sink.engine.connect() as conn:
+            rows = (
+                await conn.execute(
+                    select(t.c.outcome, t.c.ok, t.c.error_type).order_by(t.c.started_at)
+                )
+            ).all()
+        assert [tuple(r) for r in rows] == [
+            ("ok", True, None),
+            ("soft_error", False, "SoftError"),
+            ("error", False, "RuntimeError"),
+        ]
+        async with sink.engine.connect() as conn:
+            [(failing,)] = (
+                await conn.execute(
+                    select(t.c.tool).where(~t.c.ok, t.c.outcome != "error")
+                )
+            ).all()
+        assert failing == "render"
+
+    async def test_links_and_feedback_context_show_soft_errors(self, db):
+        app, _, mw = make_app(
+            sinks=[db()], identity_resolver=lambda c: {"user_sub": "u1"}
+        )
+        captured = {}
+
+        @app.tool
+        async def report() -> int:
+            captured["links"] = await mw.capture_recent_calls()
+            await mw.link_feedback("bug-1", captured["links"])
+            return len(captured["links"])
+
+        async with Client(app) as client:
+            await client.call_tool("render", {"status": "failed"})
+            await client.call_tool("report", {})
+
+        links = captured["links"]
+        assert [(link.tool, link.ok) for link in links] == [("render", False)]
+        # Filled from memory or read from the database, depending on timing.
+        [row] = await mw.feedback_context("bug-1")
+        assert (row["outcome"], row["ok"], row["error_type"]) == (
+            "soft_error",
+            False,
+            "SoftError",
+        )
+        await mw.flush()
+        [row] = await mw.feedback_context("bug-1")
+        assert (row["tool"], row["outcome"], row["ok"]) == (
+            "render",
+            "soft_error",
+            False,
+        )
+        await mw.aclose()
+
+    async def test_submit_feedback_failure_is_soft_error(self, monkeypatch):
+        def broken(request):
+            raise RuntimeError("database down, password=hunter2")
+
+        monkeypatch.setattr(submission, "create_feedback_from_request", broken)
+        app = FastMCP("fb")
+        sink = MemorySink()
+        mw = instrument(app, [sink])
+        add_feedback_tools(app, database_url="sqlite:///:memory:", instrumentation=mw)
+
+        async with Client(app) as client:
+            result = await client.call_tool(
+                "submit_feedback",
+                {
+                    "request": {
+                        "type": "bug",
+                        "title": "t",
+                        "description": "d",
+                        "submitter": "m",
+                    }
+                },
+            )
+        await mw.flush()
+        assert result.data["success"] is False
+        [record] = sink.records
+        assert (record.tool, record.outcome, record.ok, record.error_type) == (
+            "submit_feedback",
+            "soft_error",
+            False,
+            "SoftError",
+        )
+        assert record.error_message == (
+            f"success=False: database down, password={REDACTED}"
+        )
+
+    async def test_list_feedback_failure_is_soft_error(self, monkeypatch):
+        """list_feedback reports failure as {"feedback": [], "error": ...}."""
+        app = FastMCP("fb")
+        sink = MemorySink()
+        mw = instrument(app, [sink])
+        add_feedback_tools(app, database_url="sqlite:///:memory:", instrumentation=mw)
+
+        def broken(*args, **kwargs):
+            raise RuntimeError("database down")
+
+        from fastmcp_feedback.database import FeedbackDatabase
+
+        monkeypatch.setattr(FeedbackDatabase, "session", broken)
+        async with Client(app) as client:
+            result = await client.call_tool("list_feedback", {})
+        await mw.flush()
+        assert result.data["error"] == "database down"
+        [record] = sink.records
+        assert (record.tool, record.outcome, record.error_message) == (
+            "list_feedback",
+            "soft_error",
+            "error: database down",
+        )

tests/unit/test_test_databases.py

@@ -0,0 +1,70 @@
+"""Checks on the db_url fixture itself: isolation between tests, and pgvector."""
+
+from datetime import UTC, datetime
+
+import pytest
+from sqlalchemy import func, select, text
+
+from fastmcp_feedback.instrumentation import DatabaseSink, ToolCallRecord
+
+SHARED_ID = "00000000-0000-0000-0000-00000000f00d"
+
+
+@pytest.fixture
+async def sink(db_url):
+    made = DatabaseSink(db_url(), create_tables=True)
+    yield made
+    await made.engine.dispose()
+
+
+async def write_fixed_row(sink):
+    """Insert a row with a fixed primary key and return the table's row count.
+
+    Two tests that did this against one shared database would collide on the
+    key, so each passing proves it had a database of its own.
+    """
+    rec = ToolCallRecord(
+        id=SHARED_ID,
+        tool="t",
+        started_at=datetime.now(UTC),
+        duration_ms=1.0,
+        ok=True,
+        mode="meta",
+    )
+    await sink.write([rec])
+    async with sink.engine.connect() as conn:
+        return (
+            await conn.execute(select(func.count()).select_from(sink.table))
+        ).scalar()
+
+
+class TestIsolation:
+    async def test_first_writer(self, sink):
+        assert await write_fixed_row(sink) == 1
+
+    async def test_second_writer(self, sink):
+        assert await write_fixed_row(sink) == 1
+
+    def test_names_map_to_databases(self, db_url):
+        assert db_url("a") == db_url("a")
+        assert db_url("a") != db_url("b")
+
+
+async def test_vector_extension_available(db_url, db_backend):
+    if db_backend != "postgres":
+        pytest.skip("pgvector is Postgres only")
+    sink = DatabaseSink(db_url())
+    try:
+        async with sink.engine.connect() as conn:
+            version = (
+                await conn.execute(
+                    text("SELECT extversion FROM pg_extension WHERE extname = 'vector'")
+                )
+            ).scalar()
+            distance = (
+                await conn.execute(text("SELECT '[1,2,3]'::vector <-> '[1,2,4]'"))
+            ).scalar()
+    finally:
+        await sink.engine.dispose()
+    assert version is not None
+    assert distance == 1.0

tests/unit/test_tools.py

@@ -7,6 +7,7 @@ from fastmcp import FastMCP
 from fastmcp_feedback.tools import add_feedback_tools
 from fastmcp_feedback.feedback import create_feedback_server
 from fastmcp_feedback.models import SubmitFeedbackRequest
+from tests._compat import tool_map
 
 
 @pytest.mark.unit
@@ -18,7 +19,7 @@ class TestAddFeedbackTools:
         """Test adding feedback tools with basic configuration."""
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         expected_tools = [
@@ -40,7 +41,7 @@ class TestAddFeedbackTools:
             prefix="support"
         )
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         expected_tools = [
@@ -62,7 +63,7 @@ class TestAddFeedbackTools:
             insights=test_insights
         )
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         
         # Should have all standard tools - check tool names in the keys
         assert len([name for name in tools.keys() if "feedback" in name]) >= 5
@@ -76,7 +77,7 @@ class TestAddFeedbackTools:
         # Should use default SQLite database
         add_feedback_tools(mock_fastmcp_server)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         assert "submit_feedback" in tool_names
@@ -91,7 +92,7 @@ class TestAddFeedbackTools:
             separator="-"
         )
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         assert "api-submit_feedback" in tool_names
@@ -105,7 +106,7 @@ class TestAddFeedbackTools:
         # Second call with different prefix
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url, prefix="user")
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         # Should have tools with both prefixes
@@ -128,7 +129,7 @@ class TestCreateFeedbackServer:
         assert isinstance(server, FastMCP)
         assert server.name == "Test Feedback Server"
         
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         tool_names = list(tools.keys())
         
         expected_tools = [
@@ -150,7 +151,7 @@ class TestCreateFeedbackServer:
         )
         
         assert server.name == "Custom DB Server"
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         assert len(tools) >= 5
     
     async def test_create_feedback_server_with_insights(self, test_insights):
@@ -162,7 +163,7 @@ class TestCreateFeedbackServer:
         
         assert server.name == "Analytics Server"
         # Verify insights are integrated
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         assert len(tools) >= 5
     
     async def test_create_feedback_server_with_description(self):
@@ -184,8 +185,8 @@ class TestCreateFeedbackServer:
         assert server1.name != server2.name
         
         # Each should have independent tool sets
-        tools1 = await server1.get_tools()
-        tools2 = await server2.get_tools()
+        tools1 = await tool_map(server1)
+        tools2 = await tool_map(server2)
         
         assert len(tools1) >= 5
         assert len(tools2) >= 5
@@ -201,7 +202,7 @@ class TestToolIntegration:
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
         # Get the submit_feedback tool
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         submit_tool = tools["submit_feedback"]
         
         assert submit_tool is not None
@@ -218,7 +219,7 @@ class TestToolIntegration:
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
         # Get the list_feedback tool
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         list_tool = tools["list_feedback"]
         
         assert list_tool is not None
@@ -234,7 +235,7 @@ class TestToolIntegration:
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
         # Get the statistics tool
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         stats_tool = tools["get_feedback_statistics"]
         
         assert stats_tool is not None
@@ -250,7 +251,7 @@ class TestToolIntegration:
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
         # Get the update status tool
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         update_tool = tools["update_feedback_status"]
         
         assert update_tool is not None
@@ -269,7 +270,7 @@ class TestToolIntegration:
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
         # Get the delete tool
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         delete_tool = tools["delete_feedback"]
         
         assert delete_tool is not None
@@ -290,7 +291,7 @@ class TestToolValidation:
         """Test submit_feedback tool parameter validation."""
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         submit_tool = tools["submit_feedback"]
         
         # Test with invalid parameters
@@ -301,7 +302,7 @@ class TestToolValidation:
         """Test list_feedback tool parameter validation."""
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         list_tool = tools["list_feedback"]
         
         # Test with valid optional parameters
@@ -318,7 +319,7 @@ class TestToolValidation:
         """Test update_feedback_status parameter validation."""
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         update_tool = tools["update_feedback_status"]
         
         # Test with missing required parameters
@@ -329,7 +330,7 @@ class TestToolValidation:
         """Test delete_feedback parameter validation."""
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         delete_tool = tools["delete_feedback"]
         
         # Test with missing required parameters
@@ -348,9 +349,9 @@ class TestServerComposition:
         feedback_server = create_feedback_server("Feedback Service")
         
         # Import feedback server with prefix
-        await main_server.import_server(feedback_server, prefix="feedback")
+        main_server.mount(feedback_server, "feedback")
         
-        tools = await main_server.get_tools()
+        tools = await tool_map(main_server)
         tool_names = list(tools.keys())
         
         # Should have feedback tools with prefix
@@ -364,10 +365,10 @@ class TestServerComposition:
         user_feedback = create_feedback_server("User Feedback")
         admin_feedback = create_feedback_server("Admin Feedback")
         
-        await main_server.import_server(user_feedback, prefix="user")
-        await main_server.import_server(admin_feedback, prefix="admin")
+        main_server.mount(user_feedback, "user")
+        main_server.mount(admin_feedback, "admin")
         
-        tools = await main_server.get_tools()
+        tools = await tool_map(main_server)
         tool_names = list(tools.keys())
         
         # Should have tools from both servers
@@ -386,9 +387,9 @@ class TestServerComposition:
         # Implementation would need to support this feature
         # FastMCP import_server doesn't support selective tool import
         # but we can test the full import with prefix
-        await main_server.import_server(feedback_server, prefix="public")
+        main_server.mount(feedback_server, "public")
         
-        tools = await main_server.get_tools()
+        tools = await tool_map(main_server)
         tool_names = list(tools.keys())
         
         # All tools should be imported with prefix
@@ -416,7 +417,7 @@ class TestToolPerformance:
         assert performance_timer.duration_ms < 1000  # 1 second
         
         # Verify all tools were registered
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         assert len(tools) >= 5
     
     async def test_multiple_server_creation_performance(self, performance_timer):
@@ -436,14 +437,14 @@ class TestToolPerformance:
         
         # Each server should be functional
         for server in servers:
-            tools = await server.get_tools()
+            tools = await tool_map(server)
             assert len(tools) >= 5
     
     async def test_tool_execution_performance(self, mock_fastmcp_server, memory_db_url, performance_timer):
         """Test performance of tool execution."""
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         list_tool = tools["list_feedback"]
         
         performance_timer.start()
@@ -467,7 +468,7 @@ class TestToolConfiguration:
         """Test that tools have proper descriptions."""
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         
         for tool_name, tool_obj in tools.items():
             # Each tool should have a description
@@ -480,7 +481,7 @@ class TestToolConfiguration:
         """Test tool metadata and categorization."""
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         feedback_tools = [name for name in tools.keys() if "feedback" in name]
         
         # Should have categorized the tools appropriately
@@ -490,7 +491,7 @@ class TestToolConfiguration:
         """Test tool parameter schemas."""
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         submit_tool = tools["submit_feedback"]
         
         # Tool should have parameter schema defined
@@ -510,7 +511,7 @@ class TestToolErrorHandling:
         # Use invalid database URL
         add_feedback_tools(server, database_url="sqlite:///nonexistent/path/db.sqlite")
         
-        tools = await server.get_tools()
+        tools = await tool_map(server)
         list_tool = tools["list_feedback"]
         
         # Tool execution should handle database errors gracefully
@@ -523,7 +524,7 @@ class TestToolErrorHandling:
         """Test tool handling of invalid parameters."""
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         submit_tool = tools["submit_feedback"]
         
         # Test with malformed request
@@ -534,7 +535,7 @@ class TestToolErrorHandling:
         """Test concurrent execution of tools."""
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         list_tool = tools["list_feedback"]
         
         import asyncio

tests/unit/test_tools_comprehensive.py

@@ -23,6 +23,7 @@ from fastmcp_feedback.tools import (
 )
 from fastmcp_feedback.database import FeedbackDatabase
 from fastmcp_feedback.insights import FeedbackInsights
+from tests._compat import tool_map
 
 
 @pytest.mark.unit
@@ -34,7 +35,7 @@ class TestSubmissionTools:
         """Test adding submission tools with basic configuration."""
         add_submission_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         # Should have submission-related tools
@@ -51,7 +52,7 @@ class TestSubmissionTools:
             prefix="user"
         )
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         assert "user_submit_feedback" in tool_names
@@ -65,14 +66,14 @@ class TestSubmissionTools:
             insights=test_insights
         )
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         assert len(tools) > 0
     
     async def test_add_submission_tools_without_database_url(self, mock_fastmcp_server):
         """Test adding submission tools without database URL (uses default)."""
         add_submission_tools(mock_fastmcp_server)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         assert "submit_feedback" in tools
     
     @patch('fastmcp_feedback.tools.FeedbackDatabase')
@@ -105,7 +106,7 @@ class TestSubmissionTools:
             prefix="api_"  # With trailing underscore
         )
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         # Should strip trailing underscore
@@ -121,7 +122,7 @@ class TestRetrievalTools:
         """Test adding retrieval tools with basic configuration."""
         add_retrieval_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         # Should have retrieval-related tools
@@ -139,7 +140,7 @@ class TestRetrievalTools:
             prefix="public"
         )
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         assert "public_list_feedback" in tool_names
@@ -154,14 +155,14 @@ class TestRetrievalTools:
             insights=test_insights
         )
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         assert len(tools) > 0
     
     async def test_add_retrieval_tools_without_database_url(self, mock_fastmcp_server):
         """Test adding retrieval tools without database URL (uses default)."""
         add_retrieval_tools(mock_fastmcp_server)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         assert "list_feedback" in tools
         assert "get_feedback_statistics" in tools
     
@@ -197,7 +198,7 @@ class TestManagementTools:
         """Test adding management tools with basic configuration."""
         add_management_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         # Should have management-related tools
@@ -215,7 +216,7 @@ class TestManagementTools:
             prefix="admin"
         )
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         assert "admin_update_feedback_status" in tool_names
@@ -230,14 +231,14 @@ class TestManagementTools:
             insights=test_insights
         )
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         assert len(tools) > 0
     
     async def test_add_management_tools_without_database_url(self, mock_fastmcp_server):
         """Test adding management tools without database URL (uses default)."""
         add_management_tools(mock_fastmcp_server)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         assert "update_feedback_status" in tools
         assert "delete_feedback" in tools
     
@@ -347,7 +348,7 @@ class TestAdvancedIntegrationPatterns:
         
         create_multi_tenant_tools(mock_fastmcp_server, tenants)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         # Should have tools for each tenant with prefixes
@@ -365,7 +366,7 @@ class TestAdvancedIntegrationPatterns:
         
         create_multi_tenant_tools(mock_fastmcp_server, tenants, insights=test_insights)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         assert len(tools) >= 10  # At least 5 tools per tenant
     
     async def test_create_multi_tenant_tools_empty_tenants(self, mock_fastmcp_server):
@@ -374,7 +375,7 @@ class TestAdvancedIntegrationPatterns:
         
         create_multi_tenant_tools(mock_fastmcp_server, tenants)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         # Should complete without error but not add any tools
         assert len(tools) == 0
     
@@ -394,7 +395,7 @@ class TestAdvancedIntegrationPatterns:
         """Test creating role-based tools."""
         create_role_based_tools(mock_fastmcp_server, database_url=memory_db_url)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         # Should have public tools (submission and retrieval)
@@ -416,14 +417,14 @@ class TestAdvancedIntegrationPatterns:
             insights=test_insights
         )
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         assert len(tools) >= 7  # Public + admin tools
     
     async def test_create_role_based_tools_without_database(self, mock_fastmcp_server):
         """Test creating role-based tools without database URL."""
         create_role_based_tools(mock_fastmcp_server)
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         assert "public_submit_feedback" in tool_names
@@ -465,7 +466,7 @@ class TestMigrationHelpers:
         mock_fastmcp_server.remove_tool.assert_any_call("old_list_tool")
         
         # Should have new tools added
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         assert "submit_feedback" in tool_names
         assert "list_feedback" in tool_names
@@ -501,7 +502,7 @@ class TestMigrationHelpers:
             insights=test_insights
         )
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         assert len(tools) >= 5
     
     async def test_migrate_tools_to_mixins_empty_list(self, mock_fastmcp_server, memory_db_url):
@@ -515,7 +516,7 @@ class TestMigrationHelpers:
         )
         
         # Should still add new tools
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         assert len(tools) >= 5
     
     @patch('fastmcp_feedback.tools.add_feedback_tools')
@@ -757,7 +758,7 @@ class TestErrorHandlingAndEdgeCases:
         
         # Verify all servers have tools
         for server in servers:
-            tools = await server.get_tools()
+            tools = await tool_map(server)
             assert "submit_feedback" in tools
             assert "public_list_feedback" in tools
             assert "admin_update_feedback_status" in tools
@@ -774,7 +775,7 @@ class TestErrorHandlingAndEdgeCases:
         # Multiple underscores
         add_management_tools(mock_fastmcp_server, database_url=memory_db_url, prefix="admin___")
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         # Should handle edge cases gracefully
@@ -812,7 +813,7 @@ class TestIntegrationWithExistingTests:
         # Add all tools
         add_feedback_tools(mock_fastmcp_server, database_url=memory_db_url, prefix="complete")
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         tool_names = list(tools.keys())
         
         # Should have both individual and complete sets
@@ -830,7 +831,7 @@ class TestIntegrationWithExistingTests:
             insights=test_insights
         )
         
-        tools = await mock_fastmcp_server.get_tools()
+        tools = await tool_map(mock_fastmcp_server)
         submit_tool = tools["submit_feedback"]
         
         # Should work with existing sample data
@@ -848,9 +849,9 @@ class TestIntegrationWithExistingTests:
         add_retrieval_tools(feedback_server, prefix="readonly")
         
         # Import with prefix
-        await main_server.import_server(feedback_server, prefix="external")
+        main_server.mount(feedback_server, "external")
         
-        tools = await main_server.get_tools()
+        tools = await tool_map(main_server)
         tool_names = list(tools.keys())
         
         # Should have properly composed tool names