Ryan Malloy
c905032a39
Specctra's SpecCharASCII includes / and *, and an Identifier may start with /, so KiCad emits hierarchical net names such as /*52 and /53. The tokenizer treated any /* as a block-comment start and raised 'unterminated comment' when no */ followed — rejecting real KiCad DSN. Match FreeRouting's JFlex rule-order resolution: /* is a comment only when a closing */ exists; otherwise it is an ordinary name run. Validated against a KiCad 10.0.4 pcbnew-exported DSN (78 nets incl. /*52, /53).
freeroute
A native Python PCB autorouter — a Java-free port of the FreeRouting engine.
Why
kicad-mcp currently autoroutes by shelling out to freerouting.jar, which
drags in a JVM dependency. freeroute reimplements the routing engine in
pure Python so the toolchain needs no Java at all.
The contract
The entire integration surface is two Specctra files:
board.dsn ──▶ freeroute ──▶ board.ses
(unrouted) (routed session: traces + vias)
kicad-cli already exports .dsn and imports .ses, so freeroute is a
drop-in replacement for the JAR step — nothing else in the pipeline changes.
Status
Pre-alpha. Under active development. See docs/PORTING_PLAN.md
for the architecture and porting roadmap.
Usage (target)
freeroute board.dsn -o board.ses
Development
uv sync
uv run pytest
uv run ruff check src/ tests/
License
GPL-3.0-or-later, matching the FreeRouting source it is ported from.