diff --git a/pkg/api/flamenco-openapi.yaml b/pkg/api/flamenco-openapi.yaml
index 7a97294f..d683c63e 100644
--- a/pkg/api/flamenco-openapi.yaml
+++ b/pkg/api/flamenco-openapi.yaml
@@ -1431,11 +1431,25 @@ components:
         "priority": { type: integer, default: 50 }
         "settings": { $ref: "#/components/schemas/JobSettings" }
         "metadata": { $ref: "#/components/schemas/JobMetadata" }
-      required: [name, type, priority]
+        "submitter_platform":
+          type: string
+          description: >
+            Operating system of the submitter. This is used to recognise two-way
+            variables. This should be a lower-case version of the platform, like
+            "linux", "windows", "darwin", "openbsd", etc. Should be ompatible
+            with Go's `runtime.GOOS`; run `go tool dist list` to get a list of
+            possible platforms.
+
+            As a special case, the platform "manager" can be given, which will
+            be interpreted as "the Manager's platform". This is mostly to make
+            test/debug scripts easier, as they can use a static document on all
+            platforms.
+      required: [name, type, priority, submitter_platform]
       example:
         type: "simple-blender-render"
         name: 3Д рендеринг
         priority: 50
+        submitter_platform: linux
         settings:
           blender_cmd: "{blender}"
           filepath: "/render/sf/jobs/scene123.blend"