Extension REST API (Swagger)

The StationeersLua VS Code extension talks to the game over plain HTTP REST on /api/*. This is separate from:

• The MCP JSON-RPC server on the same port (for AI editors)
• The in-game Lua ic.http client API (HTTP reference)

Enable the API

In BepInEx config, section [MCP Server]:

Setting	Required for REST
EnableExtensionApi	Yes — gates all /api/* routes
Port	Default 3030
BindAddress	Default 127.0.0.1 (localhost only)
EnableExperimentalDebugger	Only for /api/debug/* routes

Default base URL: http://127.0.0.1:3030

See also MCP Server & Reference Panel and VS Code Extension.

OpenAPI spec

The machine-readable spec is at /openapi/extension-api.yaml.

API reference

Route overview

Method	Path	Purpose
GET	/api/status	Health + version
GET	/api/editor	Editor selection and network scope
GET/PUT	/api/editor/code	Read/write IC editor draft (raw Lua body on PUT)
GET	/api/chips	List accessible chips
GET/PUT	/api/chips/{refId}/code	Read/write chip source
GET	/api/chips/{refId}/errors	Compile/runtime errors
POST	/api/debug/session	Create debugger session
GET/DELETE	/api/debug/session/{id}	Session state / close
GET	/api/debug/session/{id}/events	Poll debug events
GET	/api/debug/session/{id}/stack	Stack trace
GET	/api/debug/session/{id}/scopes	Scopes for a frame
GET	/api/debug/session/{id}/variables	Variables for a reference
POST	/api/debug/session/{id}/evaluate	Evaluate expression
POST	/api/debug/session/{id}/setVariable	Set variable
POST	/api/debug/session/{id}/completions	Completions
POST	/api/debug/session/{id}/breakpoints	Set breakpoints
POST	/api/debug/session/{id}/continue	Continue
POST	/api/debug/session/{id}/pause	Pause
POST	/api/debug/session/{id}/next	Step over
POST	/api/debug/session/{id}/stepin	Step in
POST	/api/debug/session/{id}/stepout	Step out
POST	/api/debug/session/{id}/restart	Restart session

Error semantics

• 403 — REST or debugger disabled in config
• 400 — Bridge returned success: false or an error string in JSON
• 404 — Unknown path
• 500 — Unhandled server error

Debug session JSON errors may include a structured reason field:

reason	Meaning
unknown_session	Session id is not registered (closed, timed out, or never created)
session_owned_by_other_client	Another multiplayer client owns this session

Code PUT endpoints (/api/editor/code, /api/chips/{refId}/code) expect text/plain raw Lua source, not a JSON wrapper.

Debug protocol notes

GET /api/status includes:

{
  "debugger_enabled": true,
  "debug_protocol": {
    "breakpoints_source_path": true,
    "event_seq": true,
    "session_timeout_seconds": 60
  }
}

• Breakpoints: POST .../breakpoints accepts optional request-level source_path and per-breakpoint source_path. Breakpoints are keyed by (source_path, line) so require()d modules do not collide with the main chunk. Omitting source_path falls back to the session’s attached source (legacy clients).
• Verification: each returned breakpoint includes verified (against the compiled prototype line table when available) and optional message.
• Events: each polled event includes a monotonic seq so the extension can detect gaps / ordering.
• Session timeout: if the client stops contacting the session for DebugSessionTimeoutSeconds, the game force-resumes the chip and closes the session.