Factorio MCP Bridge

M0 is a working, tested integration checkpoint for Factorio 2.0.77 on Windows. A Lua mod answers bounded JSON commands over loopback RCON; one shared TypeScript daemon serves MCP clients over stdio and authenticated Streamable HTTP.

The bounded M1 read-only checkpoint now passes live spatial, inventory, diagnostic, cache, isolation, and reload acceptance tests. Broader specification features remain deferred. See the M1 checkpoint guide. Gameplay mutations, plans, construction, and jobs remain unavailable.

Reproduce the checkpoint

Use Node 24.19.0 and Python 3.11+. In PowerShell:

npm ci
python -m venv .venv
.venv/Scripts/python.exe -m pip install -r requirements-test.txt
npm run checkpoint:m0

The live runner defaults to C:/Steam/steamapps/common/Factorio/bin/x64/Factorio.exe. Set FACTORIO_EXECUTABLE and optionally FACTORIO_RUNTIME_API for another installation. It requires matching 2.0.77 runtime documentation.

Every run creates a new .fmcp/live/<run>/ directory with separate game configuration, mods, and saves. It disables public/LAN discovery, binds game/RCON/daemon sockets to loopback, and stops its processes on completion. It never installs into your normal mod directory or opens an existing user save. Temporary test credentials stay in ignored local files; do not publish .fmcp/.

dev:world prints a ready-to-copy stdio command with an explicit local configuration path. Keep that terminal open; press Ctrl+C to stop the test world and daemon. Do not run two checkpoint processes concurrently because they both update the latest report.

Outputs are dist/cli.js, dist/factorio-mcp-bridge_0.2.1.zip, and the unpacked mod under dist/mod/. The CLI bundles all non-Node runtime dependencies. Mod ZIP entries have fixed ordering and timestamps. Live reports are written to artifacts/live-latest.json and the individual run directory.

Related MCP server: godot-mcp-rts

Read next

• Checkpoint guide: test layers, manual app scenario, and milestone gates.

• Compatibility and recorded versions: exact tested lanes and limits.

• Limitations: what this checkpoint does and does not implement.

• Client templates: the same bundled CLI for each client.

• Development installation: source-linked MCP and skill setup for Codex.

• Specification: architecture and milestone contract.

• Progress: completed work, actual commands, and next milestone.

The seven canonical tool definitions remain stable in the tool schema catalog. Effective discovery includes the tested integration, recipe, research, and production paths when an operator policy is configured. The bounded spatial, inventory, resource, artifact, and observation operations are now tested and advertised. Deferred tools return CAPABILITY_UNAVAILABLE, never simulated factory results.

The operator skill and workflow examples describe later operation flows as well; discover effective capabilities before using them. The original handoff validation describes static specification fixtures, while checkpoint test status records the implemented M0 lane.

Version 0.2.1 adds bounded, scoped event history through query.events; see the event contract.