plainsong-mcp

# plainsong-mcp <p align="center"> <img src="assets/images/hero.jpg" alt="Agents composing — the MCP seam between notation and sound" width="640"> </p> A Model Context Protocol server for [Plainsong](https://github.com/SuperInstance/plainsong), so any agent can read, write and compile music notation — and so several agents can work on one score at the same time without overwriting each other. ```bash plainsong-mcp # JSON-RPC over stdio, what most clients expect plainsong-mcp --http # loopback HTTP, for remote and multi-agent setups plainsong-mcp --list-tools # what it exposes ``` ## Install ```bash pip install git+https://github.com/SuperInstance/plainsong-mcp ``` That brings in the compiler as well. Neither has any other dependency: the protocol, both transports, the session store and the compiler itself are written against the standard library. Python 3.10 or newer. The compiler comes from PyPI as `plainsong>=1.4.0`. 1.1.0 is the first release carrying `plainsong.features`, the per-bar analysis this package re-exports rather than duplicating; 1.4.0 is the first carrying `plainsong.runtime.localhost`, the loopback check behind the same re-export, so 1.4.0 is now the binding floor. Either way the requirement is real: below it the install succeeds and the import fails. ## Point a client at it For a client that launches servers over stdio, the usual shape is: ```json { "mcpServers": { "plainsong": { "command": "plainsong-mcp" } } } ``` Then ask it for music. The server exposes 27 tools, which is everything the `plainsong` CLI can do — write and validate notation, compile to MIDI and audio, transpose, search a library of several thousand pieces, analyse what each listener on a stage actually hears, and probe what the host machine can render. ## Many agents, one score The reason this exists. A session gives every agent a voice of its own: ``` ensemble_open name a session, set key, tempo and metre ensemble…