mcp-strudel - Strudel ↔ MIDI MCP server

An MCP server that exposes the Strudel mini-notation engine (shared with the m4l-strudel device) as tools Claude can call. Combine it with ableton-mcp so you can say things like "lay down a bd(3,8) kick and a c5 [e5 g5]*2 bassline" and have Claude convert the patterns and write them into Ableton clips.

Tools

Tool	Input	Output
strudel_to_midi	pattern, bars, cycles, conv, octaveOffset, velocity	JSON note events (pitch, start, duration in beats) + lengthBeats
midi_to_strudel	notes[], bars, grid, conv, octaveOffset	mini-notation text
strudel_validate	pattern	parse errors or "OK"

conv = strudel (c5=60, default) or scientific (c4=60).

Run

pnpm install
pnpm test # engine contract tests (vitest)
pnpm start # launches the stdio MCP server (tsx src/server.ts)

Wire it into Claude

Add to the MCP config you pass to the Claude Code CLI (e.g. the mcp-config.json that the m4l-claude device generates), alongside AbletonMCP:

{
 "mcpServers": {
 "AbletonMCP": { "command": "uvx", "args": ["ableton-mcp"] },
 "strudel": {
 "command": "npx",
 "args": ["-y", "tsx", "C:/Users/jaime/src/livecam-m4l/tmp/mcp-strudel/src/server.ts"]
 }
 }
}

With both servers available, Claude can call strudel_to_midi to turn a pattern into notes, then use AbletonMCP's clip/note tools to create the clip - the m4l-strudel → mcp-strudel → ableton-mcp path, orchestrated in natural language.

Engine

src/lib/mini/ is the same parser/scheduler/unparser as the m4l-strudel device (recursive-descent parser, Bjorklund euclidean rhythms, cycle scheduler, grid quantizer). Keeping one engine means the device and the server always agree on how a pattern sounds.