Ableton Live MCP

An MCP server for Ableton Live 12, built on the official Ableton Extensions SDK. The MCP server runs inside Live as an extension — no bridge process, no MIDI remote scripts. Any MCP client (Claude Code, Claude Desktop, Cursor, ...) connects over streamable HTTP and gets full programmatic control of the Live Set: tracks, clips, MIDI notes, devices, parameters, mixer, scenes, warping, rendering, and more.

MCP client (Claude, ...) ──streamable HTTP──▶ http://127.0.0.1:8722/mcp
                                                      │
                                     Live Extension Host (Node.js)
                                                      │
                                              Ableton Live 12

Requirements

• Ableton Live 12.4.5 or newer (Extensions support)
• Node.js >= 24.14 (build only)

Install

npm install
npm run package        # builds and produces Ableton-Live-MCP-<version>.ablx

Then drag the .ablx file onto Settings → Extensions in Live. The MCP endpoint starts with Live at http://127.0.0.1:8722/mcp (GET /health for a quick check).

Development mode

Enable Settings → Extensions → Developer Mode in Live, then:

npm start              # builds and runs the extension against the running Live

.env must point at your Live installation, e.g. EXTENSION_HOST_PATH=/Applications/Ableton Live 12 Beta.app.

Connect a client

Claude Code:

claude mcp add --transport http ableton-live http://127.0.0.1:8722/mcp

Claude Desktop (or any stdio-only client) via mcp-remote:

{
  "mcpServers": {
    "ableton-live": {
      "command": "npx",
      "args": ["mcp-remote", "http://127.0.0.1:8722/mcp"]
    }
  }
}

Configuration

The port is stored in config.json inside the extension's storage directory (created on first run; the path is reported by song_get under environment.storage_directory). Default:

{ "port": 8722 }

How it works

• Every Live object (track, clip, device, parameter, ...) is addressed by a stable object id discovered through listing tools (song_get, track_get, device_get, ...).
• Ids stay valid until the object is deleted or moved, or another Live Set is loaded. Stale ids return an error telling the client to re-list.
• All times/positions are in beats; colors are #RRGGBB; MIDI pitches are 0–127.
• Multi-value writes (parameter_set) are grouped into a single undo step in Live.

Tools

Song

Tool	Description
song_get	Live Set state: tempo, scale, grid, tracks, return/main tracks, scenes, cue points, environment info. The entry point — returns the object ids used everywhere else. include fetches only selected sections.
song_set	Set song properties (tempo).

Tracks

Tool	Description
track_get	Track detail: clip slots + clips, take lanes, arrangement clips, devices, mixer with values. Address by track_id, track_index, or track_name; include selects sections.
track_set	Name / mute / solo / arm.
track_create	New audio or MIDI track.
track_delete	Delete track.
track_duplicate	Duplicate track.
track_clear_clips_in_range	Delete/truncate arrangement clips in a beat range.
take_lane_create	Add a take lane to a track.
take_lane_set	Rename a take lane.

Scenes & cue points

Tool	Description
scene_create / scene_set / scene_delete / scene_duplicate	Manage scenes.
cue_point_create / cue_point_set / cue_point_delete	Manage arrangement locators.

Clips

Tool	Description
clip_create	Create MIDI or audio clips in a session slot (by id or track + scene_index), arrangement track, or take lane. MIDI clips take inline notes; name/color apply at creation. Audio files are imported into the project automatically.
clip_get	Full clip detail (audio: warp settings + markers; MIDI: note count).
clip_set	Name, color, mute, looping, warping, warp mode.
clip_delete	Delete a session or arrangement clip.
midi_clip_get_notes	Read all MIDI notes.
midi_clip_set_notes	Write notes: replace all or merge (layer on top).
midi_clip_edit_notes	Server-side note transforms — transpose, time-shift, velocity scale/offset, quantize, delete — with pitch/time selection. No read-modify-write roundtrip.

Devices & racks

Tool	Description
device_get	Device detail: parameters with ranges/value items (parameter_filter substring, include_values, include_value_items), rack chains (include_chain_devices inlines pad devices), Simpler sample.
device_insert	Insert a built-in Live device into a track or rack chain.
device_delete / device_duplicate	Remove or copy devices.
chain_get	Rack chain detail: devices + chain mixer.
rack_insert_chain	Add a chain to a rack.
drum_chain_set	Set the MIDI note of a drum rack pad.
simpler_replace_sample	Swap the sample in a Simpler.

Parameters & mixing

Tool	Description
parameter_get	Read device/mixer parameter values (batch).
parameter_set	Write parameter values (batch, single undo step).
mixer_get	Volume / pan / sends of a track or chain, with parameter ids and unit hints.
mixer_set	Set volume / pan / sends of a track or chain in one call (single undo step).

Files & rendering

Tool	Description
import_file	Copy a file into the Live project.
render_track_audio	Render pre-FX audio of an audio track to a WAV.

UI & commands

Tool	Description
show_dialog	Show a modal HTML dialog inside Live (ask the user, show reports).
execute_command	Invoke Extension Host commands, e.g. ableton-live-mcp.status.

Skills

skills/ableton-live/SKILL.md is an installable agent skill that teaches an MCP client how to use these tools well (id discovery flow, beats vs. seconds, note-editing patterns, device workflows). Install it for Claude Code with:

mkdir -p ~/.claude/skills && cp -r skills/ableton-live ~/.claude/skills/

Typical things you can ask a connected assistant to do:

• "Create a 4-bar house drum pattern on a new MIDI track with a Drum Rack"
• "Warp all clips on the Drums track in Complex Pro mode"
• "Turn down every track that isn't the vocal bus by 3 dB"
• "Build a song skeleton: intro, verse, chorus scenes with locators"
• "Replace the sample in Simpler with /path/to/kick.wav and map it to C1"

Limitations

• The extension (and thus the MCP endpoint) only runs while Live is open.
• Only built-in Live devices can be inserted; third-party plug-ins can't be loaded by the SDK.
• No transport control (play/stop/record) or clip launching — the Extensions API v1.0.0 does not expose them. Same for browser access and parameter automation curves.
• show_dialog blocks until the user closes the dialog in Live.

Tests

npm test                  # E2E against a mock Extension Host: MCP client ↔ HTTP ↔ all tools
node test/live-smoke.mjs  # against a real running Live with the extension loaded

The live smoke test creates its own tracks/clips/devices, verifies every tool family (MIDI notes, warping, drum racks, rendering, ...), and deletes everything it created.

Extension Host quirks (worth knowing)

Two behaviors of the beta Extension Host that this project works around:

1. Bare VM context. Extensions are evaluated in a V8 context without global or web globals (Request, Response, ReadableStream, fetch, EventTarget, ...), which the MCP SDK needs at load time. build.ts injects a banner that pulls them in from the main Node context (core-module functions are shared, so their Function constructor evaluates there). See build.ts for details.
2. bigint numerics. The host returns bigint for some values the SDK types as number (clip colors, note pitches, ...). src/serialize.ts normalizes with num() before arithmetic/JSON.
3. Asynchronous writes. SDK property setters (notes, names, values) return before Live has applied the change; a read within a few tens of ms can return the previous state. Agents rarely notice, but read-after-write tests must retry briefly (see eventually() in test/live-smoke.mjs).

Also: if the dev Extension Host crashes, Live may refuse the next control-channel handshake ("bring-up timed out") — restart Live and run npm start again.

Troubleshooting

• Endpoint not responding: check curl http://127.0.0.1:8722/health. Right-click any track in Live — the "Ableton Live MCP: Status" context-menu action shows the endpoint the extension actually bound.
• Port already in use: if another process holds the configured port, the server logs the failure to ExtensionHost.txt and does not start. Change port in the extension's config.json (path shown by song_get under environment.storage_directory) — the file is read once at startup, so restart Live afterwards.
• Changed config.json but nothing happened: config is only read when the extension starts. Restart Live (or the dev Extension Host).

License

MIT for the code in this repository. The vendor/ tarballs (Ableton Extensions SDK & CLI) are Ableton's and covered by their own license (see sdk/LICENSE.md in the SDK distribution).