MCP Overview - Vibrai

The Vibrai MCP server gives an AI assistant direct, bidirectional control over Ableton Live. You describe what you want in plain language — “create a four-bar bass loop in D minor” or “build a minimal techno track with three sections” — and the assistant calls the right sequence of tools while you watch the results appear in Live.

How the connection works

The core request path is a three-layer stack:

vibrai.amxd — a Max for Live device you load on any track. Inside it, a Node.js script runs an Express HTTP server on localhost:3333 and translates REST calls into Live’s LOM via the Max js object.
Vibrai.Mcp — a C# process that communicates with your MCP client over stdio using JSON-RPC. Every tool call is proxied to the M4L device via HTTP.
Your MCP client — Claude Desktop, Claude Code, Cursor, or any other MCP-capable host. It sees the tools via the standard tools/list / tools/call protocol.

The M4L device is stateless. All Vibrai-specific state — project files, instrument tags, genre libraries — lives on disk alongside your Live set and is managed by the C# layer. Session-view automation (envelope reads and writes) additionally routes through the Vibrai Python remote script on localhost:3334, installed separately via install_vibrai_remote_script / vibrai install remote-script. get_version reports it as the python_bridge field. See Installation and Troubleshooting.

Connecting Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "vibrai": {
      "command": "/usr/local/lib/vibrai/Vibrai.Mcp",
      "env": {
        "VIBRAI_LOG_FILE": "/tmp/vibrai-mcp.log",
        "VIBRAI_LOG_LEVEL": "Warning"
      }
    }
  }
}

Restart Claude Desktop. Open a new conversation — the Vibrai tools will be available.

How tools map to engine operations

Each MCP tool corresponds directly to a method on the underlying engine or bridge. Tools are grouped by domain: transport, tracks, clips, notes, drum maps, automation, devices, instruments, scenes, arrangement, scales, project, genre, generation, capture, sessions, license, install, update, uninstall, and version. See the Reference section for every tool, its parameters, and the matching CLI command.

snake_case parameter convention

All MCP tool parameters use snake_case. This is enforced at the wire level:

track_id, scene_index, start_beat, source_scene_index, part_type

If an LLM sends camelCase keys (for example trackId instead of track_id), the server’s binding filter catches the failure and returns a clear error message pointing at the correct snake_case form.

First-song wizard

The fastest way to hear Vibrai in action through MCP is the first-song wizard:

Build a lofi-house song, medium length.

The assistant calls start_first_song(vibe="lofi-house", length="medium"), which returns a step-by-step recipe. It then executes the recipe: Claude assembles a complete project and saves it, then loads instruments, generates the parts, and starts playback. A full arrangement appears in Live in about 30–60 seconds. Supported vibes: ambient-techno (default), lofi-house, deep-house, ambient-downtempo, minimal-techno.

Reference pages

The full parameter schema for every tool lives in the generated Reference section:

​How the connection works

​Connecting Claude Desktop

​How tools map to engine operations

​snake_case parameter convention

​First-song wizard

​Reference pages