AbletonMCP

Instructions

Implementation Reference

• MCP_Server/server.py:322-342 (handler)

  Primary MCP tool handler for 'create_clip'. Decorated with @mcp.tool() for automatic registration and schema inference from signature/docstring. Proxies parameters to the Ableton remote script via socket command.

  @mcp.tool()
  def create_clip(ctx: Context, track_index: int, clip_index: int, length: float = 4.0) -> str:
      """
      Create a new MIDI clip in the specified track and clip slot.
      
      Parameters:
      - track_index: The index of the track to create the clip in
      - clip_index: The index of the clip slot to create the clip in
      - length: The length of the clip in beats (default: 4.0)
      """
      try:
          ableton = get_ableton_connection()
          result = ableton.send_command("create_clip", {
              "track_index": track_index, 
              "clip_index": clip_index, 
              "length": length
          })
          return f"Created new clip at track {track_index}, slot {clip_index} with length {length} beats"
      except Exception as e:
          logger.error(f"Error creating clip: {str(e)}")
          return f"Error creating clip: {str(e)}"

• AbletonMCP_Remote_Script/__init__.py:455-482 (handler)

  Core implementation of clip creation using Ableton Live API: retrieves track and clip_slot then calls clip_slot.create_clip(length). Called by the remote script's command dispatcher.

  def _create_clip(self, track_index, clip_index, length):
      """Create a new MIDI clip in the specified track and clip slot"""
      try:
          if track_index < 0 or track_index >= len(self._song.tracks):
              raise IndexError("Track index out of range")
          
          track = self._song.tracks[track_index]
          
          if clip_index < 0 or clip_index >= len(track.clip_slots):
              raise IndexError("Clip index out of range")
          
          clip_slot = track.clip_slots[clip_index]
          
          # Check if the clip slot already has a clip
          if clip_slot.has_clip:
              raise Exception("Clip slot already has a clip")
          
          # Create the clip
          clip_slot.create_clip(length)
          
          result = {
              "name": clip_slot.clip.name,
              "length": clip_slot.clip.length
          }
          return result
      except Exception as e:
          self.log_message("Error creating clip: " + str(e))
          raise

• AbletonMCP_Remote_Script/__init__.py:247-251 (registration)

  Command registration/dispatch in the Ableton remote script's socket command processor (_process_command). Routes 'create_clip' to the _create_clip handler.

  elif command_type == "create_clip":
      track_index = params.get("track_index", 0)
      clip_index = params.get("clip_index", 0)
      length = params.get("length", 4.0)
      result = self._create_clip(track_index, clip_index, length)

• MCP_Server/server.py:324-331 (schema)

  Tool schema defined by function parameters and docstring, used by FastMCP for input validation and tool description.

  """
  Create a new MIDI clip in the specified track and clip slot.
  
  Parameters:
  - track_index: The index of the track to create the clip in
  - clip_index: The index of the clip slot to create the clip in
  - length: The length of the clip in beats (default: 4.0)
  """

• MCP_Server/server.py:104-109 (helper)

  List classifying 'create_clip' as a state-modifying command, which receives special handling (delays, timeouts) in the socket send_command method.

  is_modifying_command = command_type in [
      "create_midi_track", "create_audio_track", "set_track_name",
      "create_clip", "add_notes_to_clip", "set_clip_name",
      "set_tempo", "fire_clip", "stop_clip", "set_device_parameter",
      "start_playback", "stop_playback", "load_instrument_or_effect"
  ]