add_midi_note

Instructions

Implementation Reference

• src/reaper_mcp/midi_tools.py:83-125 (handler)

  The add_midi_note tool handler function, decorated with @mcp.tool(). It adds a MIDI note to an existing MIDI item at a given track_index, item_index with specified pitch (0-127), start/length (seconds relative to item start), velocity, and channel. Uses reapy's take.add_note() under the hood.

  @mcp.tool()
  def add_midi_note(
      track_index: int,
      item_index: int,
      pitch: int,
      start: float,
      length: float,
      velocity: int = 100,
      channel: int = 0,
  ) -> dict:
      """
      Add a MIDI note to an existing MIDI item.
      pitch: MIDI note number 0–127 (60 = middle C, 69 = A4).
      start/length: seconds, relative to the item's start.
      channel: MIDI channel 0–15 (use 9 for drums).
      """
      try:
          project = get_project()
          track = project.tracks[track_index]
          item = track.items[item_index]
          take = item.active_take
          if not take.is_midi:
              return {"success": False, "error": "Item is not a MIDI item"}
          take.add_note(
              start=start,
              end=start + length,
              pitch=pitch,
              velocity=velocity,
              channel=channel,
          )
          return {
              "success": True,
              "track_index": track_index,
              "item_index": item_index,
              "pitch": pitch,
              "start": start,
              "length": length,
              "velocity": velocity,
              "channel": channel,
          }
      except Exception as e:
          logger.error(f"add_midi_note failed: {e}")
          return {"success": False, "error": str(e)}

• src/reaper_mcp/server.py:22-22 (registration)

  The registration call where register_tools from midi_tools is invoked with the mcp instance, which registers add_midi_note as an MCP tool.

  _reg_midi(mcp)

• src/reaper_mcp/server.py:12-12 (registration)

  Import of register_tools from midi_tools module into the server, aliased as _reg_midi.

  from reaper_mcp.midi_tools import register_tools as _reg_midi

• src/reaper_mcp/connection.py:7-27 (helper)

  The get_project helper function used by add_midi_note to obtain the current REAPER project via reapy.

  def ensure_connected() -> None:
      global _connected
      if _connected:
          return
      try:
          reapy.connect()
          _connected = True
          logger.info("Connected to REAPER")
      except Exception as e:
          raise RuntimeError(
              f"Cannot connect to REAPER: {e}. "
              "Make sure REAPER is running and the distant API is enabled. "
              "To enable it: run the setup script (scripts/enable_reapy.py) or "
              "in REAPER go to Actions > Run ReaScript, then run: "
              "import reapy; reapy.config.enable_dist_api()"
          ) from e
  
  
  def get_project() -> reapy.Project:

• src/reaper_mcp/midi_tools.py:84-92 (schema)

  The type-annotated function signature serves as the input schema for add_midi_note: track_index (int), item_index (int), pitch (int), start (float), length (float), velocity (int, default 100), channel (int, default 0).

  def add_midi_note(
      track_index: int,
      item_index: int,
      pitch: int,
      start: float,
      length: float,
      velocity: int = 100,
      channel: int = 0,
  ) -> dict: