ReaMCP

Instructions

Implementation Reference

• src/reaper_mcp/server.py:561-577 (handler)

  The MCP tool handler for set_fx_preset in server.py, which wraps the adapter call.

  def set_fx_preset(track_index: int, fx_index: int, preset_name: str) -> dict[str, Any]:
      """
      Load a named preset for an FX plugin on a track.
      preset_name can be:
      - A plain preset name or index-based name (for plugins with internal preset banks)
      - A full absolute file path to a .ffp/.fxp/.fxb file (FabFilter and others).
        Use the 'path' field from list_fx_presets() for file-based plugins.
      On failure, returns loaded=false with a failure_reason:
        'preset_name_not_found'   - name not in the plugin's preset list
        'plugin_rejected_state'   - plugin returned false despite the name existing
        'plugin_has_no_presets'   - plugin exposes no preset bank at all
        'file_unreadable'         - path given but file could not be opened
      """
      try:
          return _wrap(
              adapter.set_fx_preset(
                  track_index=track_index, fx_index=fx_index, preset_name=preset_name

• src/reaper_mcp/reaper_adapter.py:320-328 (handler)

  The adapter method that forwards the set_fx_preset request to the underlying Reaper client.

  def set_fx_preset(
      self, track_index: int, fx_index: int, preset_name: str
  ) -> dict[str, Any]:
      return self._client.call(
          "set_fx_preset",
          track_index=track_index,
          fx_index=fx_index,
          preset_name=preset_name,
      )