set_fx_parameter
Adjust any FX plugin parameter by setting a normalized value between 0.0 and 1.0. Use parameter indices obtained from get_fx_parameters to target specific parameters.
Instructions
Set a normalized parameter value (0.0–1.0) on an FX plugin. Use get_fx_parameters to discover available parameters and their indices.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| track_index | Yes | ||
| fx_index | Yes | ||
| param_index | Yes | ||
| value | Yes |
Implementation Reference
- src/reaper_mcp/fx_tools.py:51-74 (handler)The handler function for the set_fx_parameter tool. Decorated with @mcp.tool(), it sets a normalized parameter value (0.0–1.0) on an FX plugin at the given track/fx/param indices.
@mcp.tool() def set_fx_parameter( track_index: int, fx_index: int, param_index: int, value: float ) -> dict: """ Set a normalized parameter value (0.0–1.0) on an FX plugin. Use get_fx_parameters to discover available parameters and their indices. """ try: project = get_project() track = project.tracks[track_index] fx = track.fxs[fx_index] fx.params[param_index].normalized_value = value param_name = fx.params[param_index].name return { "success": True, "track_index": track_index, "fx_index": fx_index, "param_index": param_index, "param_name": param_name, "value": value, } except Exception as e: return {"success": False, "error": str(e)} - src/reaper_mcp/fx_tools.py:52-54 (schema)Type-annotated input schema for set_fx_parameter: track_index (int), fx_index (int), param_index (int), value (float). Return type is dict.
def set_fx_parameter( track_index: int, fx_index: int, param_index: int, value: float ) -> dict: - src/reaper_mcp/server.py:13-21 (registration)The tool is registered in server.py by importing register_tools from fx_tools.py and calling it with the mcp instance. Inside fx_tools.py, the @mcp.tool() decorator on set_fx_parameter registers it.
from reaper_mcp.fx_tools import register_tools as _reg_fx from reaper_mcp.audio_tools import register_tools as _reg_audio from reaper_mcp.mixing_tools import register_tools as _reg_mixing from reaper_mcp.render_tools import register_tools as _reg_render from reaper_mcp.mastering_tools import register_tools as _reg_mastering from reaper_mcp.analysis_tools import register_tools as _reg_analysis _reg_project(mcp) _reg_track(mcp) - src/reaper_mcp/connection.py:27-29 (helper)Helper function used by set_fx_parameter to obtain the current REAPER project via reapy.
def get_project() -> reapy.Project: ensure_connected() return reapy.Project()