Move an FX plugin to a new position within the same track's FX chain.
AI agents use track_fx_move to create or update resources in Reaper — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Reaper environment.
This tool modifies the arrangement of effects in a track's processing chain, which is a Write operation: it changes project state reversibly and persistently. While it doesn't delete or irreversibly destroy data (Destructive), it goes beyond mere querying (Read) and doesn't execute arbitrary code or shell commands (Execute).
From the tool's definition Tool description states 'Move an FX plugin to a new position within the same track's FX chain' — this modifies the order/configuration of audio processing effects on a track, which is a reversible state change to the REAPER DAW project.
Documented attack patterns abuse exactly the kind of access track_fx_move gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Reaper, and nothing reaches the server without passing your rules. This is the rule we recommend for track_fx_move:
{
"version": "1",
"default": "deny",
"tools": {
"track_fx_move": {
"limits": [
{
"counter": "track_fx_move_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}track_fx_move stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Move an FX plugin to a new position within the same track's FX chain. It is categorised as a Write tool in the Reaper MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Reaper MCP server in PolicyLayer and add a rule for track_fx_move: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Reaper. Nothing to install.
track_fx_move is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the track_fx_move rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for track_fx_move. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
track_fx_move is provided by the Reaper MCP server (twelvetake-studios/reaper-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Reaper, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
158 Reaper tools catalogued and risk-classified — across an index of 43,000+ MCP servers.