fx_remove

THE RISK

Critical Risk

Why fx_remove needs a policy

Removing an FX plugin from a track chain deletes it along with all its parameter settings and potentially automation data. While REAPER has undo history within a session, MCP tool invocations by an AI agent may bypass or exhaust undo stacks, and the action is inherently destructive in nature. The blast radius is high because misuse could silently strip carefully configured effects chains from tracks in a project.

From the tool's definition 'Remove FX from track chain' — removing an effect from a track chain is an irreversible destructive action that permanently deletes the FX slot, including any settings/automation configured for it.

Documented attack patterns abuse exactly the kind of access fx_remove gives an agent:

POLICY

How to control fx_remove

PolicyLayer is an MCP gateway — it sits between your AI agents and ReaperMCP, and nothing reaches the server without passing your rules. This is the rule we recommend for fx_remove:

policy.json

{
  "version": "1",
  "default": "deny",
  "hide": [
    "fx_remove"
  ]
}

fx_remove disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.

Create a free account and register ReaperMCP — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RESTRICT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

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All 138 ReaperMCP tools →

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Go deeper

Critical-risk tools in ReaperMCP → Every critical-risk tool this server exposes, in one view.
All critical-risk MCP tools → Every critical-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Blast radius → How much damage one compromised or confused agent can do — and how to bound it.
Tool call approval → Approval gates on individual tool calls: auto-allow, prompt, or deny.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about fx_remove

What does the fx_remove tool do? +

Remove FX from track chain. It is categorised as a Destructive tool in the ReaperMCP MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.

How do I enforce a policy on fx_remove? +

Register the Reaper MCP server in PolicyLayer and add a rule for fx_remove: 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 ReaperMCP. Nothing to install.

What risk level is fx_remove? +

fx_remove is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit fx_remove? +

Yes. Add a rate_limit block to the fx_remove 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.

How do I block fx_remove completely? +

Set action: deny in the PolicyLayer policy for fx_remove. 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.

What MCP server provides fx_remove? +

fx_remove is provided by the Reaper MCP server (xdarkzx/reaper-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every ReaperMCP tool call.

Start from ReaperMCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →