transport_set_playrate

THE RISK

Medium Risk

Why transport_set_playrate needs a policy

This tool modifies the transport playback rate in REAPER, which is a reversible state change (it can be set back to normal). It does not execute code, delete data, or involve finances. It writes/updates a configuration parameter of the playback engine.

From the tool's definition Set playback speed

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

POLICY

How to control transport_set_playrate

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 transport_set_playrate:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "transport_set_playrate": {
      "limits": [
        {
          "counter": "transport_set_playrate_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

transport_set_playrate 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.

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.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More ReaperMCP tools

Destructive envelope_clear_range envelope_clear_range Destructive fx_remove Remove FX from track chain. Destructive item_delete Delete an item. Destructive marker_delete Delete marker/region. Destructive midi_delete_all_notes Clear all notes from a MIDI item. Destructive midi_delete_cc Delete a CC event. Destructive midi_delete_note Delete a note. Destructive tempo_clear_all Delete every tempo/time-sig marker — resets the project to its base tempo.

All 138 ReaperMCP tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about transport_set_playrate

What does the transport_set_playrate tool do? +

Set playback speed. It is categorised as a Write tool in the ReaperMCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on transport_set_playrate? +

Register the Reaper MCP server in PolicyLayer and add a rule for transport_set_playrate: 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 transport_set_playrate? +

transport_set_playrate is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit transport_set_playrate? +

Yes. Add a rate_limit block to the transport_set_playrate 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 transport_set_playrate completely? +

Set action: deny in the PolicyLayer policy for transport_set_playrate. 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 transport_set_playrate? +

transport_set_playrate 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 →