Move the edit cursor to a region start.
AI agents invoke go_to_region to trigger actions in Reaper. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
While moving a cursor is reversible and non-destructive, it is an Execute action because it triggers an external operation with effects that depend on arguments (which region is targeted). It modifies the application state in a way that could affect subsequent operations. It does not merely read data (Read), create/modify data reversibly in a structured way (Write), or delete anything (Destructive).
From the tool's definition Tool performs an action ('Move the edit cursor to a region start') that triggers an external operation in REAPER DAW. This is a state-changing operation on the DAW that alters the current playhead/cursor position, which affects the editing workflow.
Documented attack patterns abuse exactly the kind of access go_to_region 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 go_to_region:
{
"version": "1",
"default": "deny",
"tools": {
"go_to_region": {
"limits": [
{
"counter": "go_to_region_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}go_to_region stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Move the edit cursor to a region start. It is categorised as a Execute tool in the Reaper MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Reaper MCP server in PolicyLayer and add a rule for go_to_region: 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.
go_to_region is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the go_to_region 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 go_to_region. 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.
go_to_region 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.