Set the volume of a track send.
AI agents use set_send_volume 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 creates or modifies audio mixer settings (send volume levels) within the DAW, which is a reversible change. The user can undo the action or adjust the send volume to a different value. It does not execute arbitrary code, delete data, or cause financial transactions. It falls clearly into the Write category as it modifies mixer state.
From the tool's definition Tool name is 'set_send_volume' and description states it will 'Set the volume of a track send.' This modifies audio routing parameters within REAPER DAW.
Documented attack patterns abuse exactly the kind of access set_send_volume 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 set_send_volume:
{
"version": "1",
"default": "deny",
"tools": {
"set_send_volume": {
"limits": [
{
"counter": "set_send_volume_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}set_send_volume 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.
Set the volume of a track send. 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 set_send_volume: 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.
set_send_volume 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 set_send_volume 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 set_send_volume. 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.
set_send_volume 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.