AI agents use add_compressor 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 a new effect plugin on a track, modifying the track's signal chain reversibly. It is Write-category because it adds/modifies track state without irreversible deletion or financial impact. Severity is medium because misuse could degrade audio quality or corrupt a project, but changes are reversible via undo.
From the tool's definition Tool name 'add_compressor' and description 'Add ReaComp to a track' indicate creation/modification of track configuration by inserting an audio effect.
Documented attack patterns abuse exactly the kind of access add_compressor 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 add_compressor:
{
"version": "1",
"default": "deny",
"tools": {
"add_compressor": {
"limits": [
{
"counter": "add_compressor_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}add_compressor 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.
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Add ReaComp to a track. 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 add_compressor: 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.
add_compressor 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 add_compressor 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 add_compressor. 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.
add_compressor 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.
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158 Reaper tools catalogued and risk-classified — across an index of 43,000+ MCP servers.