Batch-insert notes into a MIDI item. Primary tool for writing MIDI.
AI agents use midi_insert_notes_batch to create or update resources in ReaperMCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your ReaperMCP environment.
This tool creates or modifies MIDI note data within a music production context. The operation is reversible (notes can be deleted or edited), and while it affects the project state, it does not irreversibly destroy data or execute arbitrary code. It fits the Write category as it generates or modifies structured musical data.
From the tool's definition Tool name contains 'insert' and description states 'Primary tool for writing MIDI' - directly modifies MIDI data by adding notes to a MIDI item.
Documented attack patterns abuse exactly the kind of access midi_insert_notes_batch gives an agent:
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 midi_insert_notes_batch:
{
"version": "1",
"default": "deny",
"tools": {
"midi_insert_notes_batch": {
"limits": [
{
"counter": "midi_insert_notes_batch_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}midi_insert_notes_batch 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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Batch-insert notes into a MIDI item. Primary tool for writing MIDI. 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.
Register the Reaper MCP server in PolicyLayer and add a rule for midi_insert_notes_batch: 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.
midi_insert_notes_batch 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 midi_insert_notes_batch 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 midi_insert_notes_batch. 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.
midi_insert_notes_batch 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.
Start from ReaperMCP, 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.
138 ReaperMCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.