run_macro · Cnc Fluidnc MCP: Risk & Policy

WHAT IT DOES

What run_macro does on Cnc Fluidnc

AI agents invoke run_macro to trigger actions in Cnc Fluidnc. 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.

WHY IT NEEDS A POLICY

Why run_macro needs a policy

This tool executes arbitrary pre-defined code/sequences on CNC hardware, which falls under Execute category. Severity is high because misuse could cause: unintended machine movements, collision with workpieces/fixtures, tool damage, or operator injury.

From the tool's definition Tool description states 'Execute a saved macro' which performs a defined operation on CNC hardware. In context of a CNC router control server, macros are pre-programmed sequences that trigger physical machine movements and operations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

run_macro Rate-limited

run_macro 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "run_macro": {
      "limits": [
        {
          "counter": "run_macro_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Cnc Fluidnc, so you can run agents against it safely.

FAQ

Questions about run_macro

What does the run_macro tool do? +

Execute a saved macro. Shows preview first; set confirm=true to run. Parameters can override defaults. It is categorised as a Execute tool in the Cnc Fluidnc MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on run_macro? +

Register the Cnc Fluidnc MCP server in PolicyLayer and add a rule for run_macro: 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 Cnc Fluidnc. Nothing to install.

What risk level is run_macro? +

run_macro is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit run_macro? +

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

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

run_macro is provided by the Cnc Fluidnc MCP server (whitneydesignlabs/cnc-fluidnc-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.