unlock_machine · Cnc Fluidnc MCP: Risk & Policy

WHAT IT DOES

What unlock_machine does on Cnc Fluidnc

AI agents invoke unlock_machine 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 unlock_machine needs a policy

Unlocking a CNC machine clears a safety alarm state and re-enables machine motion. This is an external operation that triggers physical machinery to become operational again.

From the tool's definition 'Clear alarm state and unlock the machine ($X). Use after an alarm condition.'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

unlock_machine Rate-limited

unlock_machine 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": {
    "unlock_machine": {
      "limits": [
        {
          "counter": "unlock_machine_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 unlock_machine

What does the unlock_machine tool do? +

Clear alarm state and unlock the machine ($X). Use after an alarm condition. 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 unlock_machine? +

Register the Cnc Fluidnc MCP server in PolicyLayer and add a rule for unlock_machine: 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 unlock_machine? +

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

Can I rate-limit unlock_machine? +

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

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

unlock_machine 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.