Send a single G-code or Grbl command to the CNC machine. Safety level is auto-classified. DANGEROUS/CRITICAL commands require confirm=true.
AI agents invoke send_gcode 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.
This tool sends G-code or Grbl commands directly to a CNC router, triggering real-world physical motion and operations. Misuse could cause the machine to crash into fixtures, break tooling, injure operators, or destroy workpieces. The description itself flags some commands as DANGEROUS/CRITICAL, confirming high blast radius.
From the tool's definition 'Send a single G-code or Grbl command to the CNC machine' and 'DANGEROUS/CRITICAL commands require confirm=true' — executes arbitrary machine control commands on physical CNC hardware
Attacks that exploit this kind of access
Send a single G-code or Grbl command to the CNC machine. Safety level is auto-classified. DANGEROUS/CRITICAL commands require confirm=true. 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.
Register the Cnc Fluidnc MCP server in PolicyLayer and add a rule for send_gcode: 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.
send_gcode is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the send_gcode 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 send_gcode. 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.
send_gcode 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.
send_gcode is one line of Cnc Fluidnc's registry record.
The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.
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