execute_code · Fastmcp Gateway MCP: Risk & Policy

WHAT IT DOES

What execute_code does on Fastmcp Gateway

AI agents invoke execute_code to trigger actions in Fastmcp Gateway. 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 execute_code needs a policy

Code execution tools are inherently Execute category and pose critical risk. An LLM agent using this without proper safeguards could execute malicious, unintended, or destructive code. The empty description increases uncertainty slightly but the explicit 'execute_code' name is definitive evidence of Execute semantics.

From the tool's definition Tool name is 'execute_code' with no description provided. The name directly indicates code execution capability.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

execute_code Rate-limited

execute_code 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": {
    "execute_code": {
      "limits": [
        {
          "counter": "execute_code_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 Fastmcp Gateway, so you can run agents against it safely.

FAQ

Questions about execute_code

What does the execute_code tool do? +

execute_code. It is categorised as a Execute tool in the Fastmcp Gateway MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on execute_code? +

Register the Fastmcp Gateway MCP server in PolicyLayer and add a rule for execute_code: 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 Fastmcp Gateway. Nothing to install.

What risk level is execute_code? +

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

Can I rate-limit execute_code? +

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

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

execute_code is provided by the Fastmcp Gateway MCP server (ultrathink-solutions/fastmcp-gateway). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.