deploy_function · Run402 MCP: Risk & Policy

WHAT IT DOES

What deploy_function does on Run402

AI agents invoke deploy_function to trigger actions in Run402. 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 deploy_function needs a policy

This tool allows execution of arbitrary code in a serverless environment. While not immediately destructive or financial, a malicious agent could use this to run malicious scripts, exfiltrate data, perform lateral movements, or disrupt services. The blast radius is significant because deployed functions execute in a production infrastructure context ('Autonomous infra for Coding Agents').

From the tool's definition Tool deploys and executes serverless functions (Node 22) with the ability to handle HTTP requests. The description states 'The function can' (incomplete, but implies execution capability).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

deploy_function Rate-limited

deploy_function 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": {
    "deploy_function": {
      "limits": [
        {
          "counter": "deploy_function_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 Run402, so you can run agents against it safely.

FAQ

Questions about deploy_function

What does the deploy_function tool do? +

Deploy a serverless function (Node 22) to a project. Handler signature: export default async (req: Request) => Response. The function can. It is categorised as a Execute tool in the Run402 MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on deploy_function? +

Register the Run402 MCP server in PolicyLayer and add a rule for deploy_function: 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 Run402. Nothing to install.

What risk level is deploy_function? +

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

Can I rate-limit deploy_function? +

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

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

deploy_function is provided by the Run402 MCP server (kychee-com/run402). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.