fork_app · Run402 MCP: Risk & Policy

WHAT IT DOES

What fork_app does on Run402

AI agents use fork_app to create or update resources in Run402 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Run402 environment.

WHY IT NEEDS A POLICY

Why fork_app needs a policy

This tool creates a new project with a full copy of an existing app's database, functions, and site. It is a Write operation (creating new resources) rather than Destructive since it doesn't delete the original.

From the tool's definition Fork a published app into a new project. Creates a full copy including database, functions, site, and optionally claims a subdomain.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

fork_app Rate-limited

fork_app stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "fork_app": {
      "limits": [
        {
          "counter": "fork_app_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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 fork_app

What does the fork_app tool do? +

Fork a published app into a new project. Creates a full copy including database, functions, site, and optionally claims a subdomain. It is categorised as a Write tool in the Run402 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on fork_app? +

Register the Run402 MCP server in PolicyLayer and add a rule for fork_app: 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 fork_app? +

fork_app is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit fork_app? +

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

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

fork_app 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.