vibekit_start_app · Vibekit MCP: Risk & Policy

WHAT IT DOES

What vibekit_start_app does on Vibekit

AI agents invoke vibekit_start_app to trigger actions in Vibekit. 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 vibekit_start_app needs a policy

This tool executes an action that brings a deployed application online, which could have unintended consequences depending on the app's configuration, permissions, and what it does when started. While not destructive (the app can be stopped again), it performs an irreversible operational change in a hosted environment.

From the tool's definition The tool 'vibekit_start_app' starts a stopped hosted app. Starting/stopping applications represents execution of operations that trigger external state changes in hosted infrastructure.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

vibekit_start_app Rate-limited

vibekit_start_app 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": {
    "vibekit_start_app": {
      "limits": [
        {
          "counter": "vibekit_start_app_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 Vibekit, so you can run agents against it safely.

FAQ

Questions about vibekit_start_app

What does the vibekit_start_app tool do? +

Start a stopped hosted app. It is categorised as a Execute tool in the Vibekit MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on vibekit_start_app? +

Register the Vibekit MCP server in PolicyLayer and add a rule for vibekit_start_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 Vibekit. Nothing to install.

What risk level is vibekit_start_app? +

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

Can I rate-limit vibekit_start_app? +

Yes. Add a rate_limit block to the vibekit_start_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 vibekit_start_app completely? +

Set action: deny in the PolicyLayer policy for vibekit_start_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 vibekit_start_app? +

vibekit_start_app is provided by the Vibekit MCP server (vibekit-apps/vibekit-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.