transport_stop · Flai MCP: Risk & Policy

WHAT IT DOES

What transport_stop does on Flai

AI agents invoke transport_stop to trigger actions in Flai. 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 transport_stop needs a policy

This tool executes a command that controls FL Studio's transport mechanism, causing an immediate state change in the music production software. While not destructive (no data loss) or financial, it falls into Execute category because it triggers an external operation whose effect (stopping playback) is a real-world action.

From the tool's definition Tool directly triggers playback stop action in FL Studio via Virtual MIDI control. Description states 'Stop playback' which is an external operation with effects dependent on system state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

transport_stop Rate-limited

transport_stop 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": {
    "transport_stop": {
      "limits": [
        {
          "counter": "transport_stop_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 Flai, so you can run agents against it safely.

FAQ

Questions about transport_stop

What does the transport_stop tool do? +

Stop playback in FL Studio. It is categorised as a Execute tool in the Flai MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on transport_stop? +

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

What risk level is transport_stop? +

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

Can I rate-limit transport_stop? +

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

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

transport_stop is provided by the Flai MCP server (kaupau/flai-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.