swap_server · Llauncher MCP: Risk & Policy

WHAT IT DOES

What swap_server does on Llauncher

AI agents invoke swap_server to trigger actions in Llauncher. 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 swap_server needs a policy

Swapping a server model involves stopping a running inference server and starting a new one, which constitutes triggering external operations with side effects. It is not purely destructive (no data is permanently deleted) nor purely a write (it executes process lifecycle changes).

From the tool's definition "Replace the model on this port with a different one" — stops an existing server instance and starts a new one with a different model, triggering external lifecycle operations

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

swap_server Rate-limited

swap_server 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": {
    "swap_server": {
      "limits": [
        {
          "counter": "swap_server_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 Llauncher, so you can run agents against it safely.

FAQ

Questions about swap_server

What does the swap_server tool do? +

Replace the model on this port with a different one. It is categorised as a Execute tool in the Llauncher MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on swap_server? +

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

What risk level is swap_server? +

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

Can I rate-limit swap_server? +

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

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

swap_server is provided by the Llauncher MCP server (shanevcantwell/llauncher). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.