rpc_launch_app · Rpcclient MCP: Risk & Policy

WHAT IT DOES

What rpc_launch_app does on Rpcclient

AI agents invoke rpc_launch_app to trigger actions in Rpcclient. 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 rpc_launch_app needs a policy

Launching an app is an Execute-category action because it triggers code/operations external to the MCP server itself (the iOS app), and the consequences depend on which app is launched and what that app does. While not Write, Destructive, or Financial in itself, the action has side effects that cannot be undone simply by the tool invocation alone.

From the tool's definition Tool description states 'Launch an app by bundle id or query' — this directly triggers external operations on an iOS device with effects determined by which app is launched.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

rpc_launch_app Rate-limited

rpc_launch_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": {
    "rpc_launch_app": {
      "limits": [
        {
          "counter": "rpc_launch_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 Rpcclient, so you can run agents against it safely.

FAQ

Questions about rpc_launch_app

What does the rpc_launch_app tool do? +

Launch an app by bundle id or query; includes foreground verification result. It is categorised as a Execute tool in the Rpcclient MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on rpc_launch_app? +

Register the Rpcclient MCP server in PolicyLayer and add a rule for rpc_launch_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 Rpcclient. Nothing to install.

What risk level is rpc_launch_app? +

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

Can I rate-limit rpc_launch_app? +

Yes. Add a rate_limit block to the rpc_launch_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 rpc_launch_app completely? +

Set action: deny in the PolicyLayer policy for rpc_launch_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 rpc_launch_app? +

rpc_launch_app is provided by the Rpcclient MCP server (appknox/rpcclient-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.