computer_type · LocalAnt MCP: Risk & Policy

WHAT IT DOES

What computer_type does on LocalAnt

AI agents invoke computer_type to trigger actions in LocalAnt. 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 computer_type needs a policy

This tool simulates keyboard input on the local machine, which constitutes an external operation/browser or desktop automation action. It could be used to inject arbitrary text or commands into focused applications (e.g., a terminal, code editor, browser address bar), making it an Execute-category risk.

From the tool's definition 'Type text at the current focus (newlines become Return presses)' — triggers keyboard input actions on the host PC; 'Requires approval (risk 3)'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

computer_type Rate-limited

computer_type 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": {
    "computer_type": {
      "limits": [
        {
          "counter": "computer_type_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 LocalAnt, so you can run agents against it safely.

FAQ

Questions about computer_type

What does the computer_type tool do? +

Type text at the current focus (newlines become Return presses). Requires approval (risk 3). It is categorised as a Execute tool in the LocalAnt MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on computer_type? +

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

What risk level is computer_type? +

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

Can I rate-limit computer_type? +

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

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

computer_type is provided by the LocalAnt MCP server (yuga-hashimoto/localant). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.