dom_type · Hermes Computer Use MCP: Risk & Policy

WHAT IT DOES

What dom_type does on Hermes Computer Use

AI agents invoke dom_type to trigger actions in Hermes Computer Use. 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 dom_type needs a policy

This tool interacts with a live browser by injecting text into form fields, which can trigger form submissions, search queries, login attempts, or other actions with real-world consequences. It is part of a browser automation server designed to evade anti-bot detection, amplifying misuse risk. The action itself is an Execute-level browser interaction rather than a simple write to a data store.

From the tool's definition 'dom_type' sets the value of an input/textarea/contenteditable element in a real Chrome browser driven by OS-level mouse/keyboard automation

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

dom_type Rate-limited

dom_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": {
    "dom_type": {
      "limits": [
        {
          "counter": "dom_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 Hermes Computer Use, so you can run agents against it safely.

FAQ

Questions about dom_type

What does the dom_type tool do? +

Set the value of an input / textarea / contenteditable matching the. It is categorised as a Execute tool in the Hermes Computer Use MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on dom_type? +

Register the Hermes Computer Use MCP server in PolicyLayer and add a rule for dom_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 Hermes Computer Use. Nothing to install.

What risk level is dom_type? +

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

Can I rate-limit dom_type? +

Yes. Add a rate_limit block to the dom_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 dom_type completely? +

Set action: deny in the PolicyLayer policy for dom_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 dom_type? +

dom_type is provided by the Hermes Computer Use MCP server (noah3521/hermes-computer-use). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.