browser_dialog · Wmux MCP: Risk & Policy

WHAT IT DOES

What browser_dialog does on Wmux

AI agents invoke browser_dialog to trigger actions in Wmux. 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 browser_dialog needs a policy

This tool triggers external browser automation behavior — it registers a handler that automatically accepts or dismisses browser dialogs when they appear. This is an automated browser action that can influence page flow (e.g., accepting a beforeunload dialog could allow navigation away from a page with unsaved data, or confirming a destructive action dialog).

From the tool's definition Pre-register a handler for the next browser dialog (alert, confirm, prompt, beforeunload). The handler will automatically accept or dismiss the dialog when it appears.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser_dialog Rate-limited

browser_dialog 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": {
    "browser_dialog": {
      "limits": [
        {
          "counter": "browser_dialog_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 Wmux, so you can run agents against it safely.

FAQ

Questions about browser_dialog

What does the browser_dialog tool do? +

Pre-register a handler for the next browser dialog (alert, confirm, prompt, beforeunload). The handler will automatically accept or dismiss the dialog when it appears. It is categorised as a Execute tool in the Wmux MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on browser_dialog? +

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

What risk level is browser_dialog? +

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

Can I rate-limit browser_dialog? +

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

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

browser_dialog is provided by the Wmux MCP server (openwong2kim/wmux). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.