# emulate

Emulates various features on the selected page.

Agent View of the PolicyLayer registry record for `emulate`. HTML page: https://policylayer.com/tools/async23-chrome-devtools-mcp/emulate

## Facts

- Tool: `emulate`
- Server: Chrome Devtools (`@async23/chrome-devtools-mcp`) — https://policylayer.com/tools/async23-chrome-devtools-mcp.md
- Install: `npx -y @async23/chrome-devtools-mcp`
- Homepage: https://github.com/Async23/chrome-devtools-mcp
- Risk category: Execute (High risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "emulate",
    "arguments": {}
  }
}
```

## Why emulate is rated High

This tool executes browser emulation operations that trigger external side effects on the Chrome instance. While it does not delete data (not Destructive) or move money (not Financial), it actively manipulates browser state and behavior, similar to sibling Execute tools like evaluate_script and click. The effects are dependent on which emulation features are targeted and their parameters.

From the tool's own definition: "Tool named 'emulate' on Chrome DevTools MCP server with sibling tools like 'evaluate_script', 'click', 'drag', 'fill' that trigger external browser operations."

## Use case

AI agents invoke emulate to trigger actions in Chrome Devtools. 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.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Chrome Devtools:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "emulate": {
      "limits": [
        {
          "counter": "emulate_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Chrome Devtools (49)

- `close_heapsnapshot` — Destructive — https://policylayer.com/tools/async23-chrome-devtools-mcp/close-heapsnapshot.md
- `close_page` — Destructive — https://policylayer.com/tools/async23-chrome-devtools-mcp/close-page.md
- `uninstall_extension` — Destructive — https://policylayer.com/tools/async23-chrome-devtools-mcp/uninstall-extension.md
- `click` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/click.md
- `click_at` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/click-at.md
- `drag` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/drag.md
- `evaluate` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/evaluate.md
- `evaluate_script` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/evaluate-script.md
- `execute_3p_developer_tool` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/execute-3p-developer-tool.md
- `execute_webmcp_tool` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/execute-webmcp-tool.md
- `fill_form` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/fill-form.md
- `handle_dialog` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/handle-dialog.md
- `hover` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/hover.md
- `install_extension` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/install-extension.md
- `lighthouse_audit` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/lighthouse-audit.md
- `navigate` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/navigate.md
- `performance_start_trace` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/performance-start-trace.md
- `performance_stop_trace` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/performance-stop-trace.md
- `press_key` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/press-key.md
- `reload_extension` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/reload-extension.md
- `resize_page` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/resize-page.md
- `screencast_stop` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/screencast-stop.md
- `select_page` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/select-page.md
- `trigger_extension_action` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/trigger-extension-action.md
- `type_text` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/type-text.md
- `wait_for` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/wait-for.md
- `compare_heapsnapshots` — Read — https://policylayer.com/tools/async23-chrome-devtools-mcp/compare-heapsnapshots.md
- `get_console_message` — Read — https://policylayer.com/tools/async23-chrome-devtools-mcp/get-console-message.md
- `get_heapsnapshot_class_nodes` — Read — https://policylayer.com/tools/async23-chrome-devtools-mcp/get-heapsnapshot-class-nodes.md
- `get_heapsnapshot_details` — Read — https://policylayer.com/tools/async23-chrome-devtools-mcp/get-heapsnapshot-details.md
- …and 19 more: https://policylayer.com/tools/async23-chrome-devtools-mcp.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=async23-chrome-devtools-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/async23-chrome-devtools-mcp
