browser-tools-mcp with Cursor: 'Could not establish connection. Receiving end does not exist.'

Question

Using the browser-tools-mcp Chrome extension with Cursor on macOS and Windows 11 Chrome, background.js logs "Uncaught (in promise) Error: Could not establish connection. Receiving end does not exist." The browser-tools server appears to run and print logs, but Cursor shows no extension logs. What causes this and is there a confirmed fix?

Originally asked on GitHub: https://github.com/AgentDeskAI/browser-tools-mcp/issues/147

AgentArmorHQ team · Accepted Answer

This issue was closed with no maintainer explanation, and no participant confirmed a fix. One user reported the error disappeared on its own, and another commenter advised making sure the browser-tools server is launched.

One user shared the configuration they used, pinning version 1.2.0:

```json
{
  "mcpServers": {
    "MCP Navegador": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "@agentdeskai/browser-tools-mcp@1.2.0"]
    }
  }
}
```

They ran this command via cmd to activate the server:

```
npx @agentdeskai/browser-tools-server@1.2.0
```

That commenter did not state whether this resolved the error, so treat it as a configuration reference rather than a confirmed fix. A separate comment notes Chrome blocks the chrome.debugger API on chrome-extension:// pages, so the extension cannot interact with tabs whose URL starts with chrome-extension://.

General advice, not from the thread: if the server is running but the client still shows no logs, reload the extension at chrome://extensions and restart the MCP client.

AgentArmorHQ team · Answer

**What @smilingkylan tried on GitHub** (Outcome unclear)

A user advised making sure the server is launched.

Source: https://github.com/AgentDeskAI/browser-tools-mcp/issues/147#issuecomment-2861946961

AgentArmorHQ team · Answer

**What @Diegosch1990 tried on GitHub** (Outcome unclear)

A user shared their mcp.json configuration pinning @agentdeskai/browser-tools-mcp@1.2.0 and said to run npx @agentdeskai/browser-tools-server@1.2.0 via cmd to activate the server.

Source: https://github.com/AgentDeskAI/browser-tools-mcp/issues/147#issuecomment-2825828083

AgentArmorHQ team · Answer

**What @Diegosch1990 tried on GitHub** (Worked)

A user reported the error started working again on its own without any change.

Source: https://github.com/AgentDeskAI/browser-tools-mcp/issues/147#issuecomment-2814322342

AgentArmorHQ team · Answer

**What @brianorwhatever tried on GitHub** (Outcome unclear)

A user reported the browser-tools server seemed to be running and showed logs, but Cursor did not show any extension logs.

Source: https://github.com/AgentDeskAI/browser-tools-mcp/issues/147#issuecomment-2798943270

AgentArmorHQ team · Answer

**What a GitHub user tried on GitHub** (Outcome unclear)

The reporter posted two screenshots of the Chrome extension error but included no reproduction steps, configuration, or commands.

Source: https://github.com/AgentDeskAI/browser-tools-mcp/issues/147

browser-tools-mcp with Cursor: 'Could not establish connection. Receiving end does not exist.'

6 answers

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browser-tools-mcp with Cursor: 'Could not establish connection. Receiving end does not exist.'

6 answers

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