There was another comment that mentioned that there's an issue with port killing code on Windows: https://news.ycombinator.com/item?id=43614145
I just published a new version of the @browsermcp/mcp library (version 0.1.1) that handles the error better until I can investigate further so it should hopefully work now if you're using @browsermcp/mcp@latest.
FWIW, Claude Desktop currently has a bug where it tries to start the server twice, which is why the MCP server tries to kill the process from a previous invocation: https://github.com/modelcontextprotocol/servers/issues/812
Thanks, great job! I like it overall, but I noticed it has some issues entering text in forms, even on google.com. It's able to find a workaround and insert the searched text in the URL, but it would be nice if the entry into forms worked well for UI testing.
1. Kill your Claude Desktop app
2. Click "Connect" in the browser extension.
3. Quickly start your Calude Desktop app.
It will work 50% of the time - I guess the timing must be just right for it to work. Hopefully, the developers can improve this.
Now on to testing :)
2025-04-07T18:43:26.537Z [browsermcp] [info] Initializing server... 2025-04-07T18:43:26.603Z [browsermcp] [info] Server started and connected successfully 2025-04-07T18:43:26.610Z [browsermcp] [info] Message from client: {"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"claude-ai","version":"0.1.0"}},"jsonrpc":"2.0","id":0} node:internal/errors:983 const err = new Error(message); ^
Error: Command failed: FOR /F "tokens=5" %a in ('netstat -ano ^| findstr :9009') do taskkill /F /PID %a at genericNodeError (node:internal/errors:983:15) at wrappedFn (node:internal/errors:537:14) at checkExecSyncError (node:child_process:882:11) at execSync (node:child_process:954:15)