[Feature Request] Connect to existing browser instance by HTTP URL

[jack5github]

Chrome DevTools Protocol endpoint URLs change every time such a browser is opened, making --cdp-endpoint an inviable argument for repeated testing, especially since both the user and the LLM could close the browser accidentally. The process for using a remote-debugging-enabled Chrome instance with the Playwright MCP server currently looks like this:

1. Open a terminal and execute cd "C:\Program Files\Google\Chrome\Application".
2. Execute .\chrome.exe --remote-debugging-port=9222 --user-data-dir="C:\ChromeRemoteDebuggingUserData".
3. In Chrome, navigate to http://localhost:9222/json/version and copy the value of webSocketDebuggerUrl.
4. Configure a "playwright" MCP server with command npx @playwright/mcp@latest --cdp-endpoint=<webSocketDebuggerUrl>. The need to update this every time the Chrome browser is launched is the bottleneck that makes continued testing an issue.

The Chrome DevTools MCP server offers a --browser-url argument that accepts the value http://localhost:9222/, which allows it to connect to the browser instance without fail, even if it has been closed and re-opened. I propose that a similar argument be added to the Playwright MCP server.

[pavelfeldman]

You should be able to just point at http://localhost:9222, none of these steps are needed.

[BenRacicot]

Jack Stringer (@jack5github) is correct. This is a downgrade when combined with chrome-devtools which just works without flags in 146+.

It would be a much better DX if we could run both together now that remote-debugging is a checkbox.

Would Pavel Feldman (@pavelfeldman) be open to revisiting this?