No connection of BrowserPlugin and BrowsertTools Server

[AndreasBarhainski]

I try to get Browsertools running in Cursor AI.
Experience that everything looks good beside there is no connection established between server and plugin.
Errors in the Plugin:

Trying to connect

Logs in Cursor

Cursor Console when running Server

Any solution for this issue?

[MichaelJuskowicz]

@tedjames
This is happening for me too.

Environment

• OS: Windows 11
• Cursor: 0.47.8 (user setup)
• npx: 10.9.2
• Node: v22.13.1
• Firewall: Disabled
• Port: Verified that port 3025 is free

Steps Taken

1. Using npx:
   • Ran:
     npx @agentdeskai/browser-tools-mcp@1.2.0
   • The output only showed repeated failed discovery attempts:

     Attempting initial server discovery on startup...
     Starting server discovery process
     Will try hosts: 127.0.0.1, 127.0.0.1, localhost
     Will try ports: 3025, 3026, 3027, 3028, 3029, 3030, 3031, 3032, 3033, 3034, 3035
     Checking 127.0.0.1:3025...
     Error checking 127.0.0.1:3025: fetch failed
     Checking 127.0.0.1:3026...
     Error checking 127.0.0.1:3026: fetch failed
     Checking 127.0.0.1:3027...
     Error checking 127.0.0.1:3027: fetch failed
     Checking 127.0.0.1:3028...
     Error checking 127.0.0.1:3028: fetch failed
     Checking 127.0.0.1:3029...
     Error checking 127.0.0.1:3029: fetch failed
     Checking 127.0.0.1:3030...
     Error checking 127.0.0.1:3030: fetch failed
     Checking 127.0.0.1:3031...
     Error checking 127.0.0.1:3031: fetch failed
     Checking 127.0.0.1:3032...
     Error checking 127.0.0.1:3032: fetch failed
     Checking 127.0.0.1:3033...
     Error checking 127.0.0.1:3033: fetch failed
     Checking 127.0.0.1:3034...
     Error checking 127.0.0.1:3034: fetch failed
     Checking 127.0.0.1:3035...
     Error checking 127.0.0.1:3035: fetch failed
     Checking 127.0.0.1:3025...
     Error checking 127.0.0.1:3025: fetch failed
     Checking 127.0.0.1:3026...
     Error checking 127.0.0.1:3026: fetch failed
     Checking 127.0.0.1:3027...
     Error checking 127.0.0.1:3027: fetch failed
     Checking 127.0.0.1:3028...
     Error checking 127.0.0.1:3028: fetch failed
     Checking 127.0.0.1:3029...
     Error checking 127.0.0.1:3029: fetch failed
     Checking 127.0.0.1:3030...
     Error checking 127.0.0.1:3030: fetch failed
     Checking 127.0.0.1:3031...
     Error checking 127.0.0.1:3031: fetch failed
     Checking 127.0.0.1:3032...
     Error checking 127.0.0.1:3032: fetch failed
     Checking 127.0.0.1:3033...
     Error checking 127.0.0.1:3033: fetch failed
     Checking 127.0.0.1:3034...
     Error checking 127.0.0.1:3034: fetch failed
     Checking 127.0.0.1:3035...
     Error checking 127.0.0.1:3035: fetch failed
     Checking localhost:3025...
     Error checking localhost:3025: fetch failed
     Checking localhost:3026...
     Error checking localhost:3026: fetch failed
     Checking localhost:3027...
     Error checking localhost:3027: fetch failed
     Checking localhost:3028...
     Error checking localhost:3028: fetch failed
     Checking localhost:3029...
     Error checking localhost:3029: fetch failed
     Checking localhost:3030...
     Error checking localhost:3030: fetch failed
     Checking localhost:3031...
     Error checking localhost:3031: fetch failed
     Checking localhost:3032...
     Error checking localhost:3032: fetch failed
     Checking localhost:3033...
     Error checking localhost:3033: fetch failed
     Checking localhost:3034...
     Error checking localhost:3034: fetch failed
     Checking localhost:3035...
     Error checking localhost:3035: fetch failed
     No server found during discovery
     Initial server discovery failed. Will try again when tools are used.
     

• Attempted to get the server to try again:
  - Tried "Test Connection" button to cause the server to try again.
  - Under the button I got: "Connection failed: Failed to fetch"
  - Tried asking the Agent to use a tool to cause the server to try again:
  - Agent received: Failed to discover browser connector server. Please ensure it's running.
• Nothing caused it to try again.

2. Local Installation Attempt and Direct Execution with Node:
   • Ran:
     pnpm install @agentdeskai/browser-tools-mcp@1.2.0
   • Ran:
     node .\node_modules\@agentdeskai\browser-tools-mcp\dist\mcp-server.js
   • The output again only shows the discovery attempts with “fetch failed” messages across several ports and does not progress to actually starting the server.

Any insights or suggestions to help resolve this would be greatly appreciated!

[Leee62]

haha guys,check this #86 (comment)

[MichaelJuskowicz]

haha guys,check this #86 (comment)

That's crazy. Thank you so much! I can't believe that was all it was this whole time.

[atrefonas]

You have to run npx @agentdeskai/browser-tools-server@1.2.0 in a terminal before you do anything with npx @agentdeskai/browser-tools-mcp@1.2.0. This is a different command. There are two separate commands that look almost the same. I get this is highly confusing and never explained anywhere.

[juandenver]

Is it possible to run the server inside of a devcontainer? I'd imagine there would be some networking challenges for the client to connect to the server. Plus the ability to read from a local folder because of the cursor config.