Dev Browser extension stuck on “Connecting”; relay reports extensionConnected=false

[jordyvandomselaar]

Summary

The Dev Browser extension won’t connect to the local relay server. The extension UI stays on “Connecting,” while the relay server continues to report extensionConnected: false.

Environment

• OS: macOS
• Dev Browser skill path: /Users/jordyvandomselaar/.codex/skills/dev-browser
• Relay server URL: http://localhost:9000 (extension endpoint ws://localhost:9000/extension)
• Node: v22.13.1

Steps Tried

1. Started relay server with npm run start-extension in skills/dev-browser.

2. Verified relay output:

   [relay] CDP relay server started
   [relay] HTTP: http://localhost:9000
   [relay] CDP endpoint: ws://localhost:9000/cdp
   [relay] Extension endpoint: ws://localhost:9000/extension
   [relay] Waiting for extension to connect...

3. Checked relay status via client API (getServerInfo), which returned:

   {
   wsEndpoint: 'ws://localhost:9000/cdp',
   mode: 'extension',
   extensionConnected: false
   }

4. Restarted the relay server multiple times; extension still shows “Connecting.”

5. Suggested client-side steps (toggle connect, reload extension, confirm endpoint), but still no connection.

Expected

Extension should connect and relay should show extensionConnected: true.

Actual

Extension UI stays “Connecting” and relay stays “Waiting for extension to connect…”.

Notes

• Initial relay startup required elevated permissions in the sandbox to bind IPC (EPERM when sandboxed).
• If needed, I can provide logs or run additional diagnostics.

[timelf123]

Use 127.0.0.1 instead of localhost

[mwood23]

Seeing the same thing and wasn't able to find a working. I tried 127.0.0.1 and that didn't fix it either.

[DysektAI]

Summary

The Dev Browser extension won’t connect to the local relay server. The extension UI stays on “Connecting,” while the relay server continues to report extensionConnected: false.

Environment

• OS: macOS
• Dev Browser skill path: /Users/jordyvandomselaar/.codex/skills/dev-browser
• Relay server URL: http://localhost:9000 (extension endpoint ws://localhost:9000/extension)
• Node: v22.13.1

Steps Tried

1. Started relay server with npm run start-extension in skills/dev-browser.
2. Verified relay output:
   [relay] CDP relay server started
   [relay] HTTP: http://localhost:9000
   [relay] CDP endpoint: ws://localhost:9000/cdp
   [relay] Extension endpoint: ws://localhost:9000/extension
   [relay] Waiting for extension to connect...
3. Checked relay status via client API (getServerInfo), which returned:
   {
   wsEndpoint: 'ws://localhost:9000/cdp',
   mode: 'extension',
   extensionConnected: false
   }
4. Restarted the relay server multiple times; extension still shows “Connecting.”
5. Suggested client-side steps (toggle connect, reload extension, confirm endpoint), but still no connection.

Expected

Extension should connect and relay should show extensionConnected: true.

Actual

Extension UI stays “Connecting” and relay stays “Waiting for extension to connect…”.

Notes

• Initial relay startup required elevated permissions in the sandbox to bind IPC (EPERM when sandboxed).
• If needed, I can provide logs or run additional diagnostics.

Im not sure what permission fixed it but just had the exact same issue, and first thought was something isn't being allowed.. Right click extension -> "View web permissions" -> Allow Local Network Access, Scrolling and Windows management and Your Device use...

Be aware I think Local Network Access fixed it for me OR I could have just got lucky timing when I toggled them while Codex was running trying to connect... BUT before it was just failing over and over then once I flipped these it it took control instantly and now says "Connected to relay" properly.