Chrome extension side panel cannot connect to local Codex app-server on Windows

Summary

The ChatGPT Chrome Extension side panel displayed “Unable to connect to ChatGPT” and could not connect to the local Codex app-server over a loopback WebSocket (ws://127.0.0.1:<port>/…). The opaque query token from the UI has been intentionally omitted.

Impact

Codex could not control the user's existing Chrome profile through the extension while the error was shown.

Environment

• Windows
• Google Chrome with the ChatGPT Chrome Extension
• Codex Desktop
• Observed on 2026-07-11

Observed behavior

The extension side panel showed:

Unable to connect to ChatGPT Unable to connect to Codex app-server at ws://127.0.0.1:<port>/…

Expected behavior

The extension should reliably connect to the running Codex Desktop app-server, or surface a clear recovery action and diagnostic if the local app-server is unavailable.

Notes

A subsequent lightweight connection check from Codex was able to list the Chrome tabs successfully. This suggests the failure may be intermittent or tied to the local app-server lifecycle/readiness rather than the extension simply being absent or disabled.

Please investigate local app-server startup/restart behavior and the extension's WebSocket reconnect/error reporting on Windows.

Related, but not an exact duplicate: #30688 (Chrome backend unavailable despite extension/native host working).