Windows: Chrome side panel cannot control tabs because browser-client path is reported missing despite valid native host

What version of the Codex App are you using (From “About Codex” dialog)?

26.818.4152.0

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

On Windows, the Codex Chrome side panel loads and can read the active page, but it cannot click, type, navigate, or otherwise control Chrome.

The side panel reports that the Codex Chrome native host did not provide a browser-client path. However, local diagnostics show that the native-host installation is valid:

• Codex App: 26.818.4152.0
• Google Chrome: 151.0.7922.173
• Chrome extension: 1.2.27268.51612
• Bundled Chrome plugin/runtime: 26.818.32112
• Registry key exists:
  HKCU\Software\Google\Chrome\NativeMessagingHosts\com.openai.codexextension
• Registry value points to:
  C:\Users\timgi\AppData\Local\OpenAI\extension\com.openai.codexextension.json
• The native-host manifest exists and points to extension-host.exe.
• chrome-native-hosts-v2.json contains a valid browserClientPath.
• A direct native-messaging handshake returns the non-null browserClientPath successfully.
• Nevertheless, a newly created Chrome side-panel chat is initialized with browser control disabled because it claims that no browser-client path was provided.

Reinstalling the Codex App, Chrome plugin, and Chrome extension did not help. Restarting the Codex processes, fully restarting Chrome, and creating a new side-panel chat also did not help.

The same Chrome tabs can be controlled from the main Codex App after restart, so the failure appears to occur specifically while passing the native-host runtime configuration into the Chrome side-panel chat.

Affected chat ID:
01a0285d-2803-72a2-8106-a0cbdce2d306

What steps can reproduce the bug?

1. Open an authenticated website such as the YouTube Community page in Google Chrome.
2. Open the ChatGPT/Codex Chrome side panel.
3. Start a new Codex chat.
4. Ask Codex to open the Community post field and enter TEST without publishing it.
5. Codex can see the page and the post field, but reports that it cannot click or type because the native host did not provide a browser-client path.
6. Restart Chrome and repeat the test in another newly created side-panel chat. The same error occurs.

What is the expected behavior?

The Chrome side-panel chat should receive the valid browserClientPath from the installed native host and should be able to click, type, and navigate in the active Chrome tab.

Additional information

The failure is specific to the Chrome side-panel chat. After restarting Chrome, the same Chrome tabs can be controlled successfully from the main Codex App.

On German Windows, reg.exe displays the default registry value as "(Standard)" instead of "(Default)". A diagnostic checker that searches only for the English label may therefore incorrectly report that the registry value is missing.

No content was entered or published on YouTube during the failed tests.

Start by tracing how chrome-native-hosts-v2.json and the native-messaging handshake provide browserClientPath to a newly created Chrome side-panel chat. Compare that path with the main Codex App flow, using the registry manifest and extension-host.exe details from the report as inputs. Done means the side-panel chat receives the valid path and can control the active tab without reg.exe label assumptions.