[macOS][26.1027.30824] Visible in-app browser cannot bind: Browser is not available: iab

Environment

• Codex desktop app on macOS.
• Installed version: 26.1027.30824, build 22943, production channel, verified through the app update-check tool.
• Configured updater reports up_to_date.
• Exact macOS version and subscription were not collected.
• User reports this began October 30, 2026, in the afternoon (America/Sao_Paulo). An app update as the trigger has not been established.

Issue

The in-app browser visibly opens and loads a website, but the assistant cannot connect to it using the supported Browser runtime. The page's current URL and one open tab are supplied in ambient browser context, while browser selection and active-tab inspection both return:

Browser is not available: iab

This prevents authorized page inspection and browser interaction despite successful visible page loading.

Observed sequence and direct evidence

1. Initialize the bundled Browser runtime following the supplied control-in-app-browser skill.
2. Select the in-app browser with agent.browsers.get("iab").
3. Receive Browser is not available: iab.
4. Follow the runtime's bootstrap-troubleshooting guidance and inspect browser inventory once. It lists only Codex MCP Apps, type mcpapps; there is no iab browser provider.
5. Request page opening through the supported open_in_codex browser target. The tool returns status: "queued".
6. The user confirms the page loaded, and subsequent ambient context reports one in-app-browser tab with the expected website URL.
7. Attempt the skill's supported active-tab context RPC:

await nodeRepl.rpc('browser', {
  method: 'execute',
  params: {
    type: 'browser_user_get_tab_context',
    browser_id: 'iab'
  }
});

It also returns Browser is not available: iab. The same minimal check was repeated after the user reported restarting the app and computer, and the error persisted.

Troubleshooting already completed

• User reports fully restarting the app and rebooting the computer without recovery.
• The app update-check tool confirms the installed build is up to date.
• Browser skill and runtime entry point are available; runtime initialization succeeds.
• Actual browser selection and tab-context inspection fail.
• A fresh-chat comparison has been suggested but has not been confirmed or independently tested in this report.
• No plugin configuration, permissions, browser profiles, caches, cookies, signed app files, or security guards were changed.

Expected behavior

A visible in-app-browser tab in the current chat should be discoverable and controllable through the supported Browser integration, or the app should explain the missing connection and provide a supported recovery action.

Related reports; shared cause not established

• #56873: same Browser is not available: iab error and discovery listing only Codex MCP Apps, on Windows.
• #58346: same macOS desktop version and missing browser control, but that report describes missing callable tools; here the Browser runtime entry point exists and fails at provider selection.
• #58236: same version/build on macOS with a preserved-tab failure, but a different browser.user is unavailable error.

Please investigate in-app-browser provider registration and routing for this macOS build and provide a supported fix. The evidence does not establish the internal root cause or a general service outage.

Prepared with AI assistance at the user's explicit request. Private website URLs, local paths, conversation/session IDs, account identifiers, screenshots, raw logs, credentials and business data are intentionally omitted.