Before submitting
Area
apps/desktop
Steps to reproduce
- Start T3 Code on Windows using the installed desktop app/package.
- Open a project/session using the Codex provider.
- Ask the agent to use or inspect the in-app browser / Browser plugin.
- The agent follows the Browser skill bootstrap path and attempts to discover the IAB backend.
- In the session, run the browser discovery check:
const { setupBrowserRuntime } = await import("C:/Users/Alon-TUF/.codex/plugins/cache/openai-bundled/browser/26.519.21041/scripts/browser-client.mjs");
await setupBrowserRuntime({ globals: globalThis });
const browsers = await agent.browsers.list();
nodeRepl.write(JSON.stringify(browsers, null, 2));
- The returned browser list is empty.
Expected behavior
T3 Code should start or expose the Codex in-app browser backend for Codex sessions when browser tooling is available, so the agent can attach to the shared in-app browser, inspect local routes, take screenshots, and interact with pages through the documented Browser/IAB flow.
Actual behavior
The Browser skill files are present, and the agent can import the browser client, but no IAB backend is registered in the session.
The discovery result is:
Because no browser backend is exposed, agent.browsers.get("iab") cannot be used. The agent has to fall back to standalone Playwright from the repo/environment, which verifies local routes but does not use the T3 Code/Codex shared in-app browser surface.
Impact
Major degradation or frequent failure
Version or commit
T3 Code 0.0.24 via winget (T3Tools.T3Code)
Environment
OS: Microsoft Windows NT 10.0.26200.0
T3 Code: 0.0.24, installed via winget package T3Tools.T3Code
Shell: PowerShell 5.1.26100.8328
Node: v24.16.0
Bun: 1.3.14
Codex CLI: codex-cli 0.135.0
Logs or stack traces
Browser discovery check:
const { setupBrowserRuntime } = await import("C:/Users/Alon-TUF/.codex/plugins/cache/openai-bundled/browser/26.519.21041/scripts/browser-client.mjs");
await setupBrowserRuntime({ globals: globalThis });
const browsers = await agent.browsers.list();
nodeRepl.write(JSON.stringify(browsers, null, 2));
Output:
[]Screenshots, recordings, or supporting files
No screenshot attached. The key diagnostic is the empty browser backend list returned by agent.browsers.list().
Workaround
Use standalone Playwright or a normal browser against the local dev server instead of the Codex/T3 Code in-app browser.
Example:
npm run dev
npx playwright test
This verifies the app route, but does not provide the shared in-app browser backend expected by Codex Browser tooling.
Additional context
This may overlap with upstream Codex Browser/IAB behavior on Windows, but in this T3 Code session the observable problem is that no browser backend is exposed at all to the Codex Browser runtime.
Related upstream Codex reports:
Before submitting
Area
apps/desktop
Steps to reproduce
Expected behavior
T3 Code should start or expose the Codex in-app browser backend for Codex sessions when browser tooling is available, so the agent can attach to the shared in-app browser, inspect local routes, take screenshots, and interact with pages through the documented Browser/IAB flow.
Actual behavior
The Browser skill files are present, and the agent can import the browser client, but no IAB backend is registered in the session.
The discovery result is:
Because no browser backend is exposed,
agent.browsers.get("iab")cannot be used. The agent has to fall back to standalone Playwright from the repo/environment, which verifies local routes but does not use the T3 Code/Codex shared in-app browser surface.Impact
Major degradation or frequent failure
Version or commit
T3 Code 0.0.24 via winget (
T3Tools.T3Code)Environment
Logs or stack traces
Browser discovery check: const { setupBrowserRuntime } = await import("C:/Users/Alon-TUF/.codex/plugins/cache/openai-bundled/browser/26.519.21041/scripts/browser-client.mjs"); await setupBrowserRuntime({ globals: globalThis }); const browsers = await agent.browsers.list(); nodeRepl.write(JSON.stringify(browsers, null, 2)); Output: []Screenshots, recordings, or supporting files
No screenshot attached. The key diagnostic is the empty browser backend list returned by
agent.browsers.list().Workaround
Use standalone Playwright or a normal browser against the local dev server instead of the Codex/T3 Code in-app browser.
Example:
npm run dev npx playwright testThis verifies the app route, but does not provide the shared in-app browser backend expected by Codex Browser tooling.
Additional context
This may overlap with upstream Codex Browser/IAB behavior on Windows, but in this T3 Code session the observable problem is that no browser backend is exposed at all to the Codex Browser runtime.
Related upstream Codex reports: