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CodexPartial workaroundUpdated Aug 20, 2026

Codex Browser fails because browser-client is not trusted

Diagnose Codex Browser plugin failures caused by a missing native pipe trust bridge or a browser-client path outside configured trusted code paths.

Exact error

Match the message before using the fix

privileged native pipe bridge is not available; browser-client is not trustedTrusted RPC dependency must resolve within a configured trusted code pathbrowser-service.mjs is not within a configured trusted code path

Quick answer

Start here

First separate page rendering from browser control: if the in-app browser opens sites but plugin initialization returns a trust or native-pipe error, the target website is not the cause. Restart on the current Codex build and use only the version-matched bundled client path supplied by the installed Browser skill. An older report found a bundled marketplace path worked when the cache path did not; direct Playwright also worked as a temporary testing fallback. Do not add arbitrary paths or hashes to the trusted list.

Diagnosis

Why it happens

  • In one branch, the runtime advertised Chrome and in-app browser backends but did not inject the privileged native pipe bridge into the Node runtime.
  • In the newer branch, the bundled `browser-service.mjs` resolved outside the runtime's configured trusted code paths.
  • The same symptom can cross Windows/WSL boundaries where a Windows Node process receives a WSL-style plugin path; that is a related but distinct path-normalization branch.

Safest first

Fixes, in order

01

Confirm Browser control—not page rendering—is failing

Applies when: When the browser window opens but the agent cannot initialize a controllable session

The source reports confirmed the target page and normal browser rendering were healthy.

  1. Open a harmless public page in the in-app browser without automation.
  2. Record the complete plugin initialization error and bundled plugin version.
  3. Confirm whether the message names `browser-client`, `browser-service.mjs`, trusted code paths, or the native pipe bridge.
  4. Do not debug the target website if it renders normally.

Expected: Manual rendering works while automation fails before a browser session is created.

02

Reload the current bundled plugin path

Applies when: Native Windows Desktop where the error points into a stale cache or an untrusted bundled path

The older report was path-sensitive: an official bundled marketplace source path worked while its cache path failed.

  1. Update Codex through its normal official channel and fully restart the app.
  2. Start a new task so it receives the current Browser skill instructions and runtime metadata.
  3. Import only the exact versioned `browser-client.mjs` path supplied by that installed skill.
  4. Do not copy the client to a custom directory or manually invent trust hashes.

Expected: The runtime accepts the version-matched official path and returns an available Browser binding, or reproduces the still-open trust-path defect cleanly.

03

Use direct Playwright as a temporary test fallback

Applies when: Local web testing when Browser plugin initialization remains blocked and project policy allows standalone Playwright

Direct Playwright controlled the same target successfully in the original native-pipe report; it bypasses the plugin bridge rather than fixing it.

  1. Use an existing project Playwright setup when one is already available.
  2. Run only the bounded navigation or screenshot check needed for the task.
  3. Keep authentication and personal browser profiles out of the fallback session.
  4. Return to the bundled Browser plugin after an official fix.

Expected: The required local UI check completes without claiming the Browser trust path is repaired.

Verification

Prove the fix worked

  1. Initialize the bundled Browser runtime in a new Codex task.
  2. Acquire the advertised in-app or extension browser and read a harmless page title.
  3. Confirm the result uses the bundled Browser path, not the standalone Playwright fallback.

Escalation

If it still fails

  • Record Codex app version, plugin version, exact client/service path, Windows versus WSL runtime, and whether backends are advertised.
  • Do not weaken trusted-code configuration broadly or add hashes copied from another installation.
  • Treat `native pipe bridge is not available` and `Trusted RPC dependency ... trusted code path` as related variants with potentially different sub-causes.

Scope

Environment and version notes

  • The native-pipe report used Codex Desktop 26.506.2212.0; the trusted-RPC-path report used 26.814.41407 on Windows 11.
  • Both source issues remained open on August 20, 2026, so the bundled-path and Playwright workarounds are partial rather than shipped fixes.
  • Sources rechecked August 20, 2026.

Evidence

Sources

Source labels describe the evidence available on the checked date. A closed issue is not automatically a shipped fix.