[Windows Desktop] Browser Use unavailable: js_repl removed but browser_use still enabled

Open 💬 3 comments Opened Jun 20, 2026 by alfep

💡 Likely answer: A maintainer (github-actions[bot], contributor) responded on this thread — see the highlighted reply below.

Summary

The in-app browser sidebar is visible and shows the current URL (e.g. x.com/home), but Codex cannot control it because the mcp__node_repl__js tool is never exposed to agent sessions.

This makes @browser, @browser-use, and @computer-use plugins completely non-functional on Windows Desktop.

Environment

| Field | Value |
|-------|-------|
| Codex Desktop | 26.616.5445.0 (Microsoft Store / WindowsApps) |
| app-server CLI |

View original on GitHub ↗

3 Comments

github-actions[bot] contributor · 2 months ago

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

#29224
#29215
#29199
#29211
#29212

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alfep · 2 months ago

Root cause

The in-app browser sidebar is visible, but the agent session does not actually receive a usable browser-control bridge in this Windows Desktop setup.

That means the UI suggests the feature is available, but control never reaches the session that needs it.

What should be fixed

Expose the browser-control bridge to the agent session when the in-app browser is present.
If that bridge is not available in a given Windows build, do not advertise browser_use/side-browser control as available.
Return a clear error like Browser control unavailable in this environment instead of failing silently.
Keep one control path for the side browser, so navigation, click, and verification all use the same backend.
Add a basic end-to-end test: open x.com/home, verify URL/title, and perform one simple interaction from the agent session.

In short

This is not an X.com problem and not a stale-build problem. The issue is the missing control bridge between Codex Desktop and the in-app browser session.

siweigong309-create · 3 days ago

Additional Windows reproduction with a confirmed version boundary and rollback control:

Windows 11 24H2 x64, build 26100.9168
Working combination: Codex AppX 26.803.5235.0; Browser/Chrome/Computer Use 26.803.41515; cua_node 0.0.6/20260723162306-088049353ddc
Regressed after Microsoft Store/AppX replacement: Codex AppX 26.818.2441.0, while the available bundled Browser/Chrome/Computer Use components were still older versions
Symptom: the Browser capability/sidebar remained visible, but mcp__node_repl__js was not exposed to the task, so built-in browser tabs could not be listed or controlled
Control test: restoring the exact 26.803.5235.0 app/plugin/runtime combination restored mcp__node_repl__js immediately; iab.user.openTabs() then succeeded (it returned [] because no tab was open)

This has reproduced more than once on the same machine after Codex app upgrades. The rollback control suggests a Windows app/plugin/runtime registration or version-reconciliation regression, rather than a target webpage or sign-in problem.

For privacy, I did not inspect or include browser history, cookies, account identifiers, project contents, or full logs.