Codex Desktop: completed Stop hook details open empty instead of showing hook result

[RealmX1]

What happened?

In recent Codex Desktop builds on macOS, the completed Stop hook result is no longer visible to the user/developer.

After an agent response finishes, Codex shows a hook indicator/button at the end of the response. Previously, the user could inspect the Stop hook result/final report from that UI surface. Currently, clicking the hook button opens nothing useful / an empty details view, so the user cannot see the hook's final report.

This is specifically about the user-visible UI artifact for a completed hook run. It is not a request to inject the hook output into the main agent/model context. Hook output should remain inspectable by the human operator without becoming part of the next model turn.

Why this matters

Stop hooks are often used for post-run checks, review gates, or handoff/report generation. The final hook result is intended for the user/developer to inspect after the agent response completes. If the details panel is empty, the hook can still run but the human loses the report/status surface.

Expected behavior

A completed Stop hook should have an inspectable UI detail surface that shows at least the hook's returned message/output, for example the returned systemMessage or equivalent hook result summary.

The hook result should remain UI-visible only and should not be inserted into the agent conversation/model context.

Actual behavior

The hook indicator/button appears at the end of the agent response, but clicking it does not show the Stop hook's final report/details.

Evidence from a local hook

The hook returns a valid Codex hook payload on stdout. In one recent run, the hook payload shape was produced from code equivalent to:

{
  "continue": true,
  "systemMessage": "review-validate-fix: <status>; reason=<reason_code>; summary=<summary_path>"
}

The corresponding local hook run also wrote its summary artifact successfully, for example:

{
  "status": "cline-kanban-unavailable",
  "reason_code": "cline_kanban_unavailable",
  "message": "CODEX_RVF_FORK_MODE=cline-kanban requires a readable parent transcript/session scope anchor; task was not started."
}

So this does not look like a missing hook result at the hook-process level. The missing piece appears to be the Codex Desktop UI surface that should display the completed hook result to the user.

Environment

• Platform: macOS
• Codex Desktop session metadata observed: originator: Codex Desktop, cli_version: 0.131.0-alpha.9
• Local codex --version: codex-cli 0.130.0
• Hook type: Stop

Related issues / distinction

This sounds related to the app/hooks area but is narrower than #21639. That issue reports hooks no longer running after a Desktop update. In this case, the hook appears to run and produce output/artifacts, but the completed hook result is no longer visible to the user from the Desktop UI.

[Keesan12]

This is a UI provenance regression more than a hook regression. The hook ran, the artifact exists, but the operator lost the receipt surface that explains the run. I would make the Stop-hook details panel show a compact summary plus a stable pointer to the underlying artifact or returned message, even if the full payload stays outside model context. That human-visible receipt layer is exactly what keeps post-run gates useful instead of mysterious.