Codex Desktop 26.825.51511: cron automations fail instantly — stream disconnected before completion

What version of the Codex App are you using (From “About Codex” dialog)?

26.825.51511 (macOS; upgraded from 26.825.41651 on 2026-09-02)

What subscription do you have?

API key mode (custom gateway), no ChatGPT subscription

What platform is your computer?

Darwin 25.6.0 arm64 arm

What issue are you seeing?

Every run of a cron automation ("禅道需求进度每日统计") fails within 1–2 seconds with:

stream disconnected before completion: stream closed before response.completed

No model output is ever produced, so the task never starts executing (no tools are run). This started immediately after upgrading to 26.825.51511 on 2026-09-02; the same automation ran fine on 2026-08-31 and 2026-09-01 under the previous app version.

Key observation: after the upgrade, the automation context is injected as a function_call_output item (name "automation_update") as the very first item of the conversation; before the upgrade it was injected as a plain user text message with byte-identical content. Ordinary chat threads on the same model and gateway work normally at the same time.

What steps can reproduce the bug?

Feedback ID: 01a06191-1cef-7fb2-abc0-30ed7cab2531

What is the expected behavior?

Automation runs normally again: restore the pre-upgrade injection (automation context as a plain text message), or assemble requests with a matching function_call preceding the function_call_output, or accept function_call_output as the first item gracefully.

Additional information

Excluded factors: model choice, reasoning effort, and thread state (new threads fail too). The gateway returns HTTP 200 with text/event-stream and then closes the stream immediately, sending no events and no error body — consistent with the server rejecting the request shape outright.

Thread IDs: 01a06175-34ce-7ff2-89e8-4c97a6aa9d70 (original thread), 01a06188-525e-7223-a077-9b9947e737d9 and 01a0618b-4ed8-7fd1-9b60-6a7ec31831d5 ("Run now" threads). Session logs are under ~/.codex/sessions/2026/09/02/.

Start with the session logs under ~/.codex/sessions/2026/09/02/ and the cron automation request path, using feedback ID 01a06191-1cef-7fb2-abc0-30ed7cab2531. Compare the pre-upgrade plain user message with the new function_call_output-first request. Done means the automation stream remains connected through response.completed and produces model output through the custom gateway.