Codex Desktop cron automation creates empty thread but does not execute prompt

Summary

Codex Desktop cron automations can reach the scheduled time and create a new thread, but the automation prompt is not submitted to the thread and no model response is generated. The resulting thread is empty.

Environment

• OS: Windows 10 Pro x64
• Codex Desktop Windows AppX package: OpenAI.Codex_26.601.2237.0_x64__2p2nqsd0c76g0
• Codex Desktop client version in logs: 26.601.21317
• Codex CLI version in session metadata: 0.136.0-alpha.2
• Model used in test automation: gpt-5.5
• Execution environment: local
• Shell: PowerShell
• Timezone used in automation: Asia/Shanghai / UTC+8

Expected behavior

At the scheduled cron time, Codex should create or open the automation run thread, submit the configured prompt, run the model, and show the resulting message in the thread.

Actual behavior

At the scheduled time, Codex creates a new thread, but the thread has no turns. There is no user message, no prompt submission, and no assistant/model output.

Minimal reproduction

1. Create a cron automation scheduled a few minutes in the future:

kind = "cron"
name = "Cron temporary verification"
prompt = "This is a temporary cron verification. Output one sentence with the current local time."
status = "ACTIVE"
rrule = "DTSTART;TZID=Asia/Shanghai:20260603T150600\nRRULE:FREQ=WEEKLY;BYDAY=WE;BYHOUR=15;BYMINUTE=6;BYSECOND=0"
model = "gpt-5.5"
reasoning_effort = "minimal"
execution_environment = "local"
cwds = ["E:\\\\"]

1. Keep Codex Desktop open and the computer awake.
2. Wait until the scheduled time.
3. Observe that a thread is created but remains empty.

Observed local evidence

• Temporary cron automation was created at local time 2026-06-03 15:04:13.
• Scheduled trigger time was local time 2026-06-03 15:06:00.
• New thread was created at local time 2026-06-03 15:06:40:
• Thread id: 019e8c4e-4461-7681-9e10-f41ac412462c
• Thread title: 素材管理｜Cron临时修复验证
• Session file: %USERPROFILE%\.codex\sessions\2026\06\03\rollout-2026-06-03T15-06-40-019e8c4e-4461-7681-9e10-f41ac412462c.jsonl
• The session file contains only session_meta; it has no user_message, submission_dispatch, run_sampling_request, or assistant response.
• The corresponding log row only shows thread/start:

15:06:40 WARN codex_core::shell_snapshot
app_server.request{otel.name="thread/start" ... client_version="26.601.21317"}:
app_server.thread_start.create_thread{...}:thread_spawn{...}:session_init:
shell_snapshot{thread_id=019e8c4e-4461-7681-9e10-f41ac412462c}:
Failed to create shell snapshot for powershell: Shell snapshot not supported yet for PowerShell

There is no subsequent submission_dispatch or model sampling request for the cron thread.

Notes

• The same machine can run normal interactive Codex turns.
• Heartbeat automations were able to submit heartbeat messages earlier, so this appears specific to cron automation execution after thread creation.
• Existing business cron automations are currently paused, but the minimal ACTIVE cron test above reproduces the failure independently.

Additional reproduction

A second minimal cron test was created to rule out the workspace root, model, and reasoning effort as causes:

kind = "cron"
name = "Cron current workspace retest"
prompt = "Temporary cron retest. Output: cron current workspace test fired, plus the current local time."
status = "ACTIVE"
rrule = "DTSTART;TZID=Asia/Shanghai:20260603T151700\nRRULE:FREQ=WEEKLY;BYDAY=WE;BYHOUR=15;BYMINUTE=17;BYSECOND=0"
model = "gpt-5.4-mini"
reasoning_effort = "low"
execution_environment = "local"
cwds = ["C:\\Users\\Administrator\\Documents\\<redacted-workspace>"]

Result:

• No thread appeared in thread search for the automation name.
• No prompt output appeared in sessions.
• Logs showed another thread/start at local time 2026-06-03 15:17:40 for thread 019e8c58-572d-70c2-957c-4a5ce5c4d5b2.
• No subsequent prompt submission or model run was observed.

This suggests the failure is not specific to E:\\, gpt-5.5, or reasoning_effort = "minimal".