[Windows] Codex Desktop app-server repeatedly restarts and loses tool call outputs

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

26.820.80927

What subscription do you have?

Pro

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64 (Windows 11)

What issue are you seeing?

Codex Desktop repeatedly terminates or restarts its app-server while an active task is executing tool calls. The UI is then reloaded or reset, and the active turn is left in an interrupted state.

This is not caused by a failing repository command. In the most recent occurrences, the PowerShell/Git/Python commands completed successfully, but the Codex backend terminated before attaching the tool result to the conversation history.

The local Codex logs contain the following direct error:

Custom tool call output is missing for call id

For the affected task, 2 out of approximately 337 exec tool calls are missing their corresponding recorded outputs. After reopening or resuming the task, Codex reconstructs the incomplete history, encounters the same missing tool output, and the interruption can repeat.

The problem has occurred in multiple Codex tasks since August 27, 2026. More than 90 occurrences of the same missing custom-tool-output error were recorded locally.

Windows Error Reporting and Crashpad contain no corresponding native crash dump. The machine also had approximately 179 GB of free memory, so this does not appear to be caused by memory pressure.

UI telemetry also reported state synchronization errors including:

• Received turn/started for unknown conversation
• streaming threads without an active runtime

This appears to be a Codex Desktop app-server/tool-call persistence or state synchronization bug, potentially amplified by resuming a long-running task with an incomplete tool-call record.

What steps can reproduce the bug?

Feedback ID: 01a041d5-1ee5-7842-a34a-cd3b6c899d8a

What is the expected behavior?

Codex should persist the completed tool result, attach it to the correct tool call, complete the active turn, and continue the task without restarting the app-server.

The app-server terminates during or immediately after a tool call. The command may finish successfully, but its result is not attached to the conversation history. The turn is left interrupted, and resuming the task can reproduce the same failure.

Additional information

Affected Codex thread ID:
01a041d5-1ee5-7842-a34a-cd3b6c899d8a

Feedback ID:
01a041d5-1ee5-7842-a34a-cd3b6c899d8a

One confirmed missing call:
call_Euw81SAf1P6CfscQKHQt5ZbX

Observed app versions:

• 26.820.60940
• 26.820.71523
• 26.820.80927

Current bundled CLI:
codex-cli 0.150.0-alpha.8

The issue occurred across multiple backend process restarts and multiple Codex tasks. No native Windows crash dump was generated.

Start by tracing app-server handling of the Custom tool call output is missing for call id error and the persistence path for tool results and interrupted turns. Use the supplied feedback/thread ID and Windows logs to investigate the restart and resume sequence; done means completed outputs remain attached, turns finish, and resuming does not reproduce the synchronization failure.