Error running remote compact task while using 5.3codex-spark

What version of Codex CLI is running?

codex-cli 0.142.0 with the codex desktop

What subscription do you have?

Pro 5x

Which model were you using?

5.3codex-spark

What platform is your computer?

Not provided.

What terminal emulator and version are you using (if applicable)?

Not provided.

What issue are you seeing?

While working in Codex, the session hit:

Error running remote compact task: {
"error": {
"message": "Your input exceeds the context window of this model. Please adjust your input and try again.",
"type": "invalid_request_error",
"param": "input",
"code": "context_length_exceeded"
}
}

and then displayed:

Codex ran out of room in the model's context window. Start a new thread or clear earlier history before retrying.

The same behavior appears to align with context_length_exceeded/remote compaction failures being reported in other open issues.

What steps can reproduce the bug?

1. Use model 5.3codex-spark in a Codex session.
2. Continue with task until remote compaction is triggered (or manual /compact equivalent is invoked).
3. Receive Error running remote compact task and the context-window message, preventing normal continuation of the same thread.

What is the expected behavior?

Remote compaction should recover from large context state and complete or offer a safe handoff path without forcing the user to lose context by starting over.

Additional information

• This appears to be another occurrence of the ongoing compaction regression around context_length_exceeded.
• Please let me know if you want me to attach extra diagnostics (thread id/session id, codex version, platform, and full logs).