Autocompact fails #18572

What version of Codex CLI is running?

codex-cli 0.121.0

What subscription do you have?

Pro

Which model were you using?

gpt-5.3-codex-spark xhigh

What platform is your computer?

Darwin 25.4.0 arm64 arm

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

Ghostty

What issue are you seeing?

Autocompact feature started to fail since recently, codex (both app or cli) fails session with context window exceeded. Not sure is it related to model (5.3 spark) or the software itself.

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"
  }
}

What steps can reproduce the bug?

Uploaded thread: 019da615-927e-7fc1-8b32-c0e3276bae4d

What is the expected behavior?

No response

Additional information

No response