Skip to content

Codex Desktop context compaction fails with /responses/compact 404 on Windows #38370

Open
Open
Codex Desktop context compaction fails with /responses/compact 404 on Windows#38370
Labels
appIssues related to the Codex desktop appbugSomething isn't workingcontextIssues related to context management (including compaction)windows-osIssues related to Codex on Windows systems

Description

@17755834648a-cmd
17755834648a-cmd
opened on Aug 13, 2026

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

26.506.3741.0

What subscription do you have?

ChatGPT Plus

What platform is your computer?

No response

What issue are you seeing?

Codex Desktop works normally until the conversation reaches the automatic context compaction threshold.

When context compaction is triggered, the UI displays:

“Context automatically compacted”

Immediately afterwards, Codex returns:

Error running remote compact task: unexpected status 404 Not Found
url: https://chatgpt.com/backend-api/codex/responses/compact

After this happens, the conversation cannot continue normally. Sending another message causes the same remote compact 404 error again.

I have reproduced this issue in multiple newly-created Codex Desktop conversations.

Environment:

  • Windows 11 x64
  • ChatGPT Plus
  • Codex Desktop: latest available version
  • Model: GPT-5.5
  • Reasoning level tested: High / Extra High
  • Codex CLI installed separately: 0.147.0

The problem occurs specifically when automatic context compaction is triggered.

What steps can reproduce the bug?

  1. Open Codex Desktop on Windows.
  2. Start a new conversation using GPT-5.5.
  3. Work normally in the conversation and let the context grow.
  4. Continue until Codex automatically triggers context compaction.
  5. The UI displays “Context automatically compacted”.
  6. The request to /backend-api/codex/responses/compact returns HTTP 404.
  7. Send another message in the same conversation.
  8. Codex attempts context compaction again and returns the same 404 error.

This has been reproduced in multiple newly-created conversations, not just one old or unusually long thread.

What is the expected behavior?

No response

Additional information

No response

Activity

  1. 17755834648a-cmd
    added
    appIssues related to the Codex desktop app
    on Aug 13, 2026
  2. github-actions
    added
    bugSomething isn't working
    windows-osIssues related to Codex on Windows systems
    contextIssues related to context management (including compaction)
    on Aug 13, 2026

  3. 17755834648a-cmd commented on Aug 13, 2026

    @17755834648a-cmd
    17755834648a-cmd
    on Aug 13, 2026
    Author

    Platform: Windows 11 x64
    OS build: 10.0.22631
    Codex App: 26.506.3741.0
    Codex CLI: 0.147.0
    Subscription: ChatGPT Plus
    Model: GPT-5.5

  4. github-actions commented on Aug 13, 2026

    @github-actions
    github-actionsBot
    on Aug 13, 2026 – with GitHub Actions
    Contributor

    Potential duplicates detected. Please review them and close your issue if it is a duplicate.

    Powered by Codex Action

  5. Boeblahoebla commented on Aug 18, 2026

    @Boeblahoebla
    Boeblahoebla
    on Aug 18, 2026

    This stuff is constant!

    Image

    Every prompt after that gives same error. Only option is to start a new thread, with obviously all your context gone!

  6. Rina48 commented on Sep 3, 2026

    @Rina48
    Rina48
    on Sep 3, 2026 – with ChatGPT Codex Connector

    I can reproduce this on a newer Windows Codex Desktop build as well.

    Environment:

    • Windows x64
    • ChatGPT Desktop: 1.2026.190.0
    • Codex Desktop: 26.901.1978.0
    • Subscription: ChatGPT Pro
    • Model: GPT-5.6 Sol
    • Reasoning: High
    • Codex CLI is not installed/on PATH; this is the Desktop app path

    The failure occurs when automatic context compaction triggers. I reproduced the same 404 twice:

    Occurrence 1:

    • request id: cc743c4b-4777-4f4d-8a02-534c7ae9ccd3
    • cf-ray: a350711b0afee324-IST

    Occurrence 2:

    • request id: 49d6c14d-c0c2-438e-8972-8a021b2128d9
    • cf-ray: a35131c23a852931-IST

    Both returned:

    Error running remote compact task: unexpected status 404 Not Found: {"detail":"Not Found"}
https://chatgpt.com/backend-api/codex/responses/compact

    After the compaction failure, continuing the same conversation is blocked by the same error. This indicates the issue is still reproducible on Codex Desktop 26.901.1978.0 with GPT-5.6 Sol High.

  7. Boeblahoebla commented on Sep 3, 2026

    @Boeblahoebla
    Boeblahoebla
    on Sep 3, 2026 via email
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    appIssues related to the Codex desktop appbugSomething isn't workingcontextIssues related to context management (including compaction)windows-osIssues related to Codex on Windows systems

    Type

    No type

    Projects

    No projects

      Milestone

      No milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions