Codex is literally unusable, i always got prompt_cache_retention is not supported on this model
Nobody has claimed this yet.
- Dominant language
- Rust
- Stars
- 125k
- Forks
- 19.4k
- PR merge metrics
- PR metrics pending
Description
What issue are you seeing?
Always got this everytime sending message,
Error: OpenAI API error (400): {"message":"prompt_cache_retention is not supported on this
model","type":"invalid_request_error","param":"prompt_cache_retention","code":"invalid_parameter"}
Using pi harness with chatgpt subs, using gpt-5.6-luna max
it just start happening today, yesterday seems fine
What steps can reproduce the bug?
use codex like normal, this happen whenever use codex or pi
What is the expected behavior?
should continue to work without throwing those errors
Additional information
No response
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the error by sending a message through Codex or the pi harness, then trace where the OpenAI request includes prompt_cache_retention. Confirm which model configurations reject that parameter and verify that the affected workflow completes without the 400 error.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- api, cli
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Quiet
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100