Model metadata for `gpt-5-codex` not found. Defaulting to fallback metadata; this can degrade performance and cause issues
Resolved 💬 20 comments Opened Feb 18, 2026 by hashem-reyi Closed Feb 23, 2026
💡 Likely answer: A maintainer (etraut-openai, contributor)
responded on this thread — see the highlighted reply below.
What version of Codex CLI is running?
0.104.0
What subscription do you have?
custom provider
Which model were you using?
gpt 5.1 codex
What platform is your computer?
Windows 11
What terminal emulator and version are you using (if applicable)?
_No response_
What issue are you seeing?
Model metadata not found. Defaulting to fallback metadata; this can degrade performance and cause issues
What steps can reproduce the bug?
Model metadata not found. Defaulting to fallback metadata; this can degrade performance and cause issues
What is the expected behavior?
_No response_
Additional information
_No response_
20 Comments
Can you provide more details? I'm not sure what "OCA custom provider" means. Are you saying that you are defining a custom model provider? If so, can you share repro steps including any required config settings?
Looks like this error message is introduced in https://github.com/openai/codex/pull/11690. I also encountered this together with some error in #12114 when using OpenRouter.
Getting same error on OCA (Oracle Code Assist) model provider.
This bug report labels
windows-osbut I'm on macOS.codex --oss:⚠ Model metadata forgpt-oss:20bnot found. Defaulting to fallback metadata; this can degrade performance and cause issues.Then after several commands it just stops working without any error message (perhaps context issue). Example on real small task:
No "Working" anymore, it is stopped and nothing is produced. Everything is the same, but
rust-v0.98.0was working OK.@maheshvipersonal-cloud so what's the fix in the config for OCA?
Or for gpt-oss users…
So now it will degrade performance of non-OAI models and providers unless OpenAI server providing the metadata?
I did that and it just gets overwritten when you launch. I also tried setting the profile model_catalog_json to a file with information similar to models_cache.json and it won't load it. Doesn't seem to be much documentation explaining that file either, but in the interim it seems that this warning happens for gpt-oss users and in most cases I see errors around disconnected streams now from gpt-oss model, so effectively it seems broken.
I can't find folder "./codex", and I also can't find models_cache.json in ~/.codex fold. Could you tell me the full path?
@riversedge, the
model_catalog_jsonconfig key was added after the0.104.0release, which probably explains why it's not working for you. This functionality will be included in0.105.0. If you want to try it out now, you can install the latest alpha (0.105.0-alpha.16).@wangbin77 the .codex folder should be inside your user profile folder.
@vm-code01 where is models_cache.json
@coder543, you can fix the warning by using a profile like this:
codex --profile lmstudiohome/USERNAME/.codex/config.toml
/home/USERNAME/.codex/model-catalogs/lmstudio-oss20b.json (note the lowered max context because of RAM contrains)
EDIT: Thanks to @coder543. The full model catalog is at https://github.com/openai/codex/blob/main/codex-rs/core/models.json
---
If you, like me, struggled to find the original model_catalog.json to edit, here's the full one as of 2026-03-03:
<details>
<summary>Full model catalog</summary>
</details>
---
To get this, I had to
chatgpt.com/backend-api/codex/responses. Copy the Authorization header.curl https://chatgpt.com/backend-api/codex/models?client_version=0.107.0 -H "Authorization: [paste here]"I hope this was simpler.
@SuperKenVery is that different from this? https://github.com/openai/codex/blob/main/codex-rs/core/models.json
I’ve also found that if you only override the model catalog in a profile, then you don’t need to worry about the original data. The cloud models will work when you’re not in a profile that overrides the model catalog.
@coder543 Oh, they are indeed the same. I was too stupid.
It's about codex working with custom providers, this helps others and is relevant to codex. Why delete it?
On my personal MacBook Pro M1 Pro, I deployed the qwen2.5-coder:7b model using Ollama. Then, after running ollama launch codex and selecting the locally deployed qwen2.5-coder:7b model, I received the message:
“Model metadata for qwen2.5-coder:7b not found. Defaulting to fallback metadata; this can degrade performance and cause issues.”
@DDxxgg ollama is not configuring things correctly. Not a codex issue. File a bug with Ollama.
It moved to here https://github.com/openai/codex/blob/main/codex-rs/models-manager/models.json