bug: gpt-5-nano shown for every openAI

[Halloweedev]

Description

When using any OpenAI Models, in the usage, it returns gpt-5-nano. It is unclear whether Opencode uses the correct model set or gpt-5-nano.

Plugins

No response

OpenCode version

1.1.59

Steps to reproduce

1. Choose any OpenAI model
2. Start a task
3. Check the zen usage -> gpt-5-nano. I connected my ChatGPT subscription account as well to try, same error.

Screenshot and/or share link

No response

Operating System

No response

Terminal

No response

[github-actions]

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This issue might be a duplicate of or related to existing issues. Please check:

• OpenAI provider fails: gpt-5-nano missing from models.dev registry causes ProviderModelNotFoundError #6493: OpenAI provider fails: gpt-5-nano missing from models.dev registry - discusses how gpt-5-nano is hardcoded as the internal 'small model' for OpenAI, which could explain why it appears in usage
• opencode/gpt-5-nano model available in CLI but missing from TUI #9520: opencode/gpt-5-nano model available in CLI but missing from TUI - related issue with gpt-5-nano availability
• The zen site lists GPT-nano as free but it can't be chosen #11593: The zen site lists GPT-nano as free but it can't be chosen - similar model availability issue

The root cause appears to be related to how gpt-5-nano is used internally by OpenCode as the default small model for OpenAI provider.

[Halloweedev]

The issue also opens on using custom models.

i use Kimi K2.5 with a API from NVIDIA and it shows gpt-5-nano in the dashboard