Update OpenAI Provider to allow GPT-5 usage #3923
Description
Please explain the motivation behind the feature request.
GPT-5 is currently unusable, as it uses the max_completion_tokens config, similiar to oX models, but Goose's provider logic does not capture this.
Describe the solution you'd like
Update the is_ox_model flag in providers/openai.rs to include GPT-5 models.
Describe alternatives you've considered
None.
Additional context
None.
- I have verified this does not duplicate an existing feature request