# OpenAI
OpenAI uses API-key auth (`provider = "openai"`, `auth = "api-key"`). For shared concepts such as credential storage and model selection, see [authentication and models](/authentication-and-models).
## Sign in
```text
/login openai
```
`/login openai` opens a masked API-key entry box in the [interactive TUI](/interactive-tui). Credentials are stored in the native OS credential store, not in config or transcripts.
## Sign out
```text
/logout openai
```
`/logout openai` deletes the stored OpenAI API key. If an environment override is still present, the provider stays available.
## Environment override
```bash
OPENAI_API_KEY=...
```
Environment variables are CI/development escape hatches and override stored credentials. For normal interactive setup, prefer `/login`.
## Models
OpenAI can refresh its provider model list with `/refresh-model-list openai`. Switch to an OpenAI model with:
```text
/model openai/gpt-5.6-sol
```
Or from the CLI, which also updates the persistent default:
```bash
rho --provider openai --auth api-key --model gpt-5.6-sol
```
## Notes
- OpenAI API-key requests use the Chat Completions API and do not currently send a [reasoning](/configuration#reasoning-options) configuration.
- Pricing-sensitive models such as `openai/gpt-5.6-sol` use safer effective context windows below their advertised maximums to avoid long-context pricing thresholds.