Short answer
review_model is the model Codex uses for code review workflows. model_reasoning_effort controls reasoning strength for models that support the Responses API.
Both fields can affect quality, speed, and usage cost. Higher reasoning settings are better for complex tasks, but they can consume more.
Field relationships
Recommended config
Common mistakes
- Thinking
review_modelreplaces the main model for all tasks. - Treating reasoning effort as a temperature setting.
- Using a model ID unsupported by the current provider.
- Using the highest reasoning effort for every task.
- Looking only at model names without checking actual usage and result quality.
About BetterToken
Different models and reasoning settings affect usage. BetterToken usage records help you compare input, output, and cost across real tasks. Copy model IDs from the GPT Key group so the current provider can recognize them.Related docs
- How to configure Codex CLI config.toml
- What are model_provider, base_url, and wire_api?
- Codex BetterToken setup guide
- What are Codex CLI sandbox and approval modes?