> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# ModelReasoning

Reasoning effort configuration. Omitted for non-reasoning models and dynamic router models.

## Fields

| Field                 | Type                                                                               | Required             | Description                                                                                                                                                        | Example |
| --------------------- | ---------------------------------------------------------------------------------- | -------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------- |
| `default_effort`      | [OptionalNullable\[components.DefaultEffort\]](../components/defaulteffort.mdx)    | :heavy\_minus\_sign: | N/A                                                                                                                                                                | medium  |
| `default_enabled`     | *Optional\[bool]*                                                                  | :heavy\_minus\_sign: | Default reasoning enabled state when the client does not set `reasoning.enabled`.                                                                                  |         |
| `mandatory`           | *bool*                                                                             | :heavy\_check\_mark: | When true, reasoning cannot be disabled and effort "none" is rejected.                                                                                             |         |
| `supported_efforts`   | List\[[Nullable\[components.ReasoningEffort\]](../components/reasoningeffort.mdx)] | :heavy\_minus\_sign: | Allowed reasoning effort values for this model, in descending effort order (highest first). Null means no allowlist — all gateway effort values are accepted.      |         |
| `supports_max_tokens` | *Optional\[bool]*                                                                  | :heavy\_minus\_sign: | Present and `true` when the model accepts `reasoning.max_tokens` in requests (Anthropic-style) instead of or in addition to `reasoning.effort`. Omitted otherwise. |         |