> ## 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.

# Architecture

Model architecture information

## Fields

| Field               | Type                                                                  | Required             | Description                   | Example |
| ------------------- | --------------------------------------------------------------------- | -------------------- | ----------------------------- | ------- |
| `input_modalities`  | List\[[components.InputModality](../components/inputmodality.mdx)]    | :heavy\_check\_mark: | Supported input modalities    |         |
| `instruct_type`     | [Nullable\[components.InstructType\]](../components/instructtype.mdx) | :heavy\_check\_mark: | Instruction format type       | chatml  |
| `modality`          | *Nullable\[str]*                                                      | :heavy\_check\_mark: | Primary modality of the model | text    |
| `output_modalities` | List\[[components.OutputModality](../components/outputmodality.mdx)]  | :heavy\_check\_mark: | Supported output modalities   |         |
| `tokenizer`         | [Nullable\[components.ModelGroup\]](../components/modelgroup.mdx)     | :heavy\_check\_mark: | N/A                           | GPT     |