> ## 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.

# ModelArchitecture

Model architecture information

## Fields

| Field | Type | Required | Description | Example |
| - | - | - | - | - |
| `InputModalities` | \[][components.InputModality](../../models/components/inputmodality.mdx) | :heavy\_check\_mark: | Supported input modalities | |
| `InstructType` | optionalnullable.OptionalNullable\[[components.InstructType](../../models/components/instructtype.mdx)] | :heavy\_minus\_sign: | Instruction format type | chatml |
| `Modality` | `*string` | :heavy\_check\_mark: | Primary modality of the model | text->text |
| `OutputModalities` | \[][components.OutputModality](../../models/components/outputmodality.mdx) | :heavy\_check\_mark: | Supported output modalities | |
| `Tokenizer` | [\*components.ModelGroup](../../models/components/modelgroup.mdx) | :heavy\_minus\_sign: | Tokenizer type used by the model | GPT |