> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter-d02e98a0-mintlify-a46887cf.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# ModelArchitecture - Go SDK

> ModelArchitecture type definition

<Warning>
  The Go SDK and docs are currently in beta.
  Report issues on [GitHub](https://github.com/OpenRouterTeam/go-sdk/issues).
</Warning>

Model architecture information

## Fields

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