> ## 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. # Modality Restrict to models for a modality surface: `text` / `image_output` match output modality, `image` / `audio` match input modality, and `tool_calling` keeps only rows that recorded at least one tool call. Exact dataset — cannot be combined with `category` or `language_type`. ## Example Usage ```go theme={null} import ( "github.com/OpenRouterTeam/go-sdk/models/operations" ) value := operations.ModalityText // Open enum: custom values can be created with a direct type cast custom := operations.Modality("custom_value") ``` ## Values | Name | Value | | --------------------- | ------------- | | `ModalityText` | text | | `ModalityImage` | image | | `ModalityImageOutput` | image\_output | | `ModalityAudio` | audio | | `ModalityToolCalling` | tool\_calling |