> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter-d02e98a0-mintlify-5b6e02fd.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# AnthropicDocumentBlockParam - Go SDK

> AnthropicDocumentBlockParam type definition

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

## Fields

| Field          | Type                                                                                                                                                             | Required             | Description                                                                                                                                                                                                 | Example                 |
| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------- |
| `CacheControl` | [\*components.AnthropicCacheControlDirective](/client-sdks/go/api-reference/models/anthropiccachecontroldirective)                                               | :heavy\_minus\_sign: | Enable automatic prompt caching. When set at the top level, the system automatically applies cache breakpoints to the last cacheable block in the request. Currently supported for Anthropic Claude models. | `{"type": "ephemeral"}` |
| `Citations`    | optionalnullable.OptionalNullable\[[components.AnthropicDocumentBlockParamCitations](/client-sdks/go/api-reference/models/anthropicdocumentblockparamcitations)] | :heavy\_minus\_sign: | N/A                                                                                                                                                                                                         |                         |
| `Context`      | optionalnullable.OptionalNullable\[`string`]                                                                                                                     | :heavy\_minus\_sign: | N/A                                                                                                                                                                                                         |                         |
| `Source`       | [components.AnthropicDocumentBlockParamSourceUnion](/client-sdks/go/api-reference/models/anthropicdocumentblockparamsourceunion)                                 | :heavy\_check\_mark: | N/A                                                                                                                                                                                                         |                         |
| `Title`        | optionalnullable.OptionalNullable\[`string`]                                                                                                                     | :heavy\_minus\_sign: | N/A                                                                                                                                                                                                         |                         |
| `Type`         | [components.TypeDocument](/client-sdks/go/api-reference/models/typedocument)                                                                                     | :heavy\_check\_mark: | N/A                                                                                                                                                                                                         |                         |