> ## 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.

# ChatFunctionToolFunction - Go SDK

> ChatFunctionToolFunction 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.ChatContentCacheControl](/client-sdks/go/api-reference/models/chatcontentcachecontrol)                 | :heavy\_minus\_sign: | Cache control for the content part   | `{"ttl": "5m","type": "ephemeral"}`                                                                                                                                                                                                                              |
| `Function`     | [components.ChatFunctionToolFunctionFunction](/client-sdks/go/api-reference/models/chatfunctiontoolfunctionfunction) | :heavy\_check\_mark: | Function definition for tool calling | `{"description": "Get the current weather for a location","name": "get_weather","parameters": {"properties": {"location": {"description": "City name","type": "string"}`<br />},<br />"required": \[<br />"location"<br />],<br />"type": "object"<br />}<br />} |
| `Type`         | [components.ChatFunctionToolType](/client-sdks/go/api-reference/models/chatfunctiontooltype)                         | :heavy\_check\_mark: | N/A                                  |                                                                                                                                                                                                                                                                  |