> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter-d02e98a0-mintlify-7021d5f4.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# MessagesMessageParam - Go SDK

> MessagesMessageParam type definition

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

Anthropic message with OpenRouter extensions

## Fields

| Field     | Type                                                                                                                   | Required             | Description |
| --------- | ---------------------------------------------------------------------------------------------------------------------- | -------------------- | ----------- |
| `Content` | [components.MessagesMessageParamContentUnion5](/client-sdks/go/api-reference/models/messagesmessageparamcontentunion5) | :heavy\_check\_mark: | N/A         |
| `Role`    | [components.MessagesMessageParamRole](/client-sdks/go/api-reference/models/messagesmessageparamrole)                   | :heavy\_check\_mark: | N/A         |