> ## 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.

# MessagesMessageParam

Anthropic message with OpenRouter extensions

## Fields

| Field          | Type                                                                                                                                    | Required             | Description | Example                        |
| -------------- | --------------------------------------------------------------------------------------------------------------------------------------- | -------------------- | ----------- | ------------------------------ |
| `ClearAt`      | optionalnullable.OptionalNullable\[[components.AnthropicSystemClearAt](../../models/components/anthropicsystemclearat.mdx)]             | :heavy\_minus\_sign: | N/A         | next\_user\_message            |
| `Content`      | [components.MessagesMessageParamContentUnion5](../../models/components/messagesmessageparamcontentunion5.mdx)                           | :heavy\_check\_mark: | N/A         |                                |
| `OutputConfig` | optionalnullable.OptionalNullable\[[components.AnthropicMessageOutputConfig](../../models/components/anthropicmessageoutputconfig.mdx)] | :heavy\_minus\_sign: | N/A         | \{<br />"effort": "low"<br />} |
| `Role`         | [components.MessagesMessageParamRole](../../models/components/messagesmessageparamrole.mdx)                                             | :heavy\_check\_mark: | N/A         |                                |