> ## 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 |
| - | - | - | - | - |
| `clear_at` | [OptionalNullable\[components.AnthropicSystemClearAt\]](../components/anthropicsystemclearat.mdx) | :heavy\_minus\_sign: | N/A | next\_user\_message |
| `content` | [components.MessagesMessageParamContentUnion5](../components/messagesmessageparamcontentunion5.mdx) | :heavy\_check\_mark: | N/A | |
| `output_config` | [OptionalNullable\[components.AnthropicMessageOutputConfig\]](../components/anthropicmessageoutputconfig.mdx) | :heavy\_minus\_sign: | N/A | \{<br />"effort": "low"<br />} |
| `role` | [components.MessagesMessageParamRole](../components/messagesmessageparamrole.mdx) | :heavy\_check\_mark: | N/A | |