---
title: "MessagesOutputConfigFormat"
---

A schema to specify Claude's output format in responses. See [structured outputs](https://platform.claude.com/docs/en/build-with-claude/structured-outputs).


## Fields

| Field                                                                                                | Type                                                                                                 | Required                                                                                             | Description                                                                                          |
| ---------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------- |
| `schema_`                                                                                            | Dict[str, *Nullable[Any]*]                                                                           | :heavy_check_mark:                                                                                   | N/A                                                                                                  |
| `type`                                                                                               | [components.MessagesOutputConfigTypeJSONSchema](../components/messagesoutputconfigtypejsonschema.mdx) | :heavy_check_mark:                                                                                   | N/A                                                                                                  |