---
title: "Changes to Create an Anthropic message"
method: POST
path: "/api/anthropic/v1/messages"
---

# Changes to Create an Anthropic message

`POST /api/anthropic/v1/messages`

> Every recorded change to this operation, newest first.

## Timeline

Changed in 6 of 19 revisions.

- **2026-10-21** `c30bcb383ee8`: 2 breaking, 4 info
- **2026-10-02** `b830b79cfd52`: 3 info
- **2026-09-12** `22b868ef3f22`: 1 info
- **2026-08-22** `b18c72975097`: 1 warning
- **2026-08-13** `4e064cf81dae`: 2 breaking, 2 warning, 9 info
- **2026-07-31** `c26d550029f8`: 1 info

## Changes

- **2026-10-21** `c30bcb383ee8`: 2 breaking, 4 info
  - request body became required
  - the `messages` request property's minItems was increased to `1`
  - api operation id `anthropicGateway_api_anthropic_v1_messages_create` removed and replaced with `api_anthropic_v1_messages_create`
  - api tag `Anthropic Gateway` added
  - api tag `anthropicGateway` removed
  - added the media type `text/event-stream` for the response with the status `200`
- **2026-10-02** `b830b79cfd52`: 3 info
  - the `header` request parameter `anthropic-version` became optional
  - added the non-success response with the status `403`
  - removed the non-success response with the status `401`
- **2026-09-12** `22b868ef3f22`: 1 info
  - api operation id `api-anthropic-v-1-messages-create` removed and replaced with `anthropicGateway_api_anthropic_v1_messages_create`
- **2026-08-22** `b18c72975097`: 1 warning
  - the `max_tokens` request property's min was set to `1.00`
- **2026-08-13** `4e064cf81dae`: 2 breaking, 2 warning, 9 info
  - added the new required `header` request parameter `anthropic-version`
  - added the new required `header` request parameter `x-api-key`
  - deleted the `header` request parameter `Authorization`
  - deleted the `query` request parameter `format`
  - api tag `anthropicGateway` added
  - api tag `proxy` removed
  - added the new optional `header` request parameter `anthropic-beta`
  - added optional request body
  - added the non-success response with the status `400`
  - added the non-success response with the status `401`
  - added the non-success response with the status `402`
  - added the non-success response with the status `424`
  - added the non-success response with the status `429`
- **2026-07-31** `c26d550029f8`: 1 info
  - endpoint added

---

[Operation](https://skmtc.dev/keywordsai/apis/respan-api/docs/api/anthropic/v1/messages/post.md) - [API](https://skmtc.dev/keywordsai/apis/respan-api.md) - [Page](https://skmtc.dev/keywordsai/apis/respan-api/changes/api/anthropic/v1/messages/post)