---
title: "Changes to Create a chat completion"
method: POST
path: "/api/chat/completions"
---

# Changes to Create a chat completion

`POST /api/chat/completions`

> Every recorded change to this operation, newest first.

## Timeline

Changed in 7 of 19 revisions.

- **2026-10-21** `c30bcb383ee8`: 8 breaking, 22 info
- **2026-10-02** `b830b79cfd52`: 2 info
- **2026-09-17** `6fa8242da8c2`: 1 warning, 1 info
- **2026-09-12** `22b868ef3f22`: 1 info
- **2026-08-22** `b18c72975097`: 1 warning
- **2026-08-13** `4e064cf81dae`: 1 warning, 13 info
- **2026-07-31** `c26d550029f8`: 6 breaking, 4 warning, 2 info

## Changes

- **2026-10-21** `c30bcb383ee8`: 8 breaking, 22 info
  - request body became required
  - removed the media type `application/json` for the response with the status `401`
  - the response property `error/code` became nullable for the status `400`
  - the response property `error/code` became nullable for the status `404`
  - the response property `error/code` became nullable for the status `424`
  - the response property `error/param` became nullable for the status `400`
  - the response property `error/param` became nullable for the status `404`
  - the response property `error/param` became nullable for the status `424`
  - api operation id `gateway_createChatCompletion` removed and replaced with `createChatCompletion`
  - api tag `Gateway` added
  - api tag `gateway` removed
  - the `exclude_models` request property default value `[]` was added
  - the `exclude_providers` request property default value `[]` was added
  - the `logprobs` request property default value `false` was added
  - the `request_breakdown` request property default value `false` was added
  - the `stream` request property default value `false` was added
  - the `cache_ttl` request property format was generalized from `double` to no format
  - the `frequency_penalty` request property format was generalized from `double` to no format
  - the `max_tokens` request property format was generalized from `double` to no format
  - the `n` request property format was generalized from `double` to no format
  - the `presence_penalty` request property format was generalized from `double` to no format
  - the `temperature` request property format was generalized from `double` to no format
  - the `weight` request property format was generalized from `double` to no format
  - added the media type `text/event-stream` for the response with the status `200`
  - removed `subschema #1, subschema #2` from the `error/code` response property `oneOf` list for the response status `400`
  - removed `subschema #1, subschema #2` from the `error/code` response property `oneOf` list for the response status `404`
  - removed `subschema #1, subschema #2` from the `error/code` response property `oneOf` list for the response status `424`
  - removed `subschema #1, subschema #2` from the `error/param` response property `oneOf` list for the response status `400`
  - removed `subschema #1, subschema #2` from the `error/param` response property `oneOf` list for the response status `404`
  - removed `subschema #1, subschema #2` from the `error/param` response property `oneOf` list for the response status `424`
- **2026-10-02** `b830b79cfd52`: 2 info
  - added the non-success response with the status `403`
  - added the non-success response with the status `404`
- **2026-09-17** `6fa8242da8c2`: 1 warning, 1 info
  - deleted the `header` request parameter `Authorization`
  - the endpoint scheme security `RespanApiKey` was added to the API
- **2026-09-12** `22b868ef3f22`: 1 info
  - api operation id `create-chat-completion` removed and replaced with `gateway_createChatCompletion`
- **2026-08-22** `b18c72975097`: 1 warning
  - the `customer_identifier` request property's maxLength was set to `254`
- **2026-08-13** `4e064cf81dae`: 1 warning, 13 info
  - deleted the `query` request parameter `format`
  - added the new optional `header` request parameter `X-Data-Respan-Params`
  - added the new optional `header` request parameter `X-Respan-Beta`
  - added the new optional `header` request parameter `X-Respan-Route-Provider`
  - 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 `424`
  - added the optional property `usage` to the response with the `200` status
  - added the required property `choices` to the response with the `200` status
  - added the required property `created` to the response with the `200` status
  - added the required property `id` to the response with the `200` status
  - added the required property `model` to the response with the `200` status
  - added the required property `object` to the response with the `200` status
- **2026-07-31** `c26d550029f8`: 6 breaking, 4 warning, 2 info
  - removed the request body
  - removed the required property `choices` from the response with the `200` status
  - removed the required property `created` from the response with the `200` status
  - removed the required property `id` from the response with the `200` status
  - removed the required property `model` from the response with the `200` status
  - removed the required property `object` from the response with the `200` status
  - deleted the `header` request parameter `X-Data-Respan-Params`
  - deleted the `header` request parameter `X-Respan-Beta`
  - deleted the `header` request parameter `X-Respan-Route-Provider`
  - removed the optional property `usage` from the response with the `200` status
  - added the new optional `query` request parameter `format`
  - removed the non-success response with the status `401`

---

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