---
title: "Changes to Create Chat Completion"
method: POST
path: "/v1/chat/completions"
---

# Changes to Create Chat Completion

`POST /v1/chat/completions`

> Every recorded change to this operation, newest first.

## Timeline

Changed in 7 of 64 revisions.

- **2026-10-23** `a99a7b2a5444`: 2 warning, 1 info
- **2026-10-15** `b6eb5ddf06a9`: 2 info
- **2026-09-29** `8c9311580b72`: 3 breaking, 15 info
- **2026-09-28** `1efa21f7aeb8`: 1 info
- **2026-09-22** `aea928d034f7`: 1 info
- **2026-09-21** `59e078d20686`: 2 info
- **2026-09-04** `215e05fb8aa5`: 1 info

## Changes

- **2026-10-23** `a99a7b2a5444`: 2 warning, 1 info
  - deleted the `header` request parameter `X-Model-Endpoint-Id`
  - deleted the `header` request parameter `x-model-endpoint-access-token`
  - added the new optional request property `disable_thinking`
- **2026-10-15** `b6eb5ddf06a9`: 2 info
  - request property `stream` list-of-types was widened by adding types `null` to media type `application/json`
  - added the optional property `choices/items/message/function_call` to the response with the `200` status
- **2026-09-29** `8c9311580b72`: 3 breaking, 15 info
  - the `header` request parameter `X-Trajectory-Id` became required
  - `header` request parameter `X-Trajectory-Id` list-of-types was narrowed by removing types `null`
  - for the `header` request parameter `X-Trajectory-Id`, the minLength was increased from `0` to `1`
  - for the `header` request parameter `X-Trajectory-Id`, the type was generalized from no type to `string`
  - added the optional property `choices/items/delta/tool_calls/anyOf[subschema #1]/items/function` to the response with the `200` status (media type: text/event-stream)
  - added the optional property `choices/items/delta/tool_calls/anyOf[subschema #1]/items/id` to the response with the `200` status (media type: text/event-stream)
  - added the optional property `choices/items/delta/tool_calls/anyOf[subschema #1]/items/type` to the response with the `200` status (media type: text/event-stream)
  - added the optional property `choices/items/logprobs` to the response with the `200` status (media type: application/json)
  - added the optional property `choices/items/message/tool_calls` to the response with the `200` status (media type: application/json)
  - added the optional property `usage/anyOf[subschema #1: Usage]/completion_tokens_details` to the response with the `200` status (media type: application/json)
  - added the optional property `usage/anyOf[subschema #1: Usage]/completion_tokens_details` to the response with the `200` status (media type: text/event-stream)
  - added the optional property `usage/anyOf[subschema #1: Usage]/prompt_tokens_details` to the response with the `200` status (media type: application/json)
  - added the optional property `usage/anyOf[subschema #1: Usage]/prompt_tokens_details` to the response with the `200` status (media type: text/event-stream)
  - added `#/components/schemas/ChatCompletionChoiceLogprobs` to the `choices/items/logprobs` response property `anyOf` list for the response status `200` (media type: text/event-stream)
  - added `#/components/schemas/ChatCompletionChunkFunction` to the `choices/items/delta/function_call` response property `anyOf` list for the response status `200` (media type: text/event-stream)
  - removed `subschema #1` from the `choices/items/delta/function_call` response property `anyOf` list for the response status `200` (media type: text/event-stream)
  - removed `subschema #1` from the `choices/items/logprobs` response property `anyOf` list for the response status `200` (media type: text/event-stream)
  - added the required property `choices/items/delta/tool_calls/anyOf[subschema #1]/items/index` to the response with the `200` status (media type: text/event-stream)
- **2026-09-28** `1efa21f7aeb8`: 1 info
  - added the new optional `header` request parameter `Idempotency-Key`
- **2026-09-22** `aea928d034f7`: 1 info
  - added the new optional `header` request parameter `x-model-endpoint-access-token`
- **2026-09-21** `59e078d20686`: 2 info
  - added the new optional `header` request parameter `X-Model-Endpoint-Id`
  - added the new optional `header` request parameter `X-Trajectory-Id`
- **2026-09-04** `215e05fb8aa5`: 1 info
  - added the media type `text/event-stream` for the response with the status `200`

---

[Operation](https://skmtc.dev/trajectory/apis/trajectory-api/docs/v1/chat/completions/post.md) - [API](https://skmtc.dev/trajectory/apis/trajectory-api.md) - [Page](https://skmtc.dev/trajectory/apis/trajectory-api/changes/v1/chat/completions/post)