---
title: "Changes to Update chat completion"
method: POST
path: "/chat/completions/{completion_id}"
---

# Changes to Update chat completion

`POST /chat/completions/{completion_id}`

> Every recorded change to this endpoint, newest first.

## Timeline

Changed in 9 of 164 revisions.

- **2026-09-25** `8166b0205067` — 4 info
- **2026-09-01** `ca86486f9fef` — 1 warning
- **2026-08-27** `60c5936f2a2f` — 1 info
- **2026-08-14** `9080adae100c` — 1 info
- **2026-08-14** `fe3335711e48` — 3 info
- **2026-08-05** `ab0c5306e390` — 1 warning, 2 info
- **2026-05-13** `74cbcf73838f` — 17 breaking, 9 info
- **2025-04-29** `6a6c681b1820` — 2 warning, 2 info
- **2025-03-11** `6ab43fe7798e` — 1 info

## Changes

- **2026-09-25** `8166b0205067` — 4 info
  - added the non-success response with the status `400`
  - added the non-success response with the status `404`
  - added the non-success response with the status `429`
  - added the non-success response with the status `500`
- **2026-09-01** `ca86486f9fef` — 1 warning
  - removed the optional property `usage/compute_units` from the response with the `200` status
- **2026-08-27** `60c5936f2a2f` — 1 info
  - added the optional property `usage/compute_units` to the response with the `200` status
- **2026-08-14** `9080adae100c` — 1 info
  - added the optional property `metadata` to the response with the `200` status
- **2026-08-14** `fe3335711e48` — 3 info
  - added the optional property `usage/completion_tokens_details/text_tokens` to the response with the `200` status
  - added the optional property `usage/prompt_tokens_details/image_tokens` to the response with the `200` status
  - added the optional property `usage/prompt_tokens_details/text_tokens` to the response with the `200` status
- **2026-08-05** `ab0c5306e390` — 1 warning, 2 info
  - added the new `fast` enum value to the `service_tier/anyOf[subschema #1]/` response property for the response status `200`
  - added the optional property `moderation` to the response with the `200` status
  - added the optional property `usage/prompt_tokens_details/cache_write_tokens` to the response with the `200` status
- **2026-05-13** `74cbcf73838f` — 17 breaking, 9 info
  - the request property `metadata` became not nullable
  - response property `choices/items/message/content` list-of-types was widened by adding types `null` to media type `application/json` of response `200`
  - response property `choices/items/message/refusal` list-of-types was widened by adding types `null` to media type `application/json` of response `200`
  - response property `service_tier` list-of-types was widened by adding types `null` to media type `application/json` of response `200`
  - added `#/components/schemas/ChatCompletionMessageToolCall, #/components/schemas/ChatCompletionMessageCustomToolCall` to the `choices/items/message/tool_calls/items/` response property `oneOf` list for the response status `200`
  - the `choices/items/logprobs` response's property type changed from `object` to no type for status `200`
  - the `choices/items/message/audio` response's property type changed from `object` to no type for status `200`
  - the `choices/items/message/tool_calls/items/` response's property type changed from `object` to no type for status `200`
  - removed the required property `choices/items/logprobs/content` from the response with the `200` status
  - removed the required property `choices/items/logprobs/refusal` from the response with the `200` status
  - removed the required property `choices/items/message/audio/data` from the response with the `200` status
  - removed the required property `choices/items/message/audio/expires_at` from the response with the `200` status
  - removed the required property `choices/items/message/audio/id` from the response with the `200` status
  - removed the required property `choices/items/message/audio/transcript` from the response with the `200` status
  - removed the required property `choices/items/message/tool_calls/items/function` from the response with the `200` status
  - removed the required property `choices/items/message/tool_calls/items/id` from the response with the `200` status
  - removed the required property `choices/items/message/tool_calls/items/type` from the response with the `200` status
  - request property `metadata` list-of-types was widened by adding types `null` to media type `application/json`
  - added `subschema #1, subschema #2` to the `choices/items/logprobs` response property `anyOf` list for the response status `200`
  - added `subschema #1, subschema #2` to the `choices/items/message/audio` response property `anyOf` list for the response status `200`
  - the `service_tier` response's property default value `auto` was removed for the status `200`
  - response property `system_fingerprint` deprecated
  - added discriminator to `choices/items/message/tool_calls/items/` response property for the response status `200`
  - removed the `auto` enum value from the `service_tier` response property for the response status `200`
  - removed the `default` enum value from the `service_tier` response property for the response status `200`
  - removed the `flex` enum value from the `service_tier` response property for the response status `200`
- **2025-04-29** `6a6c681b1820` — 2 warning, 2 info
  - added the new `auto` enum value to the `service_tier` response property for the response status `200`
  - added the new `flex` enum value to the `service_tier` response property for the response status `200`
  - the `service_tier` response's property default value `auto` was added for the status `200`
  - removed the `scale` enum value from the `service_tier` response property for the response status `200`
- **2025-03-11** `6ab43fe7798e` — 1 info
  - endpoint added

---

[Operation](https://skmtc.dev/openai/apis/openapi/docs/chat/completions/:completion_id/post.md) · [API](https://skmtc.dev/openai/apis/openapi.md) · [Page](https://skmtc.dev/openai/apis/openapi/changes/chat/completions/:completion_id/post)