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

# Changes to Create chat completions

`POST /v1/private/chat/completions`

> Every recorded change to this operation, newest first.

## Timeline

Changed in 2 of 82 revisions.

- **2026-10-08** `bf800f7c6542`: 4 info
- **2026-09-10** `78a7cbc1232c`: 42 warning, 42 info

## Changes

- **2026-10-08** `bf800f7c6542`: 4 info
  - added the new optional request property `promptCacheKey`
  - added the new optional request property `promptCacheOptions`
  - added the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/usage/promptTokensDetails/cacheWriteTokens` to the response with the `200` status (media type: text/event-stream)
  - added the optional property `usage/promptTokensDetails/cacheWriteTokens` to the response with the `200` status (media type: application/json)
- **2026-09-10** `78a7cbc1232c`: 42 warning, 42 info
  - removed the request property `frequency_penalty`
  - removed the request property `function_call`
  - removed the request property `logit_bias`
  - removed the request property `max_completion_tokens`
  - removed the request property `max_tokens`
  - removed the request property `parallel_tool_calls`
  - removed the request property `presence_penalty`
  - removed the request property `reasoning_effort`
  - removed the request property `response_format`
  - removed the request property `service_tier`
  - removed the request property `stream_options`
  - removed the request property `tool_choice`
  - removed the request property `top_logprobs`
  - removed the request property `top_p`
  - removed the optional property `choices/items/delta/function_call` from the response with the `200` status (media type: application/json)
  - removed the optional property `choices/items/delta/reasoning_content` from the response with the `200` status (media type: application/json)
  - removed the optional property `choices/items/delta/tool_calls` from the response with the `200` status (media type: application/json)
  - removed the optional property `choices/items/finish_reason` from the response with the `200` status (media type: application/json)
  - removed the optional property `choices/items/message/function_call` from the response with the `200` status (media type: application/json)
  - removed the optional property `choices/items/message/reasoning_content` from the response with the `200` status (media type: application/json)
  - removed the optional property `choices/items/message/tool_calls` from the response with the `200` status (media type: application/json)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/choices/items/delta/function_call` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/choices/items/delta/reasoning_content` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/choices/items/delta/tool_calls` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/choices/items/finish_reason` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/choices/items/message/function_call` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/choices/items/message/reasoning_content` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/choices/items/message/tool_calls` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/service_tier` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/system_fingerprint` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/usage/completion_tokens` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/usage/completion_tokens_details` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/usage/prompt_tokens` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/usage/prompt_tokens_details` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `items/anyOf[#/components/schemas/ChatCompletionResponse]/usage/total_tokens` from the response with the `200` status (media type: text/event-stream)
  - removed the optional property `service_tier` from the response with the `200` status (media type: application/json)
  - removed the optional property `system_fingerprint` from the response with the `200` status (media type: application/json)
  - removed the optional property `usage/completion_tokens` from the response with the `200` status (media type: application/json)
  - removed the optional property `usage/completion_tokens_details` from the response with the `200` status (media type: application/json)
  - removed the optional property `usage/prompt_tokens` from the response with the `200` status (media type: application/json)
  - …44 more

---

[Operation](https://skmtc.dev/comet-ml/apis/opik-rest-api/docs/v1/private/chat/completions/post.md) - [API](https://skmtc.dev/comet-ml/apis/opik-rest-api.md) - [Page](https://skmtc.dev/comet-ml/apis/opik-rest-api/changes/v1/private/chat/completions/post)