--- title: "Changes to Create chat completion" method: POST path: "/chat/completions" --- # Changes to Create chat completion `POST /chat/completions` > Every recorded change to this operation, newest first. ## Timeline Changed in 6 of 88 revisions. - **2026-10-26** `06c208dd9567`: 1 info - **2026-10-20** `fbe6e5768509`: 9 info - **2026-10-06** `1a090ea40eb6`: 1 info - **2026-10-06** `487892d3954e`: 6 info - **2026-10-06** `36a5d34b49b8`: 1 breaking, 1 info - **2026-10-05** `7f654af7f94f`: 11 breaking, 24 warning, 26 info ## Changes - **2026-10-26** `06c208dd9567`: 1 info - added the new `gpt-6.1-terra` enum value to the request property `allOf[subschema #2]/model/anyOf[subschema #2]/` - **2026-10-20** `fbe6e5768509`: 9 info - added the new optional request property `allOf[subschema #2]/messages/items/oneOf[subschema #1: Developer message]/content/oneOf[subschema #2: Array of content parts]/items/prompt_cache_breakpoint/ttl` - added the new optional request property `allOf[subschema #2]/messages/items/oneOf[subschema #2: System message]/content/oneOf[subschema #2: Array of content parts]/items/oneOf[subschema #1: Text content part]/prompt_cache_breakpoint/ttl` - added the new optional request property `allOf[subschema #2]/messages/items/oneOf[subschema #3: User message]/content/oneOf[subschema #2: Array of content parts]/items/oneOf[subschema #1: Text content part]/prompt_cache_breakpoint/ttl` - added the new optional request property `allOf[subschema #2]/messages/items/oneOf[subschema #3: User message]/content/oneOf[subschema #2: Array of content parts]/items/oneOf[subschema #2: Image content part]/prompt_cache_breakpoint/ttl` - added the new optional request property `allOf[subschema #2]/messages/items/oneOf[subschema #3: User message]/content/oneOf[subschema #2: Array of content parts]/items/oneOf[subschema #3: Audio content part]/prompt_cache_breakpoint/ttl` - added the new optional request property `allOf[subschema #2]/messages/items/oneOf[subschema #3: User message]/content/oneOf[subschema #2: Array of content parts]/items/oneOf[subschema #4: File content part]/prompt_cache_breakpoint/ttl` - added the new optional request property `allOf[subschema #2]/messages/items/oneOf[subschema #4: Assistant message]/content/anyOf[subschema #1]/oneOf[subschema #2: Array of content parts]/items/oneOf[subschema #1: Text content part]/prompt_cache_breakpoint/ttl` - added the new optional request property `allOf[subschema #2]/messages/items/oneOf[subschema #5: Tool message]/content/oneOf[subschema #2: Array of content parts]/items/oneOf[subschema #1: Text content part]/prompt_cache_breakpoint/ttl` - added the new optional request property `allOf[subschema #2]/prediction/anyOf[subschema #1: Static Content]/content/oneOf[subschema #2: Array of content parts]/items/prompt_cache_breakpoint/ttl` - **2026-10-06** `1a090ea40eb6`: 1 info - the `allOf[#/components/schemas/CreateModelResponseProperties]/allOf[#/components/schemas/ModelResponseProperties]/safety_identifier/anyOf[subschema #1]/` request property's maxLength was increased from `64` to `128` - **2026-10-06** `487892d3954e`: 6 info - added the optional property `error/misalignment/review_target` to the response with the `400` status - added the optional property `error/misalignment/review_target` to the response with the `401` status - added the optional property `error/misalignment/review_target` to the response with the `404` status - added the optional property `error/misalignment/review_target` to the response with the `429` status - added the optional property `error/misalignment/review_target` to the response with the `500` status - added the optional property `error/misalignment/review_target` to the response with the `503` status - **2026-10-06** `36a5d34b49b8`: 1 breaking, 1 info - the response property `choices/items/finish_reason` became optional for the status `200` - added the optional property `choices/items/delta/audio` to the response with the `200` status - **2026-10-05** `7f654af7f94f`: 11 breaking, 24 warning, 26 info - added `#/components/schemas/CreateModelResponseProperties, subschema #2` to the request body `allOf` list - the request's body type changed from `object` to no type - the response property `choices/items/message/function_call` became nullable for the status `200` - the response property `choices/items/message/refusal` became optional for the status `200` - 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` - the `choices/items/logprobs` response's property type changed from `object` to no type for status `200` - the `choices/items/message/tool_calls` response's property type changed from `array` 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 request property `frequency_penalty` - removed the request property `function_call` - removed the request property `functions` - removed the request property `logit_bias` - removed the request property `logprobs` - removed the request property `max_completion_tokens` - removed the request property `max_tokens` - removed the request property `messages` - removed the request property `model` - removed the request property `n` - removed the request property `parallel_tool_calls` - removed the request property `presence_penalty` - removed the request property `response_format` - removed the request property `seed` - removed the request property `service_tier` - removed the request property `stop` - removed the request property `stream` - removed the request property `stream_options` - removed the request property `temperature` - removed the request property `tool_choice` - removed the request property `tools` - removed the request property `top_logprobs` - removed the request property `top_p` - removed the request property `user` - added the media type `text/event-stream` for the response with the status `200` - 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 `403` - added the non-success response with the status `404` - …21 more --- [Operation](https://skmtc.dev/omnistack-sh/apis/openai-api/docs/chat/completions/post.md) - [API](https://skmtc.dev/omnistack-sh/apis/openai-api.md) - [Page](https://skmtc.dev/omnistack-sh/apis/openai-api/changes/chat/completions/post)