--- title: "Changes to Create session" method: POST path: "/realtime/sessions" --- # Changes to Create session `POST /realtime/sessions` > Every recorded change to this operation, newest first. ## Timeline Changed in 20 of 397 revisions. - **2026-10-26** `6f5c52c2ff04`: 3 info - **2026-09-28** `1e2d037e6291`: 4 breaking - **2026-09-23** `52c7140f59a5`: 1 breaking - **2026-08-05** `ab0c5306e390`: 2 warning, 5 info - **2026-07-28** `c7549184dd95`: 2 warning, 2 info - **2026-07-28** `2196f2374732`: 2 warning, 1 info - **2026-07-15** `4065aec90c5d`: 4 info - **2026-07-09** `e0508a503b84`: 4 info - **2026-05-13** `74cbcf73838f`: 11 breaking, 14 warning, 20 info - **2026-05-07** `81aa43d6a9f1`: 1 warning, 1 info - **2026-05-04** `64494d56c425`: 2 breaking - **2026-04-29** `5b98524f8dee`: 1 breaking - **2026-04-10** `7c540cce6eb3`: 12 breaking, 14 warning, 21 info - **2025-03-22** `41844462b873`: 11 breaking, 20 info - **2025-03-11** `6ab43fe7798e`: 1 info - **2025-01-31** `fc164a27fdb9`: 5 info - **2025-01-21** `47138a7dd8b9`: 1 info - **2025-01-21** `0d83ef8a5f65`: 1 breaking - **2025-01-17** `88f3bede7665`: 1 info - **2024-12-18** `8fbbc11fa933`: 1 info ## Changes - **2026-10-26** `6f5c52c2ff04`: 3 info - added the new optional request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #2: Input text]/prompt_cache_breakpoint/ttl` - added the new optional request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #3: Input image]/prompt_cache_breakpoint/ttl` - added the new optional request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #4: Input file]/prompt_cache_breakpoint/ttl` - **2026-09-28** `1e2d037e6291`: 4 breaking - the response property `audio/input/noise_reduction` became nullable for the status `200` - the response property `audio/input/transcription/language` became nullable for the status `200` - the response property `audio/input/turn_detection` became nullable for the status `200` - the response property `turn_detection` became nullable for the status `200` - **2026-09-23** `52c7140f59a5`: 1 breaking - the `modalities` request property type changed from no type to `array` - **2026-08-05** `ab0c5306e390`: 2 warning, 5 info - added the new `gpt-live-transcribe` enum value to the `audio/input/transcription/model/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-transcribe` enum value to the `audio/input/transcription/model/anyOf[subschema #2]/` response property for the response status `200` - added the new optional request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #2: Input text]/prompt_cache_breakpoint` - added the new optional request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #3: Input image]/prompt_cache_breakpoint` - added the new optional request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #4: Input file]/prompt_cache_breakpoint` - added the new `auto` enum value to the request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #4: Input file]/detail` - added the optional property `audio/input/transcription/languages` to the response with the `200` status - **2026-07-28** `c7549184dd95`: 2 warning, 2 info - added the new `gpt-live-transcribe` enum value to the `audio/input/transcription/model/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-transcribe` enum value to the `audio/input/transcription/model/anyOf[subschema #2]/` response property for the response status `200` - added the optional property `audio/input/transcription/keywords` to the response with the `200` status - added the optional property `audio/input/transcription/languages` to the response with the `200` status - **2026-07-28** `2196f2374732`: 2 warning, 1 info - added the new `gpt-live-transcribe` enum value to the `audio/input/transcription/model/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-transcribe` enum value to the `audio/input/transcription/model/anyOf[subschema #2]/` response property for the response status `200` - added the optional property `audio/input/transcription/languages` to the response with the `200` status - **2026-07-15** `4065aec90c5d`: 4 info - added the new optional request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #2: Input text]/prompt_cache_breakpoint` - added the new optional request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #3: Input image]/prompt_cache_breakpoint` - added the new optional request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #4: Input file]/prompt_cache_breakpoint` - added the new `auto` enum value to the request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #4: Input file]/detail` - **2026-07-09** `e0508a503b84`: 4 info - added the new optional request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/anyOf[subschema #2: Input text]/prompt_cache_breakpoint` - added the new optional request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/anyOf[subschema #3: Input image]/prompt_cache_breakpoint` - added the new optional request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/anyOf[subschema #4: Input file]/prompt_cache_breakpoint` - added the new `auto` enum value to the request property `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/anyOf[subschema #4: Input file]/detail` - **2026-05-13** `74cbcf73838f`: 11 breaking, 14 warning, 20 info - added the new required request property `client_secret` - removed `subschema #1, subschema #2` from the `voice` request property `anyOf` list - removed the enum value `g711_alaw` of the request property `input_audio_format` - removed the enum value `g711_alaw` of the request property `output_audio_format` - removed the enum value `g711_ulaw` of the request property `input_audio_format` - removed the enum value `g711_ulaw` of the request property `output_audio_format` - removed the enum value `pcm16` of the request property `input_audio_format` - removed the enum value `pcm16` of the request property `output_audio_format` - removed the enum value `semantic_vad` of the request property `turn_detection/type` - removed the enum value `server_vad` of the request property `turn_detection/type` - removed the required property `client_secret` from the response with the `200` status - removed the request property `input_audio_noise_reduction` - removed the request property `input_audio_transcription/language` - removed the request property `input_audio_transcription/prompt` - removed the request property `model` - removed the request property `turn_detection/create_response` - removed the request property `turn_detection/eagerness` - removed the request property `turn_detection/interrupt_response` - removed the optional property `input_audio_format` from the response with the `200` status - removed the optional property `input_audio_transcription` from the response with the `200` status - removed the optional property `max_response_output_tokens` from the response with the `200` status - removed the optional property `modalities` from the response with the `200` status - removed the optional property `output_audio_format` from the response with the `200` status - removed the optional property `temperature` from the response with the `200` status - removed the optional property `voice` from the response with the `200` status - added the new optional request property `prompt` - added the new optional request property `speed` - added the new optional request property `tracing` - added the new optional request property `truncation` - added `#/components/schemas/VoiceIdsShared, subschema #2` to the `voice` request property `anyOf` list - the `` request property default value `text, audio` was removed - the `input_audio_format` request property default value `pcm16` was removed - the `output_audio_format` request property default value `pcm16` was removed - the `temperature` request property default value `0.8` was removed - the `tool_choice` request property default value `auto` was removed - the `type` request property default value `server_vad` was removed - added the optional property `audio` to the response with the `200` status - added the optional property `expires_at` to the response with the `200` status - added the optional property `id` to the response with the `200` status - added the optional property `include` to the response with the `200` status - …5 more - **2026-05-07** `81aa43d6a9f1`: 1 warning, 1 info - added the new `gpt-realtime-whisper` enum value to the `audio/input/transcription/model/anyOf[subschema #2]/` response property for the response status `200` - added the optional property `audio/input/transcription/delay` to the response with the `200` status - **2026-05-04** `64494d56c425`: 2 breaking - the `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/anyOf[subschema #3: Input image]/image_url/anyOf[subschema #1]/` request property format changed from no format to `uri` - the `prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/anyOf[subschema #4: Input file]/file_url` request property format changed from no format to `uri` - **2026-04-29** `5b98524f8dee`: 1 breaking - the `client_secret/expires_at` request property format changed from no format to `unixtime` - **2026-04-10** `7c540cce6eb3`: 12 breaking, 14 warning, 21 info - added the new required request property `client_secret` - removed `subschema #1, subschema #2` from the `voice` request property `anyOf` list - removed the enum value `g711_alaw` of the request property `input_audio_format` - removed the enum value `g711_alaw` of the request property `output_audio_format` - removed the enum value `g711_ulaw` of the request property `input_audio_format` - removed the enum value `g711_ulaw` of the request property `output_audio_format` - removed the enum value `pcm16` of the request property `input_audio_format` - removed the enum value `pcm16` of the request property `output_audio_format` - removed the enum value `semantic_vad` of the request property `turn_detection/type` - removed the enum value `server_vad` of the request property `turn_detection/type` - removed `subschema #1, subschema #2` from the `max_response_output_tokens` request property `oneOf` list - removed the required property `client_secret` from the response with the `200` status - removed the request property `input_audio_noise_reduction` - removed the request property `input_audio_transcription/language` - removed the request property `input_audio_transcription/prompt` - removed the request property `model` - removed the request property `turn_detection/create_response` - removed the request property `turn_detection/eagerness` - removed the request property `turn_detection/interrupt_response` - removed the optional property `input_audio_format` from the response with the `200` status - removed the optional property `input_audio_transcription` from the response with the `200` status - removed the optional property `max_response_output_tokens` from the response with the `200` status - removed the optional property `modalities` from the response with the `200` status - removed the optional property `output_audio_format` from the response with the `200` status - removed the optional property `temperature` from the response with the `200` status - removed the optional property `voice` from the response with the `200` status - added the new optional request property `prompt` - added the new optional request property `speed` - added the new optional request property `tracing` - added the new optional request property `truncation` - added `#/components/schemas/VoiceIdsShared, subschema #2` to the `voice` request property `anyOf` list - added `subschema #1, subschema #2` to the `max_response_output_tokens` request property `anyOf` list - the `` request property default value `text, audio` was removed - the `input_audio_format` request property default value `pcm16` was removed - the `output_audio_format` request property default value `pcm16` was removed - the `temperature` request property default value `0.8` was removed - the `tool_choice` request property default value `auto` was removed - the `type` request property default value `server_vad` was removed - added the optional property `audio` to the response with the `200` status - added the optional property `expires_at` to the response with the `200` status - …7 more - **2025-03-22** `41844462b873`: 11 breaking, 20 info - request property `turn_detection/type` was restricted to a list of enum values - removed the enum value `alloy` of the request property `voice` - removed the enum value `ash` of the request property `voice` - removed the enum value `ballad` of the request property `voice` - removed the enum value `coral` of the request property `voice` - removed the enum value `echo` of the request property `voice` - removed the enum value `sage` of the request property `voice` - removed the enum value `shimmer` of the request property `voice` - removed the enum value `verse` of the request property `voice` - the `voice` request property type changed from `string` to no type - the `voice` response's property type changed from `string` to no type for status `200` - added the new optional request property `input_audio_noise_reduction` - added the new optional request property `turn_detection/eagerness` - added `subschema #1, subschema #2` to the `voice` request property `anyOf` list - the `` request property default value `text, audio` was added - the `input_audio_format` request property default value `pcm16` was added - the `output_audio_format` request property default value `pcm16` was added - the `temperature` request property default value `0.8` was added - the `tool_choice` request property default value `auto` was added - the `type` request property default value `server_vad` was added - added the new `semantic_vad` enum value to the request property `turn_detection/type` - added the new `server_vad` enum value to the request property `turn_detection/type` - added `subschema #1, subschema #2` to the `voice` response property `anyOf` list for the response status `200` - removed the `alloy` enum value from the `voice` response property for the response status `200` - removed the `ash` enum value from the `voice` response property for the response status `200` - removed the `ballad` enum value from the `voice` response property for the response status `200` - removed the `coral` enum value from the `voice` response property for the response status `200` - removed the `echo` enum value from the `voice` response property for the response status `200` - removed the `sage` enum value from the `voice` response property for the response status `200` - removed the `shimmer` enum value from the `voice` response property for the response status `200` - removed the `verse` enum value from the `voice` response property for the response status `200` - **2025-03-11** `6ab43fe7798e`: 1 info - added the new optional request property `turn_detection/interrupt_response` - **2025-01-31** `fc164a27fdb9`: 5 info - added the new optional request property `input_audio_transcription/language` - added the new optional request property `input_audio_transcription/prompt` - the response property `client_secret` became required for the status `200` - the response property `client_secret/expires_at` became required for the status `200` - the response property `client_secret/value` became required for the status `200` - **2025-01-21** `47138a7dd8b9`: 1 info - the request property `model` became optional - **2025-01-21** `0d83ef8a5f65`: 1 breaking - the request property `model` became required - **2025-01-17** `88f3bede7665`: 1 info - the request property `model` became optional - **2024-12-18** `8fbbc11fa933`: 1 info - endpoint added --- [Operation](https://skmtc.dev/openai/apis/openapi/docs/realtime/sessions/post.md) - [API](https://skmtc.dev/openai/apis/openapi.md) - [Page](https://skmtc.dev/openai/apis/openapi/changes/realtime/sessions/post)