--- title: "Changes to Cancels a model response with the given ID. Only responses created with\nthe `background` parameter set to `true` can be cancelled. \n[Learn more](/docs/guides/background)." method: POST path: "/responses/{response_id}/cancel" --- # Changes to Cancels a model response with the given ID. Only responses created with the `background` parameter set to `true` can be cancelled. [Learn more](/docs/guides/background). `POST /responses/{response_id}/cancel` > Every recorded change to this endpoint, newest first. ## Timeline Changed in 15 of 86 revisions. - **2026-09-01** `ca86486f9fef` — 1 warning - **2026-09-01** `c192db2d72f9` — 1 warning - **2026-08-29** `959ef977e135` — 2 warning - **2026-08-28** `5c81016c9be7` — 2 info - **2026-08-27** `60c5936f2a2f` — 1 info - **2026-08-26** `c86651eddeec` — 1 info - **2026-08-20** `5de4ab93fa24` — 10 warning - **2026-08-19** `43e6c24649de` — 1 breaking - **2026-08-14** `19962d085c85` — 2 info - **2026-08-14** `6ac2618eefd7` — 1 info - **2026-08-14** `fe3335711e48` — 2 info - **2026-08-13** `fc45a2f64c0a` — 4 warning, 6 info - **2026-08-10** `b8872c4a90ea` — 3 warning - **2026-08-05** `ab0c5306e390` — 20 breaking, 16 warning, 84 info - **2026-05-13** `74cbcf73838f` — 1 info ## Changes - **2026-09-01** `ca86486f9fef` — 1 warning - removed the optional property `allOf[subschema #3]/usage/compute_units` from the response with the `200` status - **2026-09-01** `c192db2d72f9` — 1 warning - added the new `max_messages` enum value to the `allOf[subschema #3]/incomplete_details/anyOf[subschema #1]/reason` response property for the response status `200` - **2026-08-29** `959ef977e135` — 2 warning - removed the optional property `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[#/components/schemas/AdditionalToolsItemParam]/prompt_cache_breakpoint` from the response with the `200` status - removed the optional property `allOf[subschema #3]/output/items/oneOf[#/components/schemas/AdditionalTools]/prompt_cache_breakpoint` from the response with the `200` status - **2026-08-28** `5c81016c9be7` — 2 info - added the optional property `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[#/components/schemas/AdditionalToolsItemParam]/prompt_cache_breakpoint` to the response with the `200` status - added the optional property `allOf[subschema #3]/output/items/oneOf[#/components/schemas/AdditionalTools]/prompt_cache_breakpoint` to the response with the `200` status - **2026-08-27** `60c5936f2a2f` — 1 info - added the optional property `allOf[subschema #3]/usage/compute_units` to the response with the `200` status - **2026-08-26** `c86651eddeec` — 1 info - added the optional property `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #3: Compaction trigger]/id` to the response with the `200` status - **2026-08-20** `5de4ab93fa24` — 10 warning - added the new `gpt-image-2` enum value to the `allOf[#/components/schemas/ResponseProperties]/tools/items/oneOf[subschema #9: Image generation tool]/model/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-image-2` enum value to the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[#/components/schemas/AdditionalToolsItemParam]/tools/items/oneOf[subschema #9: Image generation tool]/model/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-image-2` enum value to the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[#/components/schemas/ToolSearchOutputItemParam]/tools/items/oneOf[subschema #9: Image generation tool]/model/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-image-2` enum value to the `allOf[subschema #3]/output/items/oneOf[#/components/schemas/AdditionalTools]/tools/items/oneOf[subschema #9: Image generation tool]/model/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-image-2` enum value to the `allOf[subschema #3]/output/items/oneOf[#/components/schemas/ToolSearchOutput]/tools/items/oneOf[subschema #9: Image generation tool]/model/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-image-2-2026-04-21` enum value to the `allOf[#/components/schemas/ResponseProperties]/tools/items/oneOf[subschema #9: Image generation tool]/model/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-image-2-2026-04-21` enum value to the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[#/components/schemas/AdditionalToolsItemParam]/tools/items/oneOf[subschema #9: Image generation tool]/model/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-image-2-2026-04-21` enum value to the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[#/components/schemas/ToolSearchOutputItemParam]/tools/items/oneOf[subschema #9: Image generation tool]/model/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-image-2-2026-04-21` enum value to the `allOf[subschema #3]/output/items/oneOf[#/components/schemas/AdditionalTools]/tools/items/oneOf[subschema #9: Image generation tool]/model/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-image-2-2026-04-21` enum value to the `allOf[subschema #3]/output/items/oneOf[#/components/schemas/ToolSearchOutput]/tools/items/oneOf[subschema #9: Image generation tool]/model/anyOf[subschema #2]/` response property for the response status `200` - **2026-08-19** `43e6c24649de` — 1 breaking - the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[subschema #13: Compaction item]/encrypted_content` response property's maxLength was increased from `10485760` to `20971520` for the response status `200` - **2026-08-14** `19962d085c85` — 2 info - removed `subschema #1` from the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[subschema #25: MCP tool call]/error` response property `anyOf` list for the response status `200` - removed `subschema #1` from the `allOf[subschema #3]/output/items/oneOf[subschema #23: MCP tool call]/error` response property `anyOf` list for the response status `200` - **2026-08-14** `6ac2618eefd7` — 1 info - added the non-success response with the status `429` - **2026-08-14** `fe3335711e48` — 2 info - added `#/components/schemas/MCPToolCallError` to the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[subschema #25: MCP tool call]/error` response property `anyOf` list for the response status `200` - added `#/components/schemas/MCPToolCallError` to the `allOf[subschema #3]/output/items/oneOf[subschema #23: MCP tool call]/error` response property `anyOf` list for the response status `200` - **2026-08-13** `fc45a2f64c0a` — 4 warning, 6 info - removed the optional property `allOf[#/components/schemas/ModelResponseProperties]/service_tier` from the response with the `200` status - added the new `gpt-5.5-2026-04-23` enum value to the `allOf[#/components/schemas/ResponseProperties]/model/anyOf[#/components/schemas/ModelIdsShared]/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-5.5-pro` enum value to the `allOf[#/components/schemas/ResponseProperties]/model/anyOf[subschema #2: ResponsesOnlyModel]/` response property for the response status `200` - added the new `gpt-5.5-pro-2026-04-23` enum value to the `allOf[#/components/schemas/ResponseProperties]/model/anyOf[subschema #2: ResponsesOnlyModel]/` response property for the response status `200` - added the optional property `allOf[#/components/schemas/ResponseProperties]/tools/items/oneOf[subschema #5: Web search]/external_web_access` to the response with the `200` status - added the optional property `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[#/components/schemas/AdditionalToolsItemParam]/tools/items/oneOf[subschema #5: Web search]/external_web_access` to the response with the `200` status - added the optional property `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[#/components/schemas/ToolSearchOutputItemParam]/tools/items/oneOf[subschema #5: Web search]/external_web_access` to the response with the `200` status - added the optional property `allOf[subschema #3]/output/items/oneOf[#/components/schemas/AdditionalTools]/tools/items/oneOf[subschema #5: Web search]/external_web_access` to the response with the `200` status - added the optional property `allOf[subschema #3]/output/items/oneOf[#/components/schemas/ToolSearchOutput]/tools/items/oneOf[subschema #5: Web search]/external_web_access` to the response with the `200` status - added the optional property `allOf[subschema #3]/service_tier` to the response with the `200` status - **2026-08-10** `b8872c4a90ea` — 3 warning - added the new `gpt-5.6-cyber` enum value to the `allOf[#/components/schemas/ResponseProperties]/model/anyOf[subschema #2: ResponsesOnlyModel]/` response property for the response status `200` - added the new `gpt-daybreak-blue-latest` enum value to the `allOf[#/components/schemas/ResponseProperties]/model/anyOf[subschema #2: ResponsesOnlyModel]/` response property for the response status `200` - added the new `gpt-daybreak-red-latest` enum value to the `allOf[#/components/schemas/ResponseProperties]/model/anyOf[subschema #2: ResponsesOnlyModel]/` response property for the response status `200` - **2026-08-05** `ab0c5306e390` — 20 breaking, 16 warning, 84 info - the response property `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[subschema #6: Web search tool call]/action/oneOf[subschema #1: Search action]/query` became optional for the status `200` - the response property `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[subschema #8: Function tool call output]/call_id` became optional for the status `200` - the response property `allOf[subschema #3]/output/items/oneOf[#/components/schemas/FunctionToolCallOutputResource]/allOf[subschema #1: Function tool call output]/call_id` became optional for the status `200` - the response property `allOf[subschema #3]/output/items/oneOf[subschema #5: Web search tool call]/action/oneOf[subschema #1: Search action]/query` became optional for the status `200` - response property `allOf[#/components/schemas/ModelResponseProperties]/prompt_cache_key` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `allOf[#/components/schemas/ModelResponseProperties]/safety_identifier` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[subschema #8: Function tool call output]/call_id` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - the `allOf[#/components/schemas/ModelResponseProperties]/safety_identifier` response property's maxLength was unset from `64` for the response status `200` - the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[subschema #8: Function tool call output]/call_id` response property's maxLength was unset from `64` for the response status `200` - the `allOf[#/components/schemas/ResponseProperties]/tools/items/oneOf[subschema #12: Namespace -> subschema #13: Namespace]/description` response property's minLength was decreased from `1` to `0` for the response status `200` - the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[#/components/schemas/ToolSearchOutputItemParam]/tools/items/oneOf[subschema #12: Namespace -> subschema #13: Namespace]/description` response property's minLength was decreased from `1` to `0` for the response status `200` - the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[subschema #8: Function tool call output]/call_id` response property's minLength was decreased from `1` to `0` for the response status `200` - the `allOf[subschema #3]/output/items/oneOf[#/components/schemas/ToolSearchOutput]/tools/items/oneOf[subschema #12: Namespace -> subschema #13: Namespace]/description` response property's minLength was decreased from `1` to `0` for the response status `200` - added `#/components/schemas/AdditionalToolsItemParam` to the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/` response property `oneOf` list for the response status `200` - added `#/components/schemas/CompactionTriggerItemParam, #/components/schemas/ProgramItemParam, #/components/schemas/ProgramOutputItemParam` to the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/` response property `oneOf` list for the response status `200` - added `#/components/schemas/Program, #/components/schemas/ProgramOutput, #/components/schemas/AdditionalTools` to the `allOf[subschema #3]/output/items/` response property `oneOf` list for the response status `200` - added `#/components/schemas/ProgrammaticToolCallingParam` to the `allOf[#/components/schemas/ResponseProperties]/tools/items/` response property `oneOf` list for the response status `200` - added `#/components/schemas/ProgrammaticToolCallingParam` to the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[#/components/schemas/ToolSearchOutputItemParam]/tools/items/` response property `oneOf` list for the response status `200` - added `#/components/schemas/ProgrammaticToolCallingParam` to the `allOf[subschema #3]/output/items/oneOf[#/components/schemas/ToolSearchOutput]/tools/items/` response property `oneOf` list for the response status `200` - added `#/components/schemas/SpecificProgrammaticToolCallingParam` to the `allOf[#/components/schemas/ResponseProperties]/tool_choice` response property `oneOf` list for the response status `200` - removed the optional property `allOf[#/components/schemas/ResponseProperties]/reasoning` from the response with the `200` status - removed the optional property `allOf[#/components/schemas/ResponseProperties]/truncation` from the response with the `200` status - added the new `auto` enum value to the `allOf[#/components/schemas/ResponseProperties]/prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #4: Input file]/detail` response property for the response status `200` - added the new `auto` enum value to the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #1: Input message]/content/oneOf[subschema #2: Input item content list]/items/oneOf[subschema #3: Input file]/detail` response property for the response status `200` - added the new `auto` enum value to the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[subschema #1: Input message]/content/items/oneOf[subschema #3: Input file]/detail` response property for the response status `200` - added the new `auto` enum value to the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[subschema #25: Custom tool call output -> subschema #26: Custom tool call output]/output/oneOf[subschema #2: output content list]/items/oneOf[subschema #3: Input file]/detail` response property for the response status `200` - added the new `auto` enum value to the `allOf[subschema #3]/instructions/anyOf[subschema #1]/oneOf[subschema #2: Input item list]/items/oneOf[subschema #2: Item]/oneOf[subschema #8: Function tool call output]/output/oneOf[subschema #2]/items/oneOf[subschema #3: Input file]/detail` response property for the response status `200` - added the new `auto` enum value to the `allOf[subschema #3]/output/items/oneOf[#/components/schemas/FunctionToolCallOutputResource]/allOf[subschema #1: Function tool call output]/output/oneOf[subschema #2: output content list]/items/oneOf[subschema #3: Input file]/detail` response property for the response status `200` - added the new `auto` enum value to the `allOf[subschema #3]/output/items/oneOf[subschema #25: ResponseCustomToolCallOutputItem -> subschema #28: ResponseCustomToolCallOutputItem]/allOf[subschema #1: Custom tool call output]/output/oneOf[subschema #2: output content list]/items/oneOf[subschema #3: Input file]/detail` response property for the response status `200` - added the new `bio_policy` enum value to the `allOf[subschema #3]/error/anyOf[subschema #1]/code` response property for the response status `200` - added the new `data_residency_mismatch` enum value to the `allOf[subschema #3]/error/anyOf[subschema #1]/code` response property for the response status `200` - added the new `fast` enum value to the `allOf[#/components/schemas/ModelResponseProperties]/service_tier/anyOf[subschema #1]/` response property for the response status `200` - added the new `gpt-5.5` enum value to the `allOf[#/components/schemas/ResponseProperties]/model/anyOf[#/components/schemas/ModelIdsShared]/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-5.6-luna` enum value to the `allOf[#/components/schemas/ResponseProperties]/model/anyOf[#/components/schemas/ModelIdsShared]/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-5.6-sol` enum value to the `allOf[#/components/schemas/ResponseProperties]/model/anyOf[#/components/schemas/ModelIdsShared]/anyOf[subschema #2]/` response property for the response status `200` - added the new `gpt-5.6-terra` enum value to the `allOf[#/components/schemas/ResponseProperties]/model/anyOf[#/components/schemas/ModelIdsShared]/anyOf[subschema #2]/` response property for the response status `200` - added the optional property `allOf[#/components/schemas/ResponseProperties]/prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #2: Input text]/prompt_cache_breakpoint` to the response with the `200` status - added the optional property `allOf[#/components/schemas/ResponseProperties]/prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #3: Input image]/prompt_cache_breakpoint` to the response with the `200` status - added the optional property `allOf[#/components/schemas/ResponseProperties]/prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #4: Input file]/prompt_cache_breakpoint` to the response with the `200` status - added the optional property `allOf[#/components/schemas/ResponseProperties]/tools/items/oneOf[subschema #10: Shell tool -> subschema #11: Shell tool]/allowed_callers` to the response with the `200` status - …80 more - **2026-05-13** `74cbcf73838f` — 1 info - endpoint added --- [Operation](https://skmtc.dev/openai/apis/openapi/docs/responses/:response_id/cancel/post.md) · [API](https://skmtc.dev/openai/apis/openapi.md) · [Page](https://skmtc.dev/openai/apis/openapi/changes/responses/:response_id/cancel/post)