---
title: "Changes to Fork session"
method: POST
path: "/live/sessions/{session_id}/fork"
---

# Changes to Fork session

`POST /live/sessions/{session_id}/fork`

> Every recorded change to this operation, newest first.

## Timeline

Changed in 6 of 88 revisions.

- **2026-10-22** `16f7d1994de2`: 1 info
- **2026-10-08** `0b01d93762e5`: 1 breaking, 3 info
- **2026-10-06** `28bb8391eb37`: 1 breaking, 2 info
- **2026-10-06** `487892d3954e`: 4 info
- **2026-10-06** `e69dcb59acaa`: 1 breaking, 4 info
- **2026-10-05** `7f654af7f94f`: 1 info

## Changes

- **2026-10-22** `16f7d1994de2`: 1 info
  - added the new optional request property `session/delegation/acknowledgement_delay_ms`
- **2026-10-08** `0b01d93762e5`: 1 breaking, 3 info
  - the `session/delegation/responses/tool_choice/oneOf[subschema #2]/` request property type changed from `object` to no type
  - added discriminator to `session/delegation/responses/tool_choice/oneOf[subschema #2]/` request property
  - added `#/components/schemas/LiveAllowedToolsChoiceParam` to the `session/delegation/responses/tool_choice` request property `oneOf` list
  - added `#/components/schemas/LiveFunctionToolChoiceParam, #/components/schemas/LiveMCPToolChoiceParam, #/components/schemas/LiveSpecificFileSearchParam, #/components/schemas/LiveSpecificWebSearchParam, #/components/schemas/LiveSpecificWebSearchPreviewParam, #/components/schemas/LiveSpecificImageGenParam, #/components/schemas/LiveSpecificComputerParam, #/components/schemas/LiveSpecificCodeInterpreterParam, #/components/schemas/LiveSpecificProgrammaticToolCallingParam, #/components/schemas/LiveSpecificFunctionShellParam, #/components/schemas/LiveSpecificCustomToolParam, #/components/schemas/LiveSpecificApplyPatchParam` to the `session/delegation/responses/tool_choice/oneOf[subschema #2]/` request property `oneOf` list
- **2026-10-06** `28bb8391eb37`: 1 breaking, 2 info
  - the `session/delegation/responses/tools/items/oneOf[#/components/schemas/LiveHostedShellToolInputParam]/environment/anyOf[subschema #1]/` request property type changed from `object` to no type
  - added discriminator to `session/delegation/responses/tools/items/oneOf[#/components/schemas/LiveHostedShellToolInputParam]/environment/anyOf[subschema #1]/` request property
  - added `#/components/schemas/LiveHostedShellContainerAutoParam, #/components/schemas/LiveContainerReferenceParam, #/components/schemas/LiveLocalEnvironmentParam` to the `session/delegation/responses/tools/items/oneOf[#/components/schemas/LiveHostedShellToolInputParam]/environment/anyOf[subschema #1]/` request property `oneOf` list
- **2026-10-06** `487892d3954e`: 4 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 `413` 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 `503` status
- **2026-10-06** `e69dcb59acaa`: 1 breaking, 4 info
  - removed `#/components/schemas/LiveFunctionToolChoiceParam, #/components/schemas/LiveMCPToolChoiceParam` from the `session/delegation/responses/tool_choice` request property `oneOf` list
  - the request property `session/delegation/responses/tools/items/oneOf[#/components/schemas/LiveHostedShellToolInputParam]/environment` became optional
  - request property `session/delegation/responses/tools/items/oneOf[#/components/schemas/LiveHostedShellToolInputParam]/environment` list-of-types was widened by adding types `null` to media type `application/json`
  - added `#/components/schemas/LiveMCPToolInputParam, #/components/schemas/LiveCustomToolInputParam, #/components/schemas/LiveNamespaceToolInputParam, #/components/schemas/LiveToolSearchToolInputParam, #/components/schemas/LiveProgrammaticToolInputParam, #/components/schemas/LiveComputerToolInputParam, #/components/schemas/LiveApplyPatchToolInputParam` to the `session/delegation/responses/tools/items/` request property `oneOf` list
  - added `subschema #2` to the `session/delegation/responses/tool_choice` request property `oneOf` list
- **2026-10-05** `7f654af7f94f`: 1 info
  - endpoint added

---

[Operation](https://skmtc.dev/omnistack-sh/apis/openai-api/docs/live/sessions/:session_id/fork/post.md) - [API](https://skmtc.dev/omnistack-sh/apis/openai-api.md) - [Page](https://skmtc.dev/omnistack-sh/apis/openai-api/changes/live/sessions/:session_id/fork/post)