---
title: "Changes to POST /create-chat-completion"
method: POST
path: "/create-chat-completion"
---

# Changes to POST /create-chat-completion

`POST /create-chat-completion`

> Every recorded change to this endpoint, newest first.

## Timeline

Changed in 2 of 28 revisions.

- **2026-04-20** `8ee53928bf31` — 25 breaking, 9 warning, 5 info
- **2026-02-23** `bcff6899fa2a` — 1 info

## Changes

- **2026-04-20** `8ee53928bf31` — 25 breaking, 9 warning, 5 info
  - the `messages/items/oneOf[#/components/schemas/Message]/` response's property type changed from `object` to no type for status `201`
  - the `messages/items/oneOf[#/components/schemas/NodeTransitionMessage]/` response's property type changed from `object` to no type for status `201`
  - the `messages/items/oneOf[#/components/schemas/StateTransitionMessage]/` response's property type changed from `object` to no type for status `201`
  - the `messages/items/oneOf[#/components/schemas/ToolCallInvocationMessage]/` response's property type changed from `object` to no type for status `201`
  - the `messages/items/oneOf[#/components/schemas/ToolCallResultMessage]/` response's property type changed from `object` to no type for status `201`
  - removed the required property `messages/items/oneOf[#/components/schemas/Message]/content` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/Message]/created_timestamp` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/Message]/message_id` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/Message]/role` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/NodeTransitionMessage]/created_timestamp` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/NodeTransitionMessage]/message_id` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/NodeTransitionMessage]/role` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/StateTransitionMessage]/created_timestamp` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/StateTransitionMessage]/message_id` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/StateTransitionMessage]/role` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/ToolCallInvocationMessage]/arguments` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/ToolCallInvocationMessage]/message_id` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/ToolCallInvocationMessage]/name` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/ToolCallInvocationMessage]/role` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/ToolCallInvocationMessage]/tool_call_id` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/ToolCallResultMessage]/content` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/ToolCallResultMessage]/created_timestamp` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/ToolCallResultMessage]/message_id` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/ToolCallResultMessage]/role` from the response with the `201` status
  - removed the required property `messages/items/oneOf[#/components/schemas/ToolCallResultMessage]/tool_call_id` from the response with the `201` status
  - removed the optional property `messages/items/oneOf[#/components/schemas/NodeTransitionMessage]/former_node_id` from the response with the `201` status
  - removed the optional property `messages/items/oneOf[#/components/schemas/NodeTransitionMessage]/former_node_name` from the response with the `201` status
  - removed the optional property `messages/items/oneOf[#/components/schemas/NodeTransitionMessage]/new_node_id` from the response with the `201` status
  - removed the optional property `messages/items/oneOf[#/components/schemas/NodeTransitionMessage]/new_node_name` from the response with the `201` status
  - removed the optional property `messages/items/oneOf[#/components/schemas/StateTransitionMessage]/former_state_name` from the response with the `201` status
  - removed the optional property `messages/items/oneOf[#/components/schemas/StateTransitionMessage]/new_state_name` from the response with the `201` status
  - removed the optional property `messages/items/oneOf[#/components/schemas/ToolCallInvocationMessage]/created_timestamp` from the response with the `201` status
  - removed the optional property `messages/items/oneOf[#/components/schemas/ToolCallInvocationMessage]/thought_signature` from the response with the `201` status
  - removed the optional property `messages/items/oneOf[#/components/schemas/ToolCallResultMessage]/successful` from the response with the `201` status
  - added `#/components/schemas/MessageBase, subschema #2` to the `messages/items/oneOf[#/components/schemas/Message]/` response property `allOf` list for the response status `201`
  - added `#/components/schemas/NodeTransitionMessageBase, subschema #2` to the `messages/items/oneOf[#/components/schemas/NodeTransitionMessage]/` response property `allOf` list for the response status `201`
  - added `#/components/schemas/StateTransitionMessageBase, subschema #2` to the `messages/items/oneOf[#/components/schemas/StateTransitionMessage]/` response property `allOf` list for the response status `201`
  - added `#/components/schemas/ToolCallInvocationMessageBase, subschema #2` to the `messages/items/oneOf[#/components/schemas/ToolCallInvocationMessage]/` response property `allOf` list for the response status `201`
  - added `#/components/schemas/ToolCallResultMessageBase, subschema #2` to the `messages/items/oneOf[#/components/schemas/ToolCallResultMessage]/` response property `allOf` list for the response status `201`
- **2026-02-23** `bcff6899fa2a` — 1 info
  - added the optional property `messages/items/oneOf[#/components/schemas/ToolCallResultMessage]/successful` to the response with the `201` status

---

[Operation](https://skmtc.dev/retellai/apis/retell-sdk/docs/create-chat-completion/post.md) · [API](https://skmtc.dev/retellai/apis/retell-sdk.md) · [Page](https://skmtc.dev/retellai/apis/retell-sdk/changes/create-chat-completion/post)