2.2.0:

• Add structured reasoning support to OpenAI.V1.Responses, including the Reasoning, ReasoningEffort, and ReasoningSummary types, plus the ServiceTier alias.
• Extend CreateResponse and ResponseObject with reasoning and service_tier fields to round-trip reasoning configuration.

2.1.0:

• Add Item_Input_Reasoning constructor and JSON round-trip test so reasoning traces from tool calls can be echoed back via the Responses API.

2.0.0:

• BREAKING CHANGE: Renamed Item_InputMessage to Item_Input_Message in OpenAI.V1.Responses for consistency with new constructors

  The InputItem data type in the Responses API has been updated to use a consistent naming scheme. If you are using the Responses API, you will need to update your code:

  -- Before (v1.2.0):
  Item_InputMessage { role = ..., content = ..., status = ... }
  
  -- After (v2.0.0):
  Item_Input_Message { role = ..., content = ..., status = ... }
  

• Add support for function tool calls in Responses API

  • New InputItem constructors: Item_Input_Function_Call, Item_Input_Function_Call_Output, Item_Input_Item_Reference
  • Add flattened tool JSON representation for Responses API compatibility
  • Export status constants: statusIncomplete, statusCompleted
  • Export tool choice constants: toolChoiceNoneText, toolChoiceAutoText, toolChoiceRequiredText

• Code quality improvements:

  • Optimize isFunctionField using HashSet for O(1) lookups
  • Simplify unflattenChoice with guards
  • Extract magic strings as named constants

1.2.0:

• /v1/responses: Add support for Responses API
• Add Tool_Web_Search

1.1.1:

• Remove timeout on default ClientEnv
• /v1/chat/completions: Add support for Search
• Fix CreateSpeech JSON instances, add new voices and optional instructions field
• Correct ToJSON of FileSearchResources
• New example app for tool-calling and chat-loop

1.1.0:

• BREAKING CHANGE: Fix details representations for various types [#44] [#45] [#50] [#51]

  A few details-related fields were fixed to match the behavior of the OpenAI API.

• Add FromJSON/ToJSON instances for all types [#42] [#47]

• Add support for reasoning_effort parameter in chat completions

1.0.1:

• Include README
• Include usage example

1.0.0:

• Initial release