[QUESTION] How to pass conversation Id parameter to Responses API in .NET?

[Alessio-DAngelo-SL]

How can we help?

Hi, I'm using the latest .NET SDK (OpenAI NuGet package) and I'm trying to use the new Conversations API together with the Responses API. However, in .NET I cannot find any way to pass a conversation ID to the Responses API.
ResponseCreationOptions does not seem to expose a Conversation, ConversationId, or similar property, it looks like the .NET SDK does not currently read or accept a conversation ID parameter for CreateResponseAsync, but I want to confirm.

[Alessio-DAngelo-SL]

In your example you don’t use the conversation ID when creating responses. Should we follow the documentation or the example?

[jsquire]

Hi @Alessio-DAngelo-SL. Thanks for reaching out and we regret that you're experiencing difficulties. The REST API spec used for client generation has not yet integrated the conversations structures for the responses feature. Once the spec is fully upgraded and ingested, the ResponseCreationOptions will support setting the conversation metadata.

In the meantime, you can set the conversation metadata using the JsonPatch feature added in v2.6.0:

var client = new OpenAIResponseClient("gpt-5", "<< YOUR API KEY >>");

var responseOptions = new ResponseCreationOptions
{
    Instructions = "You are Terry Crews and have had 12 cans of Redbull this morning.  You are PUMPED to help any way possible."
};

// Set the conversation id, following the platform docs for information on 
// the right path:  https://platform.openai.com/docs/api-reference/responses/create#responses_create-conversation    
responseOptions.Patch.Set("$.conversation.id"u8, "some-id");

OpenAIResponse rawRresponse = await client.CreateResponseAsync(
    [ResponseItem.CreateUserMessageItem("Tell me a story about cake.")],
    responseOptions);