extra_body suport

[wdqzdd]

Describe the feature or improvement you are requesting

Additional context

No response

[jsquire]

Hi @wdqzdd. Thank you for reaching out and for your inquiry. This feature request is being tracked by #132, which also has one example of a work-around. If you chose not to use the suggestion there, you would also use the feature using the overload on the client that allows you to drop down to protocol details. A translation of your example would look something like:

var client = new ChatClient("gpt-4.1", "<< YOUR API KEY >>");

// Form the OpenAI payload directly so that we can access the missing tool.           
var rawResponse = await client.CompleteChatAsync(
    BinaryContent.Create(BinaryData.FromString("""
{
  "model": "gpt-4.1",
  "extra_body": {"enable_thinking": true },
  "messages" : [{
      "role": "user",
      "content": "some text value"
    }]      
}
""")));

// The call returns a raw JSON response.  Translate to the associated model so that it is easier to work with.
var completion = ModelReaderWriter.Read<ChatCompletion>(rawResponse.GetRawResponse().Content);
    
foreach (var item in completion.Content)
{
    Console.WriteLine(item.Text);
}

I'm going to close this out as a duplicate.