Support for raw JSON objects in system message content

[subham73]

I'm using the OpenAI Go SDK with a custom endpoint that hosts a model. According to the model’s JSON schema, the system message must include a JSON object like this:{ "assistant_name": "Alfred Pennyworth"}
In the Python SDK, I can pass the system message as follows:
{"role": "system", "content": [{"assistant_name": "Alfred Pennyworth"}]}.
And this correctly satisfies the models requirement.

However, in the Go SDK, the current union type for message content only accepts plain strings or an array of text parts. Is there an existing workaround or a suggested solution to pass raw JSON objects in system message

[jacobzim-stl]

The current way to do this is to use param.OverrideObj[T](any) where T is the struct you wish to overwrite.

For example for the ChatCompletionMessageParamUnion

msg := param.OverrideObj[openai.ChatCompletionMessageParamUnion](anyValue),

anyValue can be any type compatible with json.Marshal().

Full disclosure: we're likely going to change the name of param.OverrideObj quite relatively soon before GA. We'd be grateful for any ideas.

[subham73]

@jacobzim-stl Thanks !! Using param.OverrideObj worked for my JSON structure.

sysMsg := param.OverrideObj[openai.ChatCompletionSystemMessageParam](map[string]interface{}{
		"content": []map[string]interface{}{
			{"assistant_name": "Alfred Pennyworth"},
		},
		"role": "system",
	})

However, when using param.OverrideObj with ChatCompletionMessageParamUnion, the output appears as null when marshaled to JSON.
eg.

func main() {
	customData := CustomStruct{
		City: "paradeep",
	}
	systemMsg := param.OverrideObj[openai.ChatCompletionMessageParamUnion](customData)
	userMsg := openai.UserMessage("Hello")

	messages := []openai.ChatCompletionMessageParamUnion{
		systemMsg,
		userMsg,
	}

	jsonBytes, err := json.Marshal(messages)
	fmt.Println(string(jsonBytes))
	fmt.Println(err)
}

output:

[null,{"content":"Hello","role":"user"}]
<nil>

Moreover, using .WithExtraFields. is another way to achieve the same .
eg.

sysmsg := openai.SystemMessage(name)
sysmsg.OfSystem.WithExtraFields(
	map[string]any{
		"content": []any{
			map[string]any{"assistant_name": name},
		},
	},
)

[subham73]

@jacobzim-stl regarding changing the name of param.OverrideObj, it works well for me or maybe CustomObj. But making it more discoverable would be a great option.