Discord ChatGPT机器人适配gpt-3.5-turbo时API报错及解决

约一周前开发了一个将ChatGPT接入Discord服务器的机器人，OpenAI更新模型后，尝试适配gpt-3.5-turbo时运行ask命令出现报错：

Error communicating with OpenAI API. Status code: BadRequest
Error content: {
"error": {
"message": "'messages' is a required property",
"type": "invalid_request_error",
"param": null,
"code": null
}
}

曾尝试在requestBody中添加messages = query，但提示该值为空，陷入困境。问题代码如下：

public async Task<string> GetOpenAiResponse(string query)
{
    using (HttpClient client = new HttpClient())
    {
        client.DefaultRequestHeaders.Add("Authorization", $"Bearer {GptApiKey}");

        string prompt = $"User: {query}\nChatGPT:";

        // Create a JSON object for the request payload
        var requestBody = new
        {
            prompt = prompt,
            model = "gpt-3.5-turbo",
            max_tokens = 150
        };

        // Serialize the JSON object to a string
        var jsonContent = JsonConvert.SerializeObject(requestBody);

        // Use StringContent with the correct content type
        var content = new StringContent(jsonContent, Encoding.UTF8, "application/json");

        var response = await client.PostAsync("https://api.openai.com/v1/chat/completions", content);


        if (response.IsSuccessStatusCode)
        {
            string result = await response.Content.ReadAsStringAsync();

            // Parsing JSON to extract the response text
            var jsonResponse = JObject.Parse(result);
            var choices = jsonResponse["choices"];
            var firstChoice = choices.FirstOrDefault();
            var text = firstChoice?["text"].ToString();

            return text ?? "Unable to parse OpenAI response.";
        }
        else
        {
            Console.WriteLine($"Error communicating with OpenAI API. Status code: {response.StatusCode}");
            string errorContent = await response.Content.ReadAsStringAsync();
            Console.WriteLine($"Error content: {errorContent}");

            return "Error communicating with OpenAI API.";
        }
    }
}

参考Jon的答案后修改代码，机器人已可正常运行，正确代码如下：

public async Task<string> GetOpenAiResponse(string query)
{
    using (HttpClient client = new HttpClient())
    {
        client.DefaultRequestHeaders.Add("Authorization", $"Bearer {GptApiKey}");

        string prompt = $"User: {query}\nChatGPT:";
        // Create message objects for the system and user messages
        var messages = new List<object>
    {
        new { role = "system", content = "You are a helpful assistant." },
        new { role = "user", content = query }
    };
        // Create a JSON object for the request payload
        var requestBody = new
        {
          
            model = "gpt-3.5-turbo",
            messages = messages,
            max_tokens = 150
        };

        // Serialize the JSON object to a string
        var jsonContent = JsonConvert.SerializeObject(requestBody);

        // Use StringContent with the correct content type
        var content = new StringContent(jsonContent, Encoding.UTF8, "application/json");

        var response = await client.PostAsync("https://api.openai.com/v1/chat/completions", content);


        if (response.IsSuccessStatusCode)
        {
            string result = await response.Content.ReadAsStringAsync();

            // Parsing JSON to extract the response text
            var jsonResponse = JObject.Parse(result);
            var choices = jsonResponse["choices"];
            var firstChoice = choices.FirstOrDefault();
            var text = firstChoice["message"]["content"].ToString();

            return text ?? "Unable to parse OpenAI response.";
        }
        else
        {
            Console.WriteLine($"Error communicating with OpenAI API. Status code: {response.StatusCode}");
            string errorContent = await response.Content.ReadAsStringAsync();
            Console.WriteLine($"Error content: {errorContent}");

            return "Error communicating with OpenAI API.";
        }
    }
}

内容的提问来源于stack exchange，提问作者Voidpool