OpenAI Chat Completions API error: "Request failed with status code 400"

I want to upgrade my GPT-3 to GPT-3.5 Turbo in Node.js. But I have a problem with that.

My code:

const askAi = async (message) => {
  try {
    const openAIInstance = await _createOpenAIInstance()

    const response = await openAIInstance.createCompletion({
      model: 'gpt-3.5-turbo',
      messages: [{ role: 'user', content: message }]
    })

    const repliedMessage = response.data.choices[0].message.content

    return repliedMessage
  } catch (err) {
    logger.error('', '', 'Ask AI Error: ' + err.message)
    return sendInternalError(err)
  }
}

But when I try to input the message:

askAi('Suggest me a job position for Auto CAD user')

It's returning an error:

Request failed with status code 400 

Problem

You used the wrong function to get a completion for the given model.

The function createCompletion works with the Completions API. In other words, the function createCompletion works with GPT-3 models (e.g., text-davinci-003) or GPT base models (e.g., davinci-002).

Solution

Note: OpenAI NodeJS SDK v4 was released on August 16, 2023, and is a complete rewrite of the SDK. Among other things, there are changes in method names. See the v3 to v4 migration guide.

• If you have the OpenAI NodeJS SDK v3: Change createCompletion to createChatCompletion

const askAi = async (message) => {
  try {
    const openAIInstance = await _createOpenAIInstance()

    const response = await openAIInstance.createChatCompletion({
      model: 'gpt-3.5-turbo',
      messages: [{ role: 'user', content: message }]
    })

    const repliedMessage = response.data.choices[0].message.content

    return repliedMessage
  } catch (err) {
    logger.error('', '', 'Ask AI Error: ' + err.message)
    return sendInternalError(err)
  }
}

• If you have the OpenAI NodeJS SDK v4: Change createCompletion to chat.completions.create

Note: There are also changes in extracting the message content in v4.

const askAi = async (message) => {
  try {
    const openAIInstance = await _createOpenAIInstance()

    const response = await openAIInstance.chat.completions.create({
      model: 'gpt-3.5-turbo',
      messages: [{ role: 'user', content: message }]
    })

    const repliedMessage = response.choices[0].message.content

    return repliedMessage
  } catch (err) {
    logger.error('', '', 'Ask AI Error: ' + err.message)
    return sendInternalError(err)
  }
}