This API utilizes the OpenAI API to answer user queries.

The OpenAI expected Input

{
  "model": "text-davinci-003",
  "prompt": "Say this is a test",
  "max_tokens": 7,
  "temperature": 0,
  "top_p": 1,
  "n": 1,
  "stream": false,
  "logprobs": null,
  "stop": "\n"
}

You can see that the post body defines some parameters some of which are optional except for the model parameter.

For this project I only used 4 parameters:

model expects a String, we will keep the same model as the example which is text-davinci-003 but you can check their overview for more models.

prompt expects a String or an Array, it will contain the question we want to ask ChatGPT.

temperature expects a Number.

max_tokens expects an Integer.

You can play around with temperature and max_tokens values but will use 4096 and 1 respectively.

The expected Output

{
  "id": "cmpl-uqkvlQyYK7bGYrRHQ0eXlWi7",
  "object": "text_completion",
  "created": 1589478378,
  "model": "text-davinci-003",
  "choices": [
    {
      "text": "\n\nThis is indeed a test",
      "index": 0,
      "logprobs": null,
      "finish_reason": "length"
    }
  ],
  "usage": {
    "prompt_tokens": 5,
    "completion_tokens": 7,
    "total_tokens": 12
  }
}

The most interesting property here is "text" which is a String, it will contain the answer to the question sent earlier to the API.

You can hardcode the parameters inside the constructor or use the application.properties with the necessary variables.

To generate your OpenAI API Key visite this page

https://platform.openai.com/account/api-keys

Click on Create new secret key

In the Service Java class I added the methods that will communicate with the API

To understand the next steps take a look at an Example of a request

curl https://api.openai.com/v1/completions \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -d '{
  "model": "text-davinci-003",
  "prompt": "Say this is a test",
  "max_tokens": 7,
  "temperature": 0
}'

This request expects a URL that points to the API, A header that defines the content type as JSON object, An authorization header as a Bearer Token And the body

So I built an http client request that will take the parameters defined above and send it to the URI. The answer will then be returned as a Json String.