`index` in OpenGPT API output

Question

The following is the code

import os
import openai


openai.api_key = "..."


response = openai.Completion.create(
  model="text-davinci-003",     
  prompt="I am happy!",
  temperature=0, #creativity
  max_tokens=10,
  top_p=1,
  frequency_penalty=0.0,
  presence_penalty=0.0,
  suffix='I am even more happy!'
)

print(response)

Following is the output

{
  "choices": [
    {
      "finish_reason": "length",
      "index": 0,
      "logprobs": null,
      "text": "\n\nI am happy because I am surrounded by"
    }
  ],
  "created": 1674640360,
  "id": "cmpl-6cWkK124234ho8C2134afasdasdnwDKLUMP",
  "model": "text-davinci-003",
  "object": "text_completion",
  "usage": {
    "completion_tokens": 10,
    "prompt_tokens": 10,
    "total_tokens": 20
  }
}

What does the index in above following output represent?

Answer 1

The index refers to the index of the prompt the reply is for.

Since prompt can be an string or an array, the documentation refers to it as:

prompt ^{string or array}

The prompt(s) to generate completions for, encoded as a string , array of strings , array of tokens, or array of token arrays.

---

As example, consider calling the /completions endpoint with 2 prompt 's:

{
    "model": "text-davinci-003",
    "prompt": [ 
      "How should I",                            // [ 0 ]
      "Should I"                                 // [ 1 ] 
    ],
    "max_tokens": 7,
    "temperature": 0
}

OpenAI will answer to both those prompts, and the index will refer to what original index in the prompt the reply is for:

{
    "choices": [
        {
            "text": " go about doing this?\n\n",
            "index": 0,                              // Answers prompt[0]
            "logprobs": null,
            "finish_reason": "length"
        },
        {
            "text": " use a VPN on my iPhone?",
            "index": 1,                              // Answers prompt[1]
            "logprobs": null,
            "finish_reason": "length"
        }
    ]
}

---

In your example, there is only 1 prompt , so the API will only send 1 object in the choices array, so the index will always be 0 .