POST
/
v1
/
completions
curl -X POST https://api.example.com/v1/completions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-3.5-turbo-instruct",
    "prompt": "Hello,",
    "max_tokens": 30,
    "temperature": 0
  }'

{
  "id": "cmpl-ByvHP6AWeB1L5vWZSPNHsB12sU9db",
  "object": "text_completion",
  "created": 1753859563,
  "model": "gpt-3.5-turbo-instruct",
  "choices": [
    {
      "index": 0,
      "logprobs": null,
      "finish_reason": "length",
      "text": "I am an AI assistant. How can I help you today?"
    }
  ],
  "usage": {
    "prompt_tokens": 3,
    "completion_tokens": 30,
    "total_tokens": 33
  }
}
Official documentation: https://platform.openai.com/docs/api-reference/completions
Given a prompt, the model will return one or more predicted completions, and can also return the probabilities of alternative tokens at each position.

​
Request Parameters

​
model
string
required
ID of the model to use. You can use the List models API to see all available models.
​
prompt
string
required
The prompt to generate completions for, encoded as a string, array of strings, array of tokens, or array of token arrays.
​
max_tokens
integer
default:"16"
The maximum number of tokens to generate in the completion.
​
temperature
number
default:"1"
Sampling temperature between 0 and 2. Higher values make output more random, lower values make it more focused.
​
top_p
number
default:"1"
Nucleus sampling parameter.
​
n
integer
default:"1"
Number of completions to generate for each prompt.
​
stream
boolean
default:"false"
Whether to stream back partial progress.
​
logprobs
integer
Include the log probabilities of the most likely tokens. Maximum value is 5.
​
echo
boolean
default:"false"
Echo back the prompt in addition to the completion.
​
stop
string | array
Up to 4 sequences where the API will stop generating further tokens.
​
presence_penalty
number
default:"0"
Number between -2.0 and 2.0. Positive values penalize new tokens based on whether they appear in the text so far.
​
frequency_penalty
number
default:"0"
Number between -2.0 and 2.0. Positive values penalize new tokens based on their existing frequency in the text.
​
best_of
integer
default:"1"
Generates best_of completions server-side and returns the “best” one.

​
Response

​
id
string
Unique identifier for the completion.
​
object
string
Object type, which is text_completion.
​
created
integer
Unix timestamp of when the completion was created.
​
model
string
The model used for completion.
​
choices
array
List of completion choices.
​
usage
object
Usage statistics for the completion request.
curl -X POST https://api.example.com/v1/completions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-3.5-turbo-instruct",
    "prompt": "Hello,",
    "max_tokens": 30,
    "temperature": 0
  }'

{
  "id": "cmpl-ByvHP6AWeB1L5vWZSPNHsB12sU9db",
  "object": "text_completion",
  "created": 1753859563,
  "model": "gpt-3.5-turbo-instruct",
  "choices": [
    {
      "index": 0,
      "logprobs": null,
      "finish_reason": "length",
      "text": "I am an AI assistant. How can I help you today?"
    }
  ],
  "usage": {
    "prompt_tokens": 3,
    "completion_tokens": 30,
    "total_tokens": 33
  }
}