completions

Create text completion

Create a text completion, supports streaming

Request

POST /completions

Request Body

Field	Type	Required	Description
model	string	Yes	Model name
prompt	string	Yes	Prompt text
best_of	integer	No	Generate multiple results and return the best one
echo	boolean	No	Whether to echo the prompt
frequency_penalty	number	No	-
logit_bias	object	No	-
max_tokens	integer	No	-
n	integer	No	-
presence_penalty	number	No	-
seed	integer	No	-
stop	string	No	-
stream	boolean	No	-
temperature	number	No	-
top_p	number	No	-
user	string	No	-

Request Examples

Simple text completion

{
  "model": "gpt-4o-mini",
  "prompt": "Once upon a time",
  "max_tokens": 50
}

Completion with options

{
  "model": "qwen-plus",
  "prompt": "Write a haiku about coding",
  "max_tokens": 100,
  "temperature": 0.8,
  "top_p": 1,
  "n": 1
}

Streaming completion

{
  "model": "gpt-4o-mini",
  "prompt": "List 3 benefits of unit testing",
  "max_tokens": 64,
  "stream": true,
  "stop": [
    "\n\n"
  ]
}

Code completion example

{
  "model": "qwen3-coder-plus",
  "prompt": "def fibonacci(n):",
  "max_tokens": 80,
  "temperature": 0.3,
  "top_p": 0.9
}

Successful response

Response Schema

Field	Type	Required	Description
id	string	Yes	-
object	string	Yes	-
created	integer	Yes	-
model	string	Yes	-
choices	Array<CompletionChoice>	Yes	-
usage	object	No	-

Response Example

{
  "id": "cmpl-123",
  "object": "completion",
  "created": 1677652288,
  "model": "gpt-4o-mini",
  "choices": [
    {
      "text": ", there was a young programmer who loved to code.",
      "index": 0,
      "logprobs": null,
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 5,
    "completion_tokens": 12,
    "total_tokens": 17
  }
}

Code Examples

JavaScript (Fetch)

const response = await fetch('https://api.r9s.ai/v1/completions', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
  "model": "gpt-4o-mini",
  "prompt": "Once upon a time",
  "max_tokens": 50
})
});

const data = await response.json();
console.log(data);

Python (requests)

import requests

url = "https://api.r9s.ai/v1/completions"
headers = {
    "Authorization": "Bearer YOUR_API_KEY",
    "Content-Type": "application/json"
}

response = requests.post(url, json={
  "model": "gpt-4o-mini",
  "prompt": "Once upon a time",
  "max_tokens": 50
}, headers=headers)
data = response.json()
print(data)

cURL

curl -X POST "https://api.r9s.ai/v1/completions" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"gpt-4o-mini","prompt":"Once upon a time","max_tokens":50}'

Schema Reference

CompletionRequest

Field	Type	Required	Description
model	string	Yes	Model name
prompt	string	Yes	Prompt text
best_of	integer	No	Generate multiple results and return the best one
echo	boolean	No	Whether to echo the prompt
frequency_penalty	number	No	-
logit_bias	object	No	-
max_tokens	integer	No	-
n	integer	No	-
presence_penalty	number	No	-
seed	integer	No	-
stop	string	No	-
stream	boolean	No	-
temperature	number	No	-
top_p	number	No	-
user	string	No	-

CompletionResponse

Field	Type	Required	Description
id	string	Yes	-
object	string	Yes	-
created	integer	Yes	-
model	string	Yes	-
choices	Array<CompletionChoice>	Yes	-
usage	object	No	-

CompletionChoice

Field	Type	Required	Description
text	string	Yes	-
index	integer	Yes	-
logprobs	object	No	-
finish_reason	string (stop, length, content_filter)	Yes	-

Usage

Field	Type	Required	Description
prompt_tokens	integer	Yes	Number of tokens in the prompt (input)
prompt_tokens_details	object	No	Details about prompt tokens
completion_tokens	integer	Yes	Number of tokens in the completion (output)
completion_tokens_details	object	No	Details about completion tokens
total_tokens	integer	Yes	Total number of tokens (prompt + completion)

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