OpenAI Generations

/v1/images/generations is the OpenAI Images API compatible synchronous image generation endpoint. The HTTP request completes after the image result is ready.

Interface

Item	Value
Method	POST
Path	/v1/images/generations
Content-Type	application/json
Authentication	Authorization: Bearer YOUR_API_KEY
Platform requirement	Requires an OpenAI platform group with image generation enabled.

Request Parameters

Parameter	Type	Required	Description
model	string	No	OpenAI Images compatible model. Defaults to gpt-image-2.
prompt	string	Yes	Image generation prompt.
size	string	No	Output size, such as 1024x1024.
n	integer	No	Number of images. Defaults to 1 and must be greater than 0.
response_format	string	No	Response format, commonly b64_json.
stream	boolean	No	Whether to stream the response when supported by the selected model.
quality	string	No	OpenAI Images API parameter. Availability depends on the selected model.
background	string	No	OpenAI Images API parameter. Availability depends on the selected model.
output_format	string	No	OpenAI Images API parameter. Availability depends on the selected model.
output_compression	integer	No	OpenAI Images API parameter. Availability depends on the selected model.
moderation	string	No	OpenAI Images API parameter. Availability depends on the selected model.
style	string	No	OpenAI Images API parameter. Availability depends on the selected model.

Request Example

curl https://api.llmapi.site/v1/images/generations \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "gpt-image-2",
    "prompt": "a product photo of a ceramic coffee cup on a white table",
    "size": "1024x1024",
    "n": 1,
    "response_format": "b64_json"
  }'

Response — 200 OK

{
  "created": 1779912000,
  "data": [
    {
      "b64_json": "..."
    }
  ]
}

Field	Description
created	Unix timestamp when the response was created.
data[].b64_json	Base64 image payload when response_format is b64_json.
data[].url	Image URL when URL responses are available.

Errors

Status	Cause
400	Request body is invalid, the model is not an image model, or required parameters are missing.
401	API key is missing or invalid.
403	Balance, quota, or group permission check failed.
404	Current API key group cannot call the OpenAI Images API.
429	Rate limit or concurrency limit was reached.
500 / 502 / 503	Gateway or upstream provider failed.

Boundaries

• This endpoint is only for OpenAI Images API compatible requests.