Krea 3 API Reference

AUTHENTICATION

Bearer Token Authentication

All requests to the LumozAI API require authentication using your secret API key. Pass your key in the standard Authorization HTTP header as a Bearer token.

cURL Authorization Header Quickstart

curl -X POST https://lumozai.com/api/v4/run \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Accept: application/json" \
  -d "model_id=krea-3" \
  -d "prompt=A futuristic cityscape illuminated by neon bioluminescence"

PHP cURL Request

<?php
$apiKey = 'YOUR_API_KEY';

$curl = curl_init();
curl_setopt_array($curl, [
    CURLOPT_URL => 'https://lumozai.com/api/v4/run',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => [
        'model_id' => 'krea-3',
        'prompt' => 'A futuristic cityscape illuminated by neon bioluminescence'
    ],
    CURLOPT_HTTPHEADER => [
        'Accept: application/json',
        'Authorization: Bearer ' . $apiKey
    ]
]);

$response = curl_exec($curl);
curl_close($curl);

$result = json_decode($response, true);
print_r($result);

POST /api/v4/run

Execute Krea 3 Inference

Submit a synchronous or asynchronous generation job for Krea 3 (krea-3). Fast-running image models return the generated asset directly; longer inference pipelines return a request_id for asynchronous polling.

Request Parameters for Krea 3

10 total fields

Parameter	Type	Required	Default	Description / Allowed Values
`model_id`	string	Required	`krea-3`	Unique model identifier. Must be set to `krea-3`.
`prompt` Prompt / Instruction	string	Required	—	Instruction describing the image to generate, or the edit to make. For edits, specify what should change and what should stay the same.
`images` Reference Images (Optional)	array of URLs	Optional	—	Up to 8 input reference images to edit, restyle, or combine. Leave empty for text-to-image generation.
`aspect_ratio` Aspect Ratio	enum	Optional	`auto`	Aspect ratio of the generated image. "auto" picks the optimal framing from your prompt or input images. auto 1:1 16:9 9:16 4:3 3:4 3:2 2:3 4:5 5:4 21:9
`resolution` Resolution	enum	Optional	`2k`	Output image resolution tier. 2k 1k
`thinking_mode` Thinking Mode	enum	Optional	`fast`	How much reasoning and planning happens before generation. "fast" is rapid and works for most requests. "high" plans complex multi-step edits more thoroughly. fast high
`regional_edit` Regional Edit Mode	enum	Optional	`false`	Change only specific parts of the image and keep the rest untouched (requires at least one reference image). false true
`negative_prompt` Negative Prompt (Optional)	string	Optional	—	Specific visual artifacts, concepts, or elements to avoid in the output.
`seed` Random Seed (Optional)	number	Optional	—	Specific random seed integer.
`webhook`	string (URL)	Optional	—	Optional callback URL to receive an HTTP POST when async generation completes.

Model-Specific Integration Code

Copy-paste production snippets configured with krea-3 and tailored parameter inputs.

cURL POST /api/v4/run (krea-3)

curl -X POST https://lumozai.com/api/v4/run \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Accept: application/json" \
  -d "model_id=krea-3" \
  -d "prompt=A futuristic cybernetic metropolis illuminated by neon bioluminescence, 8k cinematic masterpiece" \
  -d "images[]=https://lumozai.com/samples/sample_input.jpg" \
  -d "aspect_ratio=auto" \
  -d "resolution=2k" \
  -d "thinking_mode=fast" \
  -d "regional_edit=false" \
  -d "negative_prompt=sample_value" \
  -d "seed=25"

Python requests.post (krea-3)

import requests

url = "https://lumozai.com/api/v4/run"
headers = {
    "Authorization": "Bearer YOUR_API_KEY",
    "Accept": "application/json"
}
payload = {
    "model_id": "krea-3",
    "prompt": "A futuristic cybernetic metropolis illuminated by neon bioluminescence, 8k cinematic masterpiece",
    "images": ["https:\/\/lumozai.com\/samples\/sample_input.jpg"],
    "aspect_ratio": "auto",
    "resolution": "2k",
    "thinking_mode": "fast",
    "regional_edit": "false",
    "negative_prompt": "sample_value",
    "seed": 25
}

response = requests.post(url, headers=headers, json=payload)
print(response.json())

PHP cURL POST (krea-3)

<?php
$apiKey = 'YOUR_API_KEY';

$curl = curl_init();
curl_setopt_array($curl, [
    CURLOPT_URL => 'https://lumozai.com/api/v4/run',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => [
        'model_id' => 'krea-3',
        'prompt' => 'A futuristic cybernetic metropolis illuminated by neon bioluminescence, 8k cinematic masterpiece',
        'images[]' => 'https://lumozai.com/samples/sample_input.jpg',
        'aspect_ratio' => 'auto',
        'resolution' => '2k',
        'thinking_mode' => 'fast',
        'regional_edit' => 'false',
        'negative_prompt' => 'sample_value',
        'seed' => 25
    ],
    CURLOPT_HTTPHEADER => [
        'Accept: application/json',
        'Authorization: Bearer ' . $apiKey
    ]
]);

$response = curl_exec($curl);
curl_close($curl);

$result = json_decode($response, true);
print_r($result);

JavaScript fetch async/await (krea-3)

const response = await fetch('https://lumozai.com/api/v4/run', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json',
    'Accept': 'application/json'
  },
  body: JSON.stringify({
    "model_id": "krea-3",
    "prompt": "A futuristic cybernetic metropolis illuminated by neon bioluminescence, 8k cinematic masterpiece",
    "images": ["https:\/\/lumozai.com\/samples\/sample_input.jpg"],
    "aspect_ratio": "auto",
    "resolution": "2k",
    "thinking_mode": "fast",
    "regional_edit": "false",
    "negative_prompt": "sample_value",
    "seed": 25
  })
});

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

Response Structure (200 OK)

JSON Output

{
  "success": true,
  "data": {
    "request_id": 982348712938172,
    "output": "https://lumozai.com/storage/outputs/result_krea-3_9823.png",
    "output_type": "image"
  }
}

POST /api/v4/check

Poll Asynchronous Task Status

Poll the current execution state of an asynchronous job using the returned request_id.

Request Parameters

Parameter	Type	Required	Description
`request_id`	integer	Required	The unique job ID returned when calling `/api/v4/run`.

JSON Completed Status (200 OK)

{
  "success": true,
  "data": {
    "request_id": 982348712938172,
    "status": "completed",
    "output": "https://lumozai.com/storage/outputs/video_8172.mp4",
    "output_type": "video"
  }
}

JSON In-Progress Status (200 OK)

{
  "success": true,
  "data": {
    "request_id": 982348712938172,
    "status": "processing",
    "progress": 68
  }
}

ERROR HANDLING

Standard Error Codes

The API uses conventional HTTP response codes to indicate success or failure. In general, 2xx indicates success, 4xx indicates client input issues, and 5xx indicates server errors.

Status	Error Code	Description
401	`authentication_failed`	Missing or invalid Authorization Bearer header.
403	`permission_denied`	Insufficient credits or account tier permissions.
404	`model_not_found`	The specified `model_id` does not exist or is deprecated.
422	`validation_error`	Missing required parameters or invalid parameter types.
429	`rate_limit_exceeded`	Request rate quota exceeded for your tier.
500	`internal_server_error`	Downstream GPU compute error or worker timeout.

JSON Validation Error Example

{
  "success": false,
  "error": {
    "code": "validation_error",
    "message": "The model_id field is required.",
    "details": {
      "model_id": ["The model_id field is required."]
    }
  }
}

RATE LIMITS

Quota & Throughput Limits

Rate limits are enforced per API key to guarantee fair access and consistent low latency across GPU workers. Every API response includes informative headers:

Header	Description
`X-RateLimit-Limit`	Maximum number of requests permitted per rolling hour.
`X-RateLimit-Remaining`	Number of remaining requests in the active window.
`X-RateLimit-Reset`	Unix epoch timestamp when the current window refreshes.

Handling 429 Status Codes: When rate-limited, wait for the number of seconds until X-RateLimit-Reset or implement an exponential backoff retry mechanism. Need custom enterprise rate limits? Contact our team.