Text to image

Text to image generates an image from a text prompt. A complete, specific prompt produces an image closer to what you want.

Models

Model	Max resolution	Notes
doubao-seedream-5-0-260128	4096x4096	Sequential images, multi-image fusion, and web search
doubao-seedream-5-0-pro-260628	2048x2048	Higher fidelity, interactive editing, and layer splitting

Request parameters

Parameter	Description	Required	Type
model	Model ID	Yes	String
prompt	Text description. Describe the subject, details, and scene.	Yes	String
size	Resolution tier, or pixel size as widthxheight	No	String
response_format	url or b64_json	No	String
watermark	Whether to add a watermark	No	Boolean

Writing a prompt

A useful prompt usually includes:

1. Subject: the main object in the frame
2. Details: color, material, texture
3. Setting: time, place, mood
4. Style: art style, photographic style
5. Composition: angle, focal length, depth of field

Example:

A cute kitten playing in a garden, bright sunlight, vivid colors, watercolor style

size values

Use one method. Do not mix them.

Option 1: resolution tier (recommended). Describe aspect ratio, shape, or use in the prompt and let the model pick the exact size.

Model	Tiers	Default
doubao-seedream-5-0-260128	2K, 3K, 4K	2K
doubao-seedream-5-0-pro-260628	1K, 1.5K, 2K	2K

Option 2: pixel size (widthxheight). The total pixel count and the aspect ratio must both fall in [1/16, 16].

Model	Total pixel range	Default
doubao-seedream-5-0-260128	[2560x1440, 4096x4096]	2048x2048
doubao-seedream-5-0-pro-260628	[1280x720, 2048x2048×1.1025]	2K

Reference sizes for doubao-seedream-5-0-260128:

Tier	1:1	16:9	9:16	4:3	3:4
2K	2048x2048	2848x1600	1600x2848	2304x1728	1728x2304
4K	4096x4096	5504x3040	3040x5504	4704x3520	3520x4704

Pixel sizes for each tier of doubao-seedream-5-0-pro-260628 differ slightly. Follow the official Doubao documentation.

Examples

doubao-seedream-5-0-260128

curl -X POST https://api-ai.xiaoku.ai/doubao/api/v3/images/generations \
  -H "Authorization: Bearer XIAOKU_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "doubao-seedream-5-0-260128",
    "prompt": "A bamboo grove in the rain, a winding path, mist, fresh and natural",
    "size": "2K",
    "watermark": false
  }'

doubao-seedream-5-0-pro-260628 (high fidelity)

curl -X POST https://api-ai.xiaoku.ai/doubao/api/v3/images/generations \
  -H "Authorization: Bearer XIAOKU_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "doubao-seedream-5-0-pro-260628",
    "prompt": "A fine landscape oil painting, a mountain stream, snow peaks in the distance, mist, sunlight breaking through clouds onto the water",
    "size": "2K",
    "watermark": false
  }'

Response

{
    "model": "doubao-seedream-5-0-260128",
    "created": 1757321139,
    "data": [
        {
            "url": "https://api-ai.xiaoku.ai/images/xxx.jpg",
            "size": "2048x2048"
        }
    ],
    "usage": {
        "generated_images": 1
    }
}

Notes

1. Keep prompts under 300 Chinese characters or 600 English words
2. Image URLs expire after 24 hours. Save them promptly.