Seedream 5.5 - PoYo AI

curl --request POST \
  --url https://api.poyo.ai/api/generate/submit \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "seedream-5.5",
  "input": {
    "prompt": "A ceramic pour-over coffee set on a walnut counter, soft morning window light, steam rising from the cup, minimalist product photography",
    "size": "16:9",
    "resolution": "2K"
  }
}
'

{
  "code": 200,
  "data": {
    "task_id": "task-unified-1794470400-abcd1234",
    "status": "not_started",
    "created_time": "2026-11-12T10:30:00"
  }
}

{
  "code": 400,
  "error": {
    "message": "Invalid request parameters",
    "type": "invalid_request_error"
  }
}

{
  "code": 400,
  "error": {
    "message": "Invalid request parameters",
    "type": "invalid_request_error"
  }
}

POST

api

generate

submit

curl --request POST \
  --url https://api.poyo.ai/api/generate/submit \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "seedream-5.5",
  "input": {
    "prompt": "A ceramic pour-over coffee set on a walnut counter, soft morning window light, steam rising from the cup, minimalist product photography",
    "size": "16:9",
    "resolution": "2K"
  }
}
'

{
  "code": 200,
  "data": {
    "task_id": "task-unified-1794470400-abcd1234",
    "status": "not_started",
    "created_time": "2026-11-12T10:30:00"
  }
}

{
  "code": 400,
  "error": {
    "message": "Invalid request parameters",
    "type": "invalid_request_error"
  }
}

{
  "code": 400,
  "error": {
    "message": "Invalid request parameters",
    "type": "invalid_request_error"
  }
}

After submission, a task_id will be returned. If you provided a callback_url, when the task status becomes finished or failed, a POST request will be sent to the callback_url.
Regardless of whether callback_url is provided, you can retrieve the response result through the unified Query Task Status endpoint.

Use seedream-5.5 to create product shots, posters, stickers, and other images from a prompt, or to edit and combine up to 10 reference images with the same model ID. Seedream 5.5 is ByteDance Seed’s image creation model, released on November 9, 2026. It keeps unedited regions stable across repeated edits and outputs native transparent PNGs. To split an image into a base image and transparent layers, use Seedream 5.5 Layer Decomposition.

Models

seedream-5.5 — Text-to-image when image_urls is omitted; image editing with 1 to 10 reference images when image_urls is provided

Features

Text-to-image generation from prompts of 5 to 5,000 characters.
Image editing and multi-reference composition with up to 10 reference images.
Consistent multi-round editing: pass the previous result as the next reference image and the regions you leave out of the prompt stay the same.
Native transparent output: set background to transparent for an RGBA PNG with full or partial transparency, from a prompt or from reference images.
Eight aspect ratios at 1K, 1.5K, or 2K (up to 3136×1344 at 21:9).
PNG or JPEG output.

Input modes

Text-to-image — Omit image_urls. size defaults to 1:1.
Image editing — Pass 1 to 10 URLs in image_urls. Refer to the images in the prompt by their order (image 1, image 2, and so on). size defaults to auto, which follows the reference images.

Required parameters

prompt (string): Description of the image or the requested edit, 5–5,000 characters. For an edit, say what changes and what stays the same.

Optional parameters

image_urls (array of strings): 1 to 10 publicly accessible HTTP(S) reference image URLs (JPEG, PNG, or WEBP, up to 10 MB each). Selects image editing mode.
size (string): 1:1, 4:3, 3:4, 16:9, 9:16, 3:2, 2:3, 21:9, or auto. Defaults to 1:1 for text-to-image and auto for image editing. auto applies to image editing. See Size.
resolution (string): 1K, 1.5K, or 2K. Default is 2K. Sets the pixel tier for the selected size.
background (string): auto, transparent, or opaque. Default is auto, where the prompt and output format decide the background. transparent returns an RGBA image with an alpha channel and needs output_format png. opaque returns an RGB image.
output_format (string): png or jpeg. Default is png.
enable_safety_checker (boolean): Content safety check. Default is true.

Size

Each aspect ratio maps to fixed pixel dimensions at the selected resolution:

`size`	`1K`	`1.5K`	`2K`
`1:1`	1024×1024	1536×1536	2048×2048
`4:3`	1152×864	1792×1344	2368×1776
`3:4`	864×1152	1344×1792	1776×2368
`16:9`	1424×800	2048×1152	2816×1584
`9:16`	800×1424	1152×2048	1584×2816
`3:2`	1248×832	1872×1248	2496×1664
`2:3`	832×1248	1248×1872	1664×2496
`21:9`	1568×672	2352×1008	3136×1344

auto (image editing): The output follows the reference images at about the pixel area of the selected resolution.

Examples

Text To Image

A 2K 16:9 product shot (2816×1584):

{
  "model": "seedream-5.5",
  "input": {
    "prompt": "A ceramic pour-over coffee set on a walnut counter, soft morning window light, steam rising from the cup, minimalist product photography",
    "size": "16:9",
    "resolution": "2K"
  }
}

Multi-Reference Edit

Combine two reference images, referring to each one by its position in image_urls:

{
  "model": "seedream-5.5",
  "input": {
    "prompt": "Put the handbag from image 2 on the wooden table in image 1. Keep the lighting, background, and camera angle of image 1 unchanged.",
    "image_urls": [
      "https://example.com/living-room.png",
      "https://example.com/handbag.png"
    ],
    "resolution": "2K"
  }
}

Transparent PNG

A sticker on a transparent background:

{
  "model": "seedream-5.5",
  "input": {
    "prompt": "A red paper lantern with golden tassels, flat illustration sticker, isolated subject on a transparent background",
    "size": "1:1",
    "resolution": "1K",
    "background": "transparent",
    "output_format": "png"
  }
}

Notes

Each request generates one image.
Pass image_urls as an array, including for a single image.
For multi-round editing, use the previous result as the next reference image and keep background at opaque or auto until the final transparent step.
A request usually finishes in about 20 to 35 seconds.

Authorizations

Authorization

string

header

required

All API endpoints require Bearer Token authentication.

Create an API key: sign in to PoYo, open Dashboard → API Key at poyo.ai/dashboard/api-key, and click to create a key.

Add it to the request header:

Authorization: Bearer YOUR_API_KEY

Body

application/json

model

enum<string>

required

Seedream 5.5 model identifier. Omit image_urls for text-to-image; pass 1–10 image_urls for image editing.

Available options:

seedream-5.5

input

object

required

Generate one image. With image_urls, edit or combine the reference images.

Show child attributes

callback_url

string<uri>

Optional webhook URL for task completion or failure.

Response

Task submitted successfully

code

enum<integer>

required

Business status code. 200 means success; any other value means the request failed. Always check this field: some validation errors return HTTP 200 with code: 400 in the body.

200: Success
400: Invalid request parameters
401: Missing or invalid API key
402: Insufficient credits
403: Permission denied
404: Resource not found
408: Request timeout
429: Rate limit exceeded
500: Internal server error
502: Upstream service error
503: Service unavailable

See Error Codes for details.

Available options:

200,

400,

401,

402,

403,

404,

408,

429,

500,

502,

503

Example:

200

data

object

required

Show child attributes

​Models

​Features

​Input modes

​Required parameters

​Optional parameters

​Size

​Examples

​Text To Image

​Multi-Reference Edit

​Transparent PNG

​Notes

Authorizations

Body

Response

Models

Features

Input modes

Required parameters

Optional parameters

Size

Examples

Text To Image

Multi-Reference Edit

Transparent PNG

Notes