Seedream 5.0 Pro API

ByteDance Seedream 5.0 Pro image generation API for single-image text-to-image and image-to-image workflows

Overview

Seedream 5.0 Pro is a ByteDance image generation model for high-quality single-image text-to-image creation and reference-guided image generation. It supports 1K and 2K resolution tiers, flexible aspect ratios, optional explicit pixel sizes, and jpeg or png output.

Capability	Value
Model ID	seedream-5-0-pro
Modes	text-to-image, image-to-image
Prompt length	1-5000 characters
Reference images	Required for image-to-image; 1-10 public image URLs
Images per task	Exactly 1 output image
Resolution tiers	1K, 2K
Aspect ratios	1:1, 2:3, 3:2, 4:3, 3:4, 9:16, 16:9, 21:9
Size input	1K, 2K, 1024x1024, 2048X2048, 2048*2048
Output formats	jpeg, png

Endpoint and authentication

Base URL:

https://api.apixo.ai/api/v1

Method	Endpoint	Purpose
POST	/generateTask/seedream-5-0-pro	Submit a generation task
GET	/statusTask/seedream-5-0-pro?taskId={taskId}	Poll task status and retrieve results

All requests require your APIXO API key:

Authorization: Bearer YOUR_API_KEY

Submit requests also require:

Content-Type: application/json

Copy-paste async quickstart

This minimal request submits a text-to-image task and returns a taskId.

curl -X POST "https://api.apixo.ai/api/v1/generateTask/seedream-5-0-pro" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "input": {
      "mode": "text-to-image",
      "prompt": "a cinematic product photo of wireless earbuds on black glass, crisp highlights",
      "resolution": "1K",
      "aspect_ratio": "1:1",
      "output_format": "jpeg"
    }
  }'

Successful response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678"
  }
}

Save the taskId; you need it to poll for the final result.

Poll for result

curl -X GET "https://api.apixo.ai/api/v1/statusTask/seedream-5-0-pro?taskId=task_12345678" \
  -H "Authorization: Bearer YOUR_API_KEY"

Success response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "success",
    "resultJson": "{\"resultUrls\":[\"https://file.apixo.ai/xxx.jpeg\"]}",
    "createTime": 1767965610929,
    "completeTime": 1767965644132,
    "costTime": 33203
  }
}

Request body

Text-to-image

{
  "input": {
    "mode": "text-to-image",
    "prompt": "a clean product photo of wireless earbuds on soft stone",
    "resolution": "1K",
    "aspect_ratio": "1:1",
    "output_format": "jpeg"
  }
}

Image-to-image

{
  "input": {
    "mode": "image-to-image",
    "prompt": "keep the product shape, change the scene to a premium studio setup",
    "image_urls": [
      "https://example.com/reference-product.jpg"
    ],
    "resolution": "2K",
    "aspect_ratio": "4:3",
    "output_format": "png"
  }
}

Explicit size

{
  "input": {
    "mode": "text-to-image",
    "prompt": "a minimalist industrial poster with strong geometric composition",
    "size": "2048x2048",
    "output_format": "jpeg"
  }
}

Parameters

request_type · string · default: "async"

Result delivery mode. Use async for polling with statusTask, or callback for webhook delivery.

callback_url · string

Required when request_type is callback. Must be a public HTTPS URL that can receive the final task payload. See Webhooks.

input · object · required

Seedream 5.0 Pro input parameters.

Show properties

mode · string · required

Generation mode. Supported values: text-to-image, image-to-image.

prompt · string · required

Text prompt describing the desired image. Supports 1-5000 characters after trimming whitespace.

image_urls · string[]

Reference image URLs. Required for image-to-image. Accepts 1-10 public image URLs. Each URL must be reachable by APIXO during task submission.

resolution · string · default: "1K"

Output resolution tier. Supported values: 1K, 2K. When either resolution or aspect_ratio is provided, Seedream 5.0 Pro uses the resolution + aspect_ratio preset path; missing values default to 1K and 1:1.

aspect_ratio · string · default: "1:1"

Output aspect ratio. Supported values: 1:1, 2:3, 3:2, 4:3, 3:4, 9:16, 16:9, 21:9. When resolution + aspect_ratio and size are both provided, resolution + aspect_ratio takes precedence.

size · string

Optional explicit size or preset token. Preset tokens support 1K and 2K. Pixel strings accept x, X, or * separators, such as 1024x1024, 2048X2048, or 2048*2048. Custom pixel sizes must use 16-pixel granularity, keep aspect ratio between 1/16 and 16, and keep total pixels between 921,600 and 4,194,304 (1280x720 to 2048x2048 equivalent). Invalid custom values are rejected instead of auto-adjusted.

output_format · string · default: "jpeg"

Output image format. Supported values: jpeg, png.

nsfw_checker · boolean · default: "false"

Enables content safety filtering for this request. Defaults to false. Must be a boolean when provided.

Size presets from resolution + aspect_ratio

When resolution or aspect_ratio is provided, Seedream 5.0 Pro maps the effective resolution + aspect_ratio pair to these output dimensions:

Aspect ratio	1K size	2K size
1:1	1024x1024	2048x2048
4:3	1152x864	2304x1728
3:4	864x1152	1728x2304
16:9	1312x736	2848x1600
9:16	736x1312	1600x2848
3:2	1248x832	2496x1664
2:3	832x1248	1664x2496
21:9	1568x672	3024x1296

Response format

Submit task response

POST /generateTask/seedream-5-0-pro returns a task ID when the task is accepted:

code · integer

API status code. 200 means the task was accepted.

message · string

Human-readable status message.

data.taskId · string

Task identifier used for later polling or webhook matching.

Latency and polling

Seedream 5.0 Pro tasks are asynchronous.

Output tier	Typical generation time	Recommended first poll	Poll interval
1K	20s-35s	20s after task creation	3s
2K	25s-50s	20s after task creation	3s

For production systems, prefer callback_url instead of tight polling loops.

Billing

Seedream 5.0 Pro is billed per request because each task returns exactly one output image.

Unit	APIXO price
Output up to and including 2.36M pixels	$0.045 / request
Output above 2.36M pixels	$0.09 / request
Additional input reference image after the first	$0.003 / image

Billing behavior:

output_charge = 1 * selected output pixel tier price
reference_charge = max(0, reference_image_count - 1) * 0.003
final charge = output_charge + reference_charge

Failed generations are refunded.

Practical notes

• Image-count fields are intentionally omitted from this public contract; Seedream 5.0 Pro returns exactly one image per task.
• 3K and 4K are not supported by this endpoint.
• 2K + 21:9 maps to 3024x1296, which preserves the 21:9 ratio while staying within the 4,194,304 pixel limit.
• If resolution or aspect_ratio is provided together with size, the effective resolution + aspect_ratio preset decides the output dimensions.
• If you only provide size, APIXO uses that explicit pixel size or preset token.

Related links

• Image Models
• Generation API Overview
• Generate Task
• Status Task
• Webhooks
• Error Codes
• Try Seedream 5.0 Pro in the APIXO Playground
• Pricing