ByteDance

This page adapts the original AI SDK documentation: ByteDance.

The ByteDance provider contains support for the Seedance family of video generation models through the BytePlus ModelArk platform. Seedance provides high-quality text-to-video and image-to-video generation capabilities, including audio-video synchronization, first-and-last frame control, and multi-reference image generation.

Setup

The ByteDance provider is available in the ByteDanceProvider module. Add it to your Swift package:

// Package.swift (excerpt)
dependencies: [
  .package(url: "https://github.com/teunlao/swift-ai-sdk", from: "0.17.5")
],
targets: [
  .target(
    name: "YourTarget",
    dependencies: [
      .product(name: "SwiftAISDK", package: "swift-ai-sdk"),
      .product(name: "ByteDanceProvider", package: "swift-ai-sdk")
    ]
  )
]

Provider Instance

You can import the default provider instance byteDance from ByteDanceProvider:

import SwiftAISDK
import ByteDanceProvider

let model = byteDance.video("seedance-1-0-pro-250528")

If you need a customized setup, you can use createByteDance and create a provider instance with your settings:

import ByteDanceProvider

let byteDance = createByteDance(settings: ByteDanceProviderSettings(
  apiKey: "your-api-key", // optional, defaults to ARK_API_KEY
  baseURL: "custom-url",  // optional
  headers: [
    "X-Custom-Header": "value"
  ] // optional
))

You can use the following optional settings to customize the ByteDance provider instance:

• baseURL String

  Use a different URL prefix for API calls, e.g. to use proxy servers. The default prefix is https://ark.ap-southeast.bytepluses.com/api/v3.

• apiKey String

  API key that is being sent using the Authorization header. It defaults to the ARK_API_KEY environment variable. You can obtain an API key from the BytePlus console.

• headers [String: String]

  Custom headers to include in the requests.

• fetch FetchFunction

  Custom fetch implementation. You can use it as a middleware to intercept requests, or to provide a custom fetch implementation for e.g. testing.

Video Models

You can create ByteDance video models using the .video() factory method. For more on video generation with the Swift AI SDK see Video Generation.

Text-to-Video

Generate videos from text prompts:

import SwiftAISDK
import ByteDanceProvider
import Foundation

let result = try await experimental_generateVideo(
  model: byteDance.video("seedance-1-0-pro-250528"),
  prompt: "Photorealistic style: Under a clear blue sky, a vast expanse of white daisy fields stretches out. The camera gradually zooms in and fixates on a close-up of a single daisy.",
  aspectRatio: "16:9",
  duration: 5,
  providerOptions: ["bytedance": [
    "watermark": false
  ]]
)

try result.video.data.write(to: URL(fileURLWithPath: "video.mp4"))

Image-to-Video

Generate videos from a first-frame image with an optional text prompt:

import SwiftAISDK
import ByteDanceProvider
import Foundation

let result = try await experimental_generateVideo(
  model: byteDance.video("seedance-1-5-pro-251215"),
  prompt: .imageToVideo(
    image: .string("https://example.com/first-frame.png"),
    text: "The cat slowly turns its head and blinks"
  ),
  duration: 5,
  providerOptions: ["bytedance": [
    "watermark": false
  ]]
)

try result.video.data.write(to: URL(fileURLWithPath: "video.mp4"))

Image-to-Video with Audio

Seedance 1.5 Pro supports generating synchronized audio alongside the video:

import SwiftAISDK
import ByteDanceProvider
import Foundation

let result = try await experimental_generateVideo(
  model: byteDance.video("seedance-1-5-pro-251215"),
  prompt: .imageToVideo(
    image: .string("https://example.com/pianist.png"),
    text: "A young man sits at a piano, playing calmly. Gentle piano music plays in sync with his movements."
  ),
  duration: 5,
  providerOptions: ["bytedance": [
    "generateAudio": true,
    "watermark": false
  ]]
)

try result.video.data.write(to: URL(fileURLWithPath: "video.mp4"))

First-and-Last Frame Video

Generate smooth transitions between a starting and ending keyframe image:

import SwiftAISDK
import ByteDanceProvider
import Foundation

let result = try await experimental_generateVideo(
  model: byteDance.video("seedance-1-5-pro-251215"),
  prompt: .imageToVideo(
    image: .string("https://example.com/first-frame.jpg"),
    text: "Create a 360-degree orbiting camera shot based on this photo"
  ),
  duration: 5,
  providerOptions: ["bytedance": [
    "lastFrameImage": "https://example.com/last-frame.jpg",
    "generateAudio": true,
    "watermark": false
  ]]
)

try result.video.data.write(to: URL(fileURLWithPath: "video.mp4"))

Multi-Reference Image-to-Video

Using the Seedance 1.0 Lite I2V model, you can provide multiple reference images (1-4) that the model uses to faithfully reproduce object shapes, colors, and textures:

import SwiftAISDK
import ByteDanceProvider
import Foundation

let result = try await experimental_generateVideo(
  model: byteDance.video("seedance-1-0-lite-i2v-250428"),
  prompt: "A boy wearing glasses and a blue T-shirt from [Image 1] and a corgi dog from [Image 2], sitting on the lawn from [Image 3], in 3D cartoon style",
  aspectRatio: "16:9",
  duration: 5,
  providerOptions: ["bytedance": [
    "referenceImages": [
      "https://example.com/boy.png",
      "https://example.com/corgi.png",
      "https://example.com/lawn.png"
    ],
    "watermark": false
  ]]
)

try result.video.data.write(to: URL(fileURLWithPath: "video.mp4"))

Video Provider Options

The following provider options are available via providerOptions["bytedance"]:

Generation Options

• watermark boolean

  Whether to add a watermark to the generated video.

• generateAudio boolean

  Whether to generate synchronized audio for the video. Only supported by Seedance 1.5 Pro.

• cameraFixed boolean

  Whether to fix the camera during generation.

• returnLastFrame boolean

  Whether to return the last frame of the generated video. Useful for chaining consecutive videos.

• serviceTier ‘default’ | ‘flex’

  Inference tier. 'default' for online inference. 'flex' for offline inference at 50% of the price, with higher latency (response times on the order of hours).

• draft boolean

  Enable draft sample mode for low-cost preview generation. Only supported by Seedance 1.5 Pro. Generates a 480p preview video for rapid iteration before committing to a full-quality generation.

Image Input Options

• lastFrameImage string

  URL of the last frame image for first-and-last frame video generation. The model generates smooth transitions between the first frame (provided via the image prompt) and this last frame. Supported by Seedance 1.5 Pro, 1.0 Pro, and 1.0 Lite I2V.

• referenceImages string[]

  Array of reference image URLs (1-4 images) for multi-reference image-to-video generation. The model extracts key features from each image and reproduces them in the video. Use [Image 1], [Image 2], etc. in your prompt to reference specific images. Supported by Seedance 1.0 Lite I2V.

Polling Options

• pollIntervalMs number

  Control how frequently the API is checked for completed videos while they are being processed. Defaults to 3000ms.

• pollTimeoutMs number

  Maximum time to wait for video generation to complete before timing out. Defaults to 300000ms (5 minutes).

Note

Video generation is an asynchronous process that can take several minutes. Consider setting pollTimeoutMs to at least 10 minutes (600000ms) for reliable operation.

Video Model Capabilities

Model	Model ID	Capabilities
Seedance 1.5 Pro	seedance-1-5-pro-251215	T2V, I2V (first frame), I2V (first+last frame), audio-video sync, draft mode. Duration: 4-12s. Resolution: 480p, 720p, 1080p.
Seedance 1.0 Pro	seedance-1-0-pro-250528	T2V, I2V (first frame), I2V (first+last frame). Duration: 2-12s. Resolution: 480p, 720p, 1080p.
Seedance 1.0 Pro Fast	seedance-1-0-pro-fast-251015	T2V, I2V (first frame). Optimized for speed and cost. Duration: 2-12s.
Seedance 1.0 Lite (T2V)	seedance-1-0-lite-t2v-250428	Text-to-video only. Duration: 2-12s. Resolution: 480p, 720p, 1080p.
Seedance 1.0 Lite (I2V)	seedance-1-0-lite-i2v-250428	I2V (first frame), I2V (first+last frame), multi-reference images (1-4). Duration: 2-12s. Resolution: 480p, 720p.

Supported aspect ratios: 16:9, 4:3, 1:1, 3:4, 9:16, 21:9, adaptive (image-to-video only).

All models output MP4 video at 24 fps.

Note

You can also pass any model ID string if needed, e.g. for future models not yet listed here.