decart

Decart

Decart is an AI video/image platform centered on realtime transformation, with three APIs: Realtime (WebRTC, sub-500ms), Queue (async batch video generation/editing), and Process (sync image generation/editing). SDKs for JavaScript, Python, Android, and Swift. Auth via API key from platform.decart.ai — set DECART_API_KEY env var. Docs: https://docs.platform.decart.ai

When to use

• Realtime video transformation — camera effects, video conferencing filters, AR/VR overlays, photo booths, live streaming
• Batch video generation — marketing clips, social content, product demos, and animations from text or images
• Batch video editing — edit existing videos with text prompts, reference images, or both
• Video restyling — apply artistic styles to live streams or existing videos
• Image generation/editing — mockups, thumbnails, creative assets, and image-to-image transformation
• Character transformation — transform user's live camera feed into characters (anime, fantasy, etc.)
• Framework integration — Vercel AI SDK, TanStack AI, LangChain.js all supported

API selection

You want to...	API	Method	Best for
Transform live camera/video	Realtime	client.realtime.connect()	Interactive apps, below 500ms latency
Restyle live video with artistic styles	Realtime	client.realtime.connect()	Live style transfer
Edit existing video	Queue	client.queue.submitAndPoll()	Video transformation, unlimited duration
Restyle existing video	Queue	client.queue.submitAndPoll()	Batch style transfer
Edit an image	Process	client.process()	Sync results, thumbnails

Model selection

Use case	Model	Type
Character transform live	lucy-2.5	Realtime
Artistic style transfer live	lucy-restyle-2	Realtime
Virtual try-on (live or batch)	lucy-vton-3.5	Realtime + Batch
Lowest-latency live editing / try-on (2x rate)	lucy-2.5 or lucy-vton-3.5 + speed: "fast"	Realtime
Video editing (best quality)	lucy-2.5	Batch
Video restyling	lucy-restyle-2	Batch
Image editing	lucy-image-2	Process

Quick start patterns

Realtime (connect + transform)

const model = models.realtime("lucy-2.5");
const stream = await navigator.mediaDevices.getUserMedia({
  video: { frameRate: model.fps, width: model.width, height: model.height }
});
const rt = await client.realtime.connect(stream, {
  model,
  mirror: "auto", // pre-flip front-camera input so server-baked pixels render correctly
  onRemoteStream: (s) => { videoEl.srcObject = s; }
});
await rt.set({ prompt: "Transform into anime character", image: refImage, enhance: true });

Queue (video editing)

const result = await client.queue.submitAndPoll({
  model: models.video("lucy-2.5"),
  data: videoFile,
  prompt: "Transform into anime style",
  resolution: "720p",
});

Process (image editing)

const image = await client.process({
  model: models.image("lucy-image-2"),
  data: imageFile,
  prompt: "Change the background to a beach",
  resolution: "720p",
});

Authentication

• Server-side: Set DECART_API_KEY env var. The SDK picks it up automatically.
• Client-side: Generate short-lived tokens on your backend via client.tokens.create(), then send token.apiKey to the frontend.
• Token options: expiresIn (1–3600s, default 60s), allowedModels (restrict model access), allowedOrigins (pin to canonical web origins, browser-enforced), constraints (e.g. realtime.maxSessionDuration).
• NEVER expose permanent API keys in browser or mobile code.

Camera constraints

Always use model.fps, model.width, model.height from the SDK to avoid scaling artifacts.

Pass resolution: "1080p" to realtime.connect() (or the SDK equivalent) when you need a 1080p remote stream; defaults to 720p.

Boundaries

What agents CAN do

• Generate integration code for all three APIs (Realtime, Queue, Process)
• Help select models, configure SDK, set up authentication
• Write WebRTC realtime streaming code
• Build framework integrations (Vercel AI SDK, TanStack AI, LangChain.js)
• Troubleshoot connection, moderation, and billing issues

What agents CANNOT do

• Create or manage Decart accounts, API keys, or billing
• Access the Decart dashboard or platform settings
• Test realtime connections (requires actual WebRTC + camera)
• Verify credit balance or usage
• Bypass content moderation policies

Common gotchas

• NEVER expose permanent API keys in client code. Use client tokens for browser/mobile, and pass allowedOrigins so a leaked token can't be replayed from another web origin.
• ALWAYS use model.fps, model.width, model.height for camera constraints. Mismatched resolution causes latency and artifacts.
• ALWAYS call disconnect() and stop media tracks when done. Leaving connections open causes memory leaks and billing.
• Catch errors from set(), setPrompt(), setImage(). Moderation rejections throw here.
• Listen to connectionChange events. The SDK auto-reconnects, but your UI must reflect the state.
• Keep enhance: true (default) unless you need exact prompt control.
• Use submitAndPoll() for queue jobs. Don't manually poll faster than every 2 seconds.
• Image editing (i2i) only works with Process API, not Queue API. Queue is for video only.
• Realtime sessions end silently when credits run out. Listen for disconnect events.
• For Lucy 2.5 character transform, use clear portrait photos with good lighting.
• Lucy Clip (lucy-clip) is legacy with a 5-second clip limit. Use lucy-2.5 for new projects (unlimited duration).
• lucy-2.5 accepts a reference image, a text prompt, or both together for maximum control.
• Use mirror: "auto" on realtime.connect() for selfie streams instead of CSS-flipping the displayed video.
• Fast mode (speed: "fast" on realtime.connect()) is billed at 2x the standard realtime rate, and applies only to lucy-2.5/lucy-latest and lucy-vton-3.5/lucy-vton-latest; other models silently ignore it. Omit the option for standard mode — never send speed: "standard". Requires @decartai/sdk v0.2.2+ (earlier versions: queryParams: { speed: "fast" }).

Verification checklist

• API key stored in environment variable, never hardcoded
• Client tokens generated on backend for any browser/mobile realtime usage
• Camera resolution matches model's fps, width, height constraints
• Error handlers on set(), setPrompt(), setImage() calls
• connectionChange listener updates UI on disconnect/reconnect
• disconnect() called and media streams stopped on cleanup
• enhance: true enabled unless exact prompt control needed
• Queue API for video editing, Process API for images
• Moderation errors caught and shown to user gracefully
• Tested on real device for mobile (simulator lacks WebRTC)

Resources

• Full docs navigation: https://docs.platform.decart.ai/llms.txt
• Models overview: https://docs.platform.decart.ai/getting-started/models
• Realtime best practices: https://docs.platform.decart.ai/models/realtime/streaming-best-practices
• JavaScript SDK: https://docs.platform.decart.ai/sdks/javascript-realtime
• Android SDK: https://docs.platform.decart.ai/sdks/android