From zero to live AI video

npm install @decartai/sdk

pip install decart

// settings.gradle.kts — add the JitPack repository
dependencyResolutionManagement {
    repositories {
        google()
        mavenCentral()
        maven { url = uri("https://jitpack.io") }
    }
}

// app build.gradle.kts — add the dependency
dependencies {
    implementation("com.github.DecartAI:decart-android:0.2.0")
}

import { createDecartClient, models } from "@decartai/sdk";

const model = models.realtime("lucy-2.5");

// 1. Capture the camera at the model's native format
const stream = await navigator.mediaDevices.getUserMedia({
  video: {
    frameRate: model.fps,
    width: model.width,
    height: model.height,
  },
});

// 2. Create a client and connect — the edited stream comes back via callback
const client = createDecartClient({
  apiKey: "your-api-key-here",
});

const realtimeClient = await client.realtime.connect(stream, {
  model,
  mirror: "auto",
  onRemoteStream: (transformedStream) => {
    document.getElementById("output").srcObject = transformedStream;
  },
  // Pass the first edit here so the very first frame is already transformed
  initialState: {
    prompt: {
      text: "Change the wall's color to light blue, natural consistent paint finish.",
      enhance: true,
    },
  },
});

// 3. Edit the live stream at any time
await realtimeClient.set({
  prompt: "Substitute the character in the video with the person in the reference image.",
  image: characterImage,
  enhance: true,
});

import asyncio
from decart import DecartClient, models
from decart.types import ModelState, Prompt

async def main():
    async with DecartClient(api_key="your-api-key-here") as client:
        model = models.realtime("lucy-2.5")

        realtime = await client.realtime.connect(
            stream=media_stream,
            model=model,
            on_remote_stream=lambda s: display(s),
            initial_state=ModelState(
                prompt=Prompt(
                    text="Change the wall's color to light blue, natural consistent paint finish.",
                    enhance=True,
                ),
            ),
        )

        with open("character.jpg", "rb") as f:
            await realtime.set(
                prompt="Substitute the character in the video with the person in the reference image.",
                image=f,
                enhance=True,
            )

asyncio.run(main())

// Change to a new character
await realtimeClient.set({
  prompt: "Substitute the character in the video with the person in the reference image.",
  image: newCharacterImage,
  enhance: true,
});

// Set a new image only (clears any previous prompt)
await realtimeClient.set({ image: newCharacterImage });

// Set a new prompt only (clears any previous image)
await realtimeClient.set({ prompt: "Add dark sunglasses to the person's face." });

// Clear the reference image (fall back to text-only editing)
await realtimeClient.set({ image: null });

# Change to a new character
with open("new_character.jpg", "rb") as f:
    await realtime.set(
        prompt="Substitute the character in the video with the person in the reference image.",
        image=f,
        enhance=True,
    )

# Set a new image only (clears any previous prompt)
with open("another.jpg", "rb") as f:
    await realtime.set(image=f)

# Set a new prompt only (clears any previous image)
await realtime.set(prompt="Add dark sunglasses to the person's face.")

// Text-only edit — update the prompt mid-session, no reconnect needed
await realtimeClient.set({
  prompt: "Substitute the character in the video with a futuristic robot.",
  enhance: true, // Lucy expands terse prompts into rich visual direction
});

// Prompt + reference image — tell Lucy what to take from the image
await realtimeClient.set({
  prompt: "Substitute the character in the video with the warrior from the attached image.",
  image: referenceImage, // File | Blob
  enhance: true,
});

# Text-only edit — update the prompt mid-session, no reconnect needed
await realtime.set(
    prompt="Substitute the character in the video with a futuristic robot.",
    enhance=True,
)

# Prompt + reference image — tell Lucy what to take from the image
with open("warrior.jpg", "rb") as f:
    await realtime.set(
        prompt="Substitute the character in the video with the warrior from the attached image.",
        image=f,
        enhance=True,
    )

# Scaffold a tiny Vite app and add the SDK
npm create vite@latest my-lucy-demo -- --template vanilla
cd my-lucy-demo
npm install @decartai/sdk

# Add your key (from step 03)
echo "VITE_DECART_API_KEY=your-api-key-here" > .env.local

# Replace index.html and main.js with the two files below, then:
npm run dev

<!doctype html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>My Lucy Demo</title>
    <style>
      body { margin: 0; min-height: 100vh; box-sizing: border-box; display: flex; flex-direction: column; gap: 16px; padding: 24px; font-family: system-ui, sans-serif; background: #fff; }
      .videos { display: flex; gap: 12px; flex: 1; }
      .videos video { width: 50%; aspect-ratio: 16 / 9; object-fit: cover; border-radius: 20px; background: #f9f9f9; }
      #input-video { transform: scaleX(-1); } /* mirror the camera preview */
      #prompt-form { display: flex; gap: 8px; width: 100%; max-width: 702px; margin: 0 auto; }
      #prompt { flex: 1; height: 48px; border: 1px solid #e2e2e2; border-radius: 999px; padding: 0 20px; font-size: 16px; outline-color: #2548f6; }
      #prompt-form button { height: 48px; padding: 0 24px; border: 0; border-radius: 999px; background: #2548f6; color: #fff; font-size: 16px; cursor: pointer; }
    </style>
  </head>
  <body>
    <div class="videos">
      <video id="input-video" autoplay playsinline muted></video>
      <video id="output-video" autoplay playsinline muted></video>
    </div>
    <form id="prompt-form">
      <input id="prompt" placeholder="Describe your edit — try: Add a black top hat on top of my head." autocomplete="off" />
      <button type="submit">Send</button>
    </form>
    <script type="module" src="/main.js"></script>
  </body>
</html>

import { createDecartClient, models } from "@decartai/sdk";

const model = models.realtime("lucy-2.5");

// 1. Camera in — ask for the model's native format
const stream = await navigator.mediaDevices.getUserMedia({
  video: { frameRate: model.fps, width: model.width, height: model.height },
});
document.getElementById("input-video").srcObject = stream;

// 2. Connect — Lucy's edited stream comes back through onRemoteStream
const client = createDecartClient({
  apiKey: import.meta.env.VITE_DECART_API_KEY, // fine for local dev; see note below
});

const realtimeClient = await client.realtime.connect(stream, {
  model,
  mirror: "auto",
  onRemoteStream: (transformedStream) => {
    document.getElementById("output-video").srcObject = transformedStream;
  },
  initialState: {
    prompt: { text: "Restyle to animated movie", enhance: true },
  },
});

// 3. The prompt line — every submit becomes a live edit
document.getElementById("prompt-form").addEventListener("submit", async (event) => {
  event.preventDefault();
  const text = document.getElementById("prompt").value.trim();
  if (text) {
    await realtimeClient.set({ prompt: text, enhance: true });
  }
});

// Tidy up when the tab closes
window.addEventListener("beforeunload", () => {
  realtimeClient.disconnect();
  stream.getTracks().forEach((track) => track.stop());
});