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Decart provides real-time AI video transformation with style transfer and virtual try-on. Transform video streams into animated styles, apply reference-image costumes, or any custom prompt-based visual effect using models like Lucy.
Vision Agents uses Stream Video for real-time WebRTC transport by default. External WebRTC transports are supported as well. Most AI providers offer free tiers to get started.

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Installation

uv add "vision-agents[decart]"

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Quick start

from vision_agents.core import Agent, User
from vision_agents.plugins import decart, gemini, deepgram, elevenlabs, getstream

processor = decart.RestylingProcessor(
    initial_prompt="Studio Ghibli animation style",
    model="lucy_2_rt",
)

agent = Agent(
    edge=getstream.Edge(),
    agent_user=User(name="Styled AI"),
    instructions="Be helpful",
    llm=gemini.Realtime(),
    stt=deepgram.STT(),
    tts=elevenlabs.TTS(),
    processors=[processor],
)
Set DECART_API_KEY in your environment or pass api_key directly.

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Parameters

NameTypeDefaultDescription
modelstr"lucy_2_rt"Decart model
initial_promptstr"Cyberpunk city"Style prompt for visual transformation
initial_imagebytes | str | PathNoneOptional reference image for first connect (bytes, file path, http(s) URL, data URI, or raw base64)
enhanceboolTrueWhether to enhance the prompt
mirrorboolTrueMirror mode for front-facing cameras
widthint1280Output video width
heightint720Output video height
api_keystrNoneAPI key (defaults to DECART_API_KEY env var)

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Dynamic style changes

Update the video style during a call via function calling: 
@llm.register_function(description="Changes the video style")
async def change_style(prompt: str) -> str:
    await processor.update_prompt(prompt)
    return f"Style changed to: {prompt}"

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Reference images

For models like Lucy that accept a reference image, pass it at construction time and/or swap it atomically with a prompt using update_state: 
processor = decart.RestylingProcessor(
    model="lucy_2_rt",
    initial_prompt="A person wearing a superhero costume",
    initial_image="./costumes/superhero.png",
)

# Atomically change prompt + reference image
await processor.update_state(
    prompt="A person wearing a wizard robe",
    image="./costumes/wizard.png",
)

# Image-only update
await processor.update_state(image=b"<raw image bytes>")
initial_image and update_state(image=...) accept bytes, a local file path, an http(s) URL, a data: URI, or a raw base64 string.

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Next steps

Build a Voice Agent

Get started with voice

Build a Video Agent

Add video processing