# LongLive-2.0 API

> LongLive-2.0 as a hosted realtime API. A multi-shot clip on main_video; chunk_index resets per scene while session_chunk keeps counting. $0.0021 per billable second.

Source: https://windflow.online/models/longlive-2 · Realtime video generation · Windflow Labs

## What it is

LongLive-2.0 is an autoregressive, multi-shot video diffusion model from NVIDIA Research (NVlabs), built on a Wan2.2-TI2V backbone and designed to keep a long video coherent as the prompt changes. On Windflow you direct it with text shot prompts: switch the shot softly while it runs, or cut to a new scene.

## Specifications

- **Architecture:** Autoregressive multi-shot DiT (Wan2.2-TI2V backbone)
- **Resolution:** 1280 × 704
- **Chunk:** 29 frames
- **Scene budget:** 48 chunks per scene; scene_cut opens a fresh budget
- **Inputs:** Text shot prompts only — no reference image in this release
- **Outputs:** A multi-shot clip on main_video; chunk_index resets per scene while session_chunk keeps counting
- **Delivery:** WebSocket (H.264) · WebRTC
- **Session protocol:** sdk.realtime.v2
- **Price:** $0.0021 per billable second

## Pricing

$0.0021 per billable session-second ($7.56/hr of billable time). Billing starts at the session's first generation_started event and stops when the session is released or ends. Queueing, worker startup, time before generation starts and the documented reconnect grace are not billed. After generation starts, paused or unwatched time remains billable; release the owner session to stop the meter.

## Use cases

- Multi-shot narrative clips directed live, one text prompt per shot.
- Interactive long-form video where a viewer or an agent decides what happens next.
- Storyboard-to-motion experiments that need scene-to-scene continuity.
- Streams directed scene after scene within the session's published duration limits.

## Where it comes from

- [NVlabs/LongLive on GitHub](https://github.com/NVlabs/LongLive) — Apache-2.0

## FAQ

### Does LongLive-2.0 accept a reference image?

Not in this release. It is directed with text shot prompts only; use LTX-2.5 or Helios when you need to start from an image.

### What is the difference between a soft shot change and a scene cut?

A soft change switches the prompt live and keeps the model's rolling history, so the picture evolves. A scene cut starts a new scene and rebuilds that history, which suits independent content.

### Will a soft shot change preserve every object exactly?

No. Retaining rolling history is a conditioning policy, not a guarantee of identity or geometry. Evaluate a repeatable shot sequence and inspect continuity as well as the delay until the new direction becomes visible.

### How should I end a directed stream?

Release the owner session when the experience ends, including error and page-exit paths. Pausing the player does not release model capacity or end billable time after generation has started. Read the session response for its duration limit.

### How much does LongLive-2.0 cost on Windflow?

LongLive-2.0 costs $0.0021 per billable session-second ($7.56/hr of billable time). Billing starts at the session's first generation_started event and stops when the session is released or ends. Queueing, worker startup, time before generation starts and the documented reconnect grace are not billed. After generation starts, paused or unwatched time remains billable; release the owner session to stop the meter. There is no subscription.

### How do I get access to LongLive-2.0?

Windflow is in private beta. Request access from the sign-up page, or ask for a live demo of LongLive-2.0. Approved accounts start with $5 and four concurrent sessions.

### Is LongLive-2.0 always running?

No. Model capacity is brought up on demand rather than kept standing. Live readiness for each model is published at api.windflow.online/v1/status, and a live demo can be arranged on request.

## Related guides

- [Choosing a realtime video model: a decision guide for 12 hosted models](https://windflow.online/guides/choosing-a-realtime-video-model)
- [How to add live AI video to your app and pay per second](https://windflow.online/guides/add-live-ai-video-to-your-app)
- [How to use the LongLive 2 API](https://windflow.online/guides/longlive-2-api)
- [Realtime video API: generate, edit and control live AI video](https://windflow.online/guides/realtime-video-api)
- [Streaming a video diffusion model to the browser: WebRTC or WebSocket?](https://windflow.online/guides/stream-video-diffusion-webrtc-websocket)
- [LongLive 2 prompting guide: shots, cuts and timelines](https://windflow.online/guides/longlive-2-prompting-guide)
- [How realtime video models work: autoregressive diffusion, chunks and the latency budget](https://windflow.online/guides/how-realtime-video-models-work)