Product launch · XiaoHu Explains

Decart ships Lucy 2.5: edit video while it streams, latency claimed under 40ms

Add objects, swap backgrounds, run effects live. The product page cites sub-40ms latency and 100FPS continuous generation. Try it at lucy.decart.ai.

One-minute brief
  • Decart released Lucy 2.5 for realtime video editing: while the feed is still playing, you can add, swap, or remove content, reshape scenes, and run effects.
  • Version 2.5 brings two upgrades: more realistic frames and tighter prompt following.
  • On the product page: sub-40ms latency (under 40 milliseconds), 100fps continuous generation, and 4x realtime inference.
  • Use cases include ecommerce virtual try-on and livestream shopping, interactive streams, ad variants, and live product placement.
  • Try it: lucy.decart.ai; product page: decart.ai/lucy
⚑ Caveat: the capabilities, speed figures, and use-case claims below come mainly from Decart’s official posts and product page. They are vendor claims, not third-party benchmarks.
1Launch

Decart just shipped Lucy 2.5

On July 17, 2026, AI company Decart announced Lucy 2.5 on X. The company calls it its strongest realtime model yet.

In one line: Lucy can rewrite the picture while the video is still playing and still being generated. You don’t wait for a full render, then open a NLE and cut frame by frame.

Most AI video tools still generate first, export later. Lucy’s pitch is frame-level edits in the live path: while the audience is watching, clothes, backgrounds, or effects already change on screen.
Hero demo from the product site. Source: decart.ai/lucy
First demo from the launch thread. Source: Decart’s official X
2Capabilities

What you can actually change on screen

Four core moves: add, swap, remove, and run effects.

What Lucy 2.5 stresses over prior versions

Higher realism and visual fidelity; better prompt adherence (when you ask for a change, it tracks closer).

Objects & characters
Add, swap, remove
Swap characters, insert people; replace, add, or remove objects; tweak attributes such as color and look.
Scenes
Background & style
Change the backdrop, shift the overall look, and reshape the live scene into something else.
Effects
Realtime VFX
Generate visual effects while the stream runs—no overnight pass in a VFX suite first.
Positioning
Programmable video
Treat video as a programmable medium: people, products, environments, and effects can change on the fly.
Camera / stream Live feed Lucy live edit Add / swap / remove / VFX Viewer Sees edited video
Sketch: the stream keeps running; edits already hit the current frame
Second post: add, replace, remove, and live effects. Source: Decart’s official X
How this differs from classic editing

Classic path: record → import → fix frame by frame → export and ship. Lucy aims for the opposite: while the stream is still live, a prompt or instruction already rewrites the current frame—more like swapping props on set mid-show than sending the tape back to the edit bay.

3Speed

What counts as “realtime”

Inference runs on Decart’s own DOS stack. The numbers below come from the product page, not our own benchmarks.

<40ms
Latency: edits appear before the frame completes
100FPS
Continuous generation frame rate
4x
Realtime inference speed
30x
More frames per second vs. comparable systems

Elsewhere in the FAQ you also see figures like “within 200 milliseconds, 22FPS (512×768).” Those sit in a different section from the headline sub-40ms / 100FPS claims. The public pages don’t spell out how the two measurement setups differ. Keep this in mind: the lead marketing numbers are sub-40ms and 100FPS; end-to-end feel is whatever your own trial shows.

Lucy runs on Decart’s DOS. The company describes it as in-house inference and training infrastructure built for realtime workloads—the stack behind those latency and frame-rate claims.

4Use cases

Where it fits

Three main lanes: ecommerce, livestreaming, and ads. There are also social and gaming demos.

Ecommerce
Virtual try-on, live shopping
While the host is still talking, outfits, shelves, or backdrops can change on the spot.
Livestream
Interactive streams, viewer-driven moments
Votes or commands can drive visual changes—not just chat noise in the sidebar.
Ads
Ad variants, live product placement
Spin multiple versions from one asset in the moment; drop products into a live stream on demand.
More
Social, gaming
Creator and digital-world extensions, with social and gaming demos on the site.
Ecommerce / shopping demo. Source: decart.ai
Streaming / live demo. Source: decart.ai
Advertising demo. Source: decart.ai
Third post: industry reel. Source: Decart’s official X

LOOOK.AI founder Dmytro Kornilov, roughly: Decart’s SDK can deliver realtime consumer experiences on the retail floor without tanking quality. That’s partner endorsement, not an independent lab report.

5Try it

How to try it

The company calls Lucy the only realtime video model and points to a try link. That’s their own positioning line.

🧰 Quick start · Lucy 2.5
AccessOpen the try page to start; enterprise deals go through the site contact form

Official posts also say pricing will keep moving lower, but this launch doesn’t lock in package prices. Treat the try page and sales conversations as the source of truth on cost.

Meet Lucy 2.5, our most advanced realtime model yet. Lucy edits video in real time, now with more power and control. Decart official X, 2026-07-17

Primary sources: Decart launch thread (2026-07-17); product page decart.ai/lucy; try link lucy.decart.ai. Capabilities, latency, frame rates, and industry claims all come from vendor materials. The FAQ also mentions 200ms / 22FPS, without clarifying whether that setup matches the headline sub-40ms / 100FPS numbers.