LeClap
A deterministic video composition library driven by a single JSON template, rendering the same result on Node, in the browser through WebAssembly, or fully on-device in a React Native app, with no server or generative model.
LeClap renders a video from one JSON template describing its sections, filters, music and overlays, and that same template produces the same composition whether it runs on Node, in a browser through WebAssembly, or natively on a phone through React Native with FFmpeg linked directly into the app. Because nothing is generated or sampled, the same input reliably produces the same output on a given platform, unlike cloud rendering APIs or purely generative video tools.
It positions itself against tools such as Remotion, which needs a browser engine to render even though it needs no server, and cloud renderers such as Shotstack, which always call out to an API. LeClap can also be authored and driven by an AI agent over the Model Context Protocol, in addition to being composed by hand, and the project publishes a detailed comparison of its tradeoffs against Remotion for choosing between them.