@velocut/core-ts

The TypeScript reference engine — a faithful mirror of the canonical Rust engine (crates/velocut-core).

• Role: applies @velocut/protocol commands to the document model and evaluates a time into a FrameGraph. It is the frontend's fallback when the WASM bundle is absent, and is directly runnable on Node.
• Contract: its behavior is pinned to the Rust engine by the shared golden vectors in protocol/vectors/*.json — test/vectors.test.ts runs them here, crates/velocut-core/tests/vectors.rs runs the same set there. A behavioral change must land as a new vector that both sides pass.
• Depends on: @velocut/protocol.

Usage

The npm package ships ESM JavaScript and TypeScript 5.9+ declarations. JavaScript runs directly on Node: node demo.mjs; no TypeScript loader is needed.

import { TsEngine } from '@velocut/core-ts';

const engine = new TsEngine('demo', 1920, 1080, 30, 1);

engine.apply({ type: 'addAsset', kind: 'video', src: 'clip.mp4', name: 'Clip', durationUs: 5_000_000, id: 'asset-1' });
engine.apply({ type: 'addTrack', kind: 'video' });
const trackId = engine.document().tracks[0].id;
engine.apply({ type: 'addClip', trackId, assetId: 'asset-1', startUs: 0, durationUs: 2_000_000 });

const fg = engine.evaluate(1_000_000); // FrameGraph at t = 1s
console.log(fg.layers.length, fg.layers[0].sourceTimeUs); // 1 1000000

See the root README and PROTOCOL.md for the full command set.