Changelog.

v4.0 “Volta” — physics-based easing, timeline scrubbing, smaller bundles.

Four months in the oven, 312 commits, and a long list of refinements suggested on the public roadmap. The headline of this release is a new family of easing primitives: spring, inertia, and decay now sit alongside the classic cubic and quartic curves, and they compile down to the same 60fps-friendly animation worklets we’ve shipped since v2.

What’s in the box

Physics easing was the most-requested feature across our GitHub Discussions and the public roadmap — 1,184 thumbs-up, six independent community PRs offering early implementations, and a long thread debating whether we should ship Verlet or PBD. We went with a small, predictable solver tuned for UI work: bounded oscillation, configurable stiffness and damping, and a hard cap on iterations so the runtime can never stall a frame.

Scene-graph syntax has been refined in parallel. The compiler now folds adjacent transforms, hoists constant interpolations, and emits a timeline that the runtime can scrub forwards and backwards — including on WebGPU, which remains an optional, progressive path. Timeline scrubbing is the first piece of the engine to land native WebGPU support without any shader authoring required from you.

Smaller bundles, not bigger

Volta adds three primitives and zero kilobytes to the median build. Our Q1 2024 audit across 1,420 customer builds puts the median bundle at 14.6KB gzipped, down from 16.1KB in v3.6. The work happened in the compiler: better dead-code elimination, narrower surface for the easing module, and a smaller default theme. If you were already importing only the curves you used, the win is roughly 2KB; if you’re pulling in the full default, the win is closer to 4KB.

scene "hero" {
  node card {
    from: { y: 24, opacity: 0 }
    to:   { y: 0,  opacity: 1 }
    ease: spring(stiffness: 220, damping: 18)
    duration: 640ms
    scrub: true
  }
  node trail {
    from: { scale: 0.96 }
    to:   { scale: 1 }
    ease: decay(friction: 0.42)
    stagger: 60ms
  }
}

Migration & breaking changes

Three small breaking changes — all surfaced on the roadmap six weeks before release, with migration notes:

• timeline.seek() now returns a Promise<TimelineState> for parity with the new scrub API. Add await or drop the return value if you weren’t using it.
• The deprecated legacy.bundle entrypoint was removed. If your bundler still references it, switch to codeanimato/runtime.
• The default easing for declarative enter/exit blocks changed from quartic.out to spring(180, 22). Pin a curve explicitly if you need bit-for-bit parity with v3.

— The CodeAnimato core team. File issues on GitHub, send smaller notes to our Discussions board, and watch the roadmap for what we ship next.