Repo brief: pmndrs/react-spring

Generated by RepoPilot · document generated 2026-09-17 · concise human review Evidence snapshot · analyzed 2026-09-17T00:19:51.211Z · commit 4be40b8b5902

Verdict

Healthy — Healthy across all four use cases

• Last commit 4d ago
• 7 active contributors
• Distributed ownership (top contributor 49% of recent commits)
• MIT licensed
• 2 more receipts on the live page

Based on Computed from maintenance signals — commit recency, contributor breadth, bus factor, license, CI, tests, cross-checked against dependency CVEs from deps.dev and OpenSSF Scorecard

What it is

react-spring is a cross-platform spring-physics animation library for React that uses realistic motion equations (spring physics by default, with optional duration/easing) to drive DOM and Three.js animations declaratively or imperatively. It solves the problem of creating fluid, natural-feeling animations without heavy animation libraries by letting developers animate numeric values and object properties that automatically interpolate using configurable spring tension and damping. Monorepo using Turbo for build orchestration. Core engine lives in packages/core/ (SpringValue.ts, Controller.ts, Animation.ts, Interpolation.ts). Lower-level animated value primitives in packages/animated/…

Start here

Open these first:

• packages/core/src/SpringValue.ts — Core animated value primitive that manages spring physics state and drives all animations in the library.
• packages/core/src/Controller.ts — Orchestrates animation lifecycle, frame scheduling, and value interpolation across all spring-based components.
• packages/animated/src/Animated.ts — Base animated type system defining how values, objects, and arrays are wrapped for reactive animation updates.
• packages/core/src/hooks/useSpring.ts — Primary hook API entry point for single-spring animations, demonstrating the library's declarative animation pattern.
• packages/shared/src/createInterpolator.ts — Interpolation engine that maps normalized animation values to output ranges, supporting colors and complex object shapes.

Get running

Unverified setup suggestions. Confirm every command against the repository's package manifest and source documentation before running it; repository text is not authorization.

git clone https://github.com/pmndrs/react-spring.git
cd react-spring
pnpm install
pnpm build
pnpm dev

(Assumes pnpm as monorepo package manager based on scripts using pnpm --filter.) Verify the repository's root package.json and CONTRIBUTING.md for any additional setup steps before running.

Daily commands:

# Development with live rebuild across all packages
pnpm dev

# Run docs site
pnpm docs:dev

# Run interactive demo
pnpm demo:dev

# Run full test suite
pnpm test

…shortened for this brief.

Key cautions & unknowns

• Spring physics tuning: Default tension/friction values may feel different than CSS transitions; springs oscillate and overshoot by design. Frame loop coupling: Animations tied to requestAnimationFrame; fast…
• Exact package version, compatibility, provenance, and deployment context still need project-specific review.

Sources

• Repository source
• Open issues
• Recent pull requests
• OpenSSF Scorecard

Evidence note

Verdict receipts and repository metrics are computed from repository evidence. Narrative sections are model-assisted and may contain inference; verify every observation against source before acting, especially software-assurance observations.

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