This is the dependency layer for all motion work in the ecosystem. It locks down token values (duration, easing, distance, scale), spring presets, and the runtime gates that decide whether an animation should fire at all. The rules are strict: motion/react only, initial must match server output, no layout property animations, prefers-reduced-motion overrides everything. If you're building animated components in Next.js, you load this first to avoid hydration mismatches and accessibility violations. The decision tables for choosing durations and springs are worth the price of admission alone.
npx skills add https://github.com/affaan-m/everything-claude-code --skill motion-foundations