MasterPlayspots/motionspec

**MotionSpec is an MCP server and CLI for web animation accessibility.** It helps AI coding agents and frontend developers compile validated animation specs to deterministic **GSAP + CSS** and find motion-accessibility candidates in a page's loaded CSS: missing prefers-reduced-motion guards and missing pause paths for continuous animation.
The MIT compiler includes reduced-motion handling and loop pause controls by default. Its static audit supports review of **WCAG 2.2.2 (Pause, Stop, Hide — Level A)** and **WCAG 2.3.3 (Animation from Interactions — Level AAA)**. Findings need contextual review; a clean scan is not a full accessibility or WCAG-conformance assessment. Runtime JavaScript animation, flashing, video and Canvas are outside the audit's scope.
- **Create web animation:** choose a catalog primitive, validate a JSON spec, then compile vanilla-GSAP JavaScript and CSS. The internal WAAPI lowering is not a public build target.
- **Check CSS motion:** audit a URL for reduced-motion and pause-path candidates, then review the reported selectors and suggested fixes.
- **Prevent regressions:** use the CI example to compare findings against an explicitly accepted baseline.
Local stdio MCP exposes all five tools without an API key (npx -y motionspec). The hosted endpoint at https://api.motionspec.dev/mcp provides keyless motion_catalog and motion_validate; hosted compile, audit and stats require a key. See the installation guide and motion accessibility guide. Docs and product: https://motionspec.dev/docs.
The thesis: **capability lives in the catalog, not the model.** A bigger model can write more elaborate specs, but it can never emit a primitive, parameter, or selector the Trust Boundary hasn't approved. The compiler trusts only what passes.
Not to be confused with
> **Not to be confused with:** the Android Material Components MotionSpec class, the iOS material-motion MotionSpec, Motion.dev / Framer Motion, the usemotion.com calendar app, the Motion Specialties mobility brand, or text-to-video generators (Runway/Sora/Kling/Viggle). MotionSpec checks the *UI animation inside web apps* — it does not generate video.
60-second start
The host LLM authors the spec; the Trust Boundary stays enforced either way. Listed on the MCP Registry as io.github.MasterPlayspots/motionspec. A hosted MCP endpoint is live: keyless motion_catalog + motion_validate at https://api.motionspec.dev/mcp (streamable-http; keyed tiers cover compile/audit/stats) — setup: https://motionspec.dev/docs.
Claude Code plugin
This repo is also a Claude Code plugin: it bundles the MCP server (npx motionspec, all five tools, local, keyless) with two skills — /motionspec:motion (the author→validate→compile workflow) and /motionspec:audit (motion-accessibility check, WCAG 2.2.2/2.3.3). Try it directly from a clone with claude --plugin-dir ., or install it from the community marketplace once listed:
Status
| | |
|---|---|
| Version | **v1.2.9** · schema frozen at spec v1 (ADR-0001, signed) |
| Published | **npm motionspec** (105 kB packed, 67 files, nothing dev-only ships) · MCP Registry |
| Tests | **360 green** — injection attacks, 6000-spec fuzz, golden determinism, schema parity, pause-controls, motion-a11y audit · CI on Node 18/20/22 + x86 Playwright e2e |
| Catalog | **40 primitives**, every one device-verified, reduced-motion-fallback mandatory; the 18 continuous loops also carry a WCAG-2.2.2 pause path |
| Supply chain | **2 runtime deps** (MCP SDK, zod — both pinned) · 0 vulnerabilities · CycloneDX SBOM regenerated and checked in CI · all permissive licenses · CI actions SHA-pinned |
| Coverage | 97.23% lines / 95.17% functions / 80.82% branches of src/ (npm run coverage, 2026-10-08; CI gate 90/90/75) |
| Last audit | 2026-07-03 — 17/17 integration handshakes evidenced, infra 8.1/10, security: **0 critical**, full-git-history secret scan clean |