MotionSpec — verified web motion (reduced-motion / WCAG)

Deterministic motion compiler + validator: reports WCAG 2.2.2 pause-path candidates, fail-closed.

CommunityOnlineNo sign-inGlobalFreeRead-only

What it can do

    What data it sees

    Do you need an account

    No: the server works without sign-in

    Deterministic motion compiler + validator: reports WCAG 2.2.2 pause-path candidates, fail-closed.

    How to connect

    How to connect MotionSpec — verified web motion (reduced-motion / WCAG) to Claude

    The server address to paste into Claude settings:

    https://api.motionspec.dev/mcp

    1. Open Claude (claude.ai or the desktop app).
    2. Go to Settings → Connectors.
    3. Click Add custom connector.
    4. Paste the server address copied below into Remote MCP server URL and click Add.
    5. In a chat, click + → Connectors and switch the new connector on.

    Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

    Authorization

    After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

    How to connect MotionSpec — verified web motion (reduced-motion / WCAG) to ChatGPT

    The server address to paste into ChatGPT settings:

    https://api.motionspec.dev/mcp

    1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
    2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
    3. Open Settings → Connectors and click Create.
    4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
    5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
    6. In a new chat open + → Apps/Connectors and enable the connector.

    OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

    Authorization

    On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

    How to connect MotionSpec — verified web motion (reduced-motion / WCAG) to Cursor

    The server address to paste into Cursor settings:

    https://api.motionspec.dev/mcp

    Fastest: click Open in Cursor below and confirm the prompt.

    Manually:

    1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
    2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
    3. Save the file. The server appears in the MCP list; authorize it there if asked.

    Authorization

    If the service needs sign-in, an authorize button appears next to the server in the MCP list.

    Server tool list (5)

    Raw names from tools/list. Only developers need these.

    motion_catalogReturns the catalog of verified motion primitives (names, purpose, parameter schemas, defaults) plus the authoring rules for writing a MotionSpec. Call this FIRST, then write the spec yourself and validate it with motion_validate (motion_compile runs in the CLI or with a key on the hosted endpoint). Free motion check: motionspec.dev/motion-check · keys for the hosted endpoint: motionspec.dev/pricing?src=mcp.
    motion_validateChecks a MotionSpec against the schema, the primitive allow-list, parameter bounds and injection rules. Fail-closed: returns ok=false with precise errors. Returns {ok, errors, warnings, deprecations, catalogVersion}. IMPORTANT: warnings[] carries the WCAG 2.2.2 / reduced-motion findings and can be non-empty while ok=true — a spec that compiles is not automatically accessible. Use to pre-check a spec before compiling.
    motion_compileRequires a Dev Key ($39/mo) or Agency plan ($249/mo) on the hosted endpoint (motionspec.dev/pricing?src=mcp); runs locally for free with 'npx -p motionspec motion compile <spec.json>' (MIT). Validates (fail-closed) and deterministically compiles a MotionSpec into production-ready vanilla-GSAP JavaScript and CSS, with enforced prefers-reduced-motion fallbacks and a performance-budget report. Same spec always yields identical code. Returns {ok, js, css, report} or {ok:false, errors}.
    motion_auditRequires a Dev Key ($39/mo) or Agency plan ($249/mo) on the hosted endpoint (motionspec.dev/pricing?src=mcp). Static motion-a11y checker: fetches a URL's HTML + linked stylesheets and scans the CSS for (1) animation/transition that moves without an effective (cascade-aware) prefers-reduced-motion guard, (2) animated non-transform/opacity properties, (3) infinite animations with no pause path, (4) <marquee>/autoplay >5s. Colour/opacity-only transitions are not motion (WCAG 2.3.3). Same engine and scoring as the free site check at motionspec.dev/motion-check. Returns {ok, score|null, status, findings, groups, summary, badge, disclosures, coverage, markdown}; pages without CSS motion return status 'not-measurable' with score null (runtime motion such as WAAPI/GSAP/WebGL is not audited); loading indicators (spinners, skeletons) are reported as 'review', not as violations. A clean, measurable page earns the badge 'reduced-motion-safe'. Does network I/O (openWorldHint).
    motion_statsRequires a Dev Key ($39/mo) or Agency plan ($249/mo) on the hosted endpoint (motionspec.dev/pricing?src=mcp). Summary of routing/compile telemetry (counts per outcome). Escalation clusters indicate which new primitive the catalog needs next.