MotionSpec — verified web motion (reduced-motion / WCAG)
Deterministic motion compiler + validator: reports WCAG 2.2.2 pause-path candidates, fail-closed.
Should I use this
Quality & Safety
Based on automated analysis of tool definitions and protocol compliance.
Context Cost
This is the approximate number of tokens consumed each time the server's tools are loaded into a model's context. Higher counts reduce the attention available for other tasks.
Install
One-Click Install
Add this to your `claude_desktop_config.json` file:
{
"mcpServers": {
"motionspec": {
"command": "npx",
"args": [
"motionspec"
]
}
}
}Runnable packages
1.2.7stdioRemote endpoints
https://api.motionspec.dev/mcpstreamable-httpWhat it can do
Tool inventory
Tools (5)
🟢motion_catalog
Returns 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.
Input Schema
{
"type": "object",
"properties": {},
"$schema": "http://json-schema.org/draft-07/schema#"
}🟢motion_validate(spec)
Checks a MotionSpec against the schema, the primitive allow-list, parameter bounds and injection rules. Fail-closed: returns ok=false with precise errors. Returns {ok, errors, warnings, deprecations, catalogVersion}. IMPORTANT: warnings[] carries the WCAG 2.2.2 / reduced-motion findings and can be non-empty while ok=true — a spec that compiles is not automatically accessible. Use to pre-check a spec before compiling.
Input Schema
{
"type": "object",
"properties": {
"spec": {
"type": "object",
"propertyNames": {
"type": "string"
},
"additionalProperties": {},
"description": "The MotionSpec JSON object"
}
},
"required": [
"spec"
],
"$schema": "http://json-schema.org/draft-07/schema#"
}🟢motion_compile(spec, specName)
Requires a Dev Key ($39/mo) or Agency plan ($249/mo) on the hosted endpoint (motionspec.dev/pricing?src=mcp); runs locally for free with 'npx -p motionspec motion compile <spec.json>' (MIT). Validates (fail-closed) and deterministically compiles a MotionSpec into production-ready vanilla-GSAP JavaScript and CSS, with enforced prefers-reduced-motion fallbacks and a performance-budget report. Same spec always yields identical code. Returns {ok, js, css, report} or {ok:false, errors}.
Input Schema
{
"type": "object",
"properties": {
"spec": {
"type": "object",
"propertyNames": {
"type": "string"
},
"additionalProperties": {},
"description": "The MotionSpec JSON object"
},
"specName": {
"description": "Optional name used in the artifact header",
"type": "string",
"pattern": "^[A-Za-z0-9_-]{1,64}$"
}
},
"$schema": "http://json-schema.org/draft-07/schema#"
}🟢motion_audit(url)
Requires a Dev Key ($39/mo) or Agency plan ($249/mo) on the hosted endpoint (motionspec.dev/pricing?src=mcp). Static motion-a11y checker: fetches a URL's HTML + linked stylesheets and scans the CSS for (1) animation/transition that moves without an effective (cascade-aware) prefers-reduced-motion guard, (2) animated non-transform/opacity properties, (3) infinite animations with no pause path, (4) <marquee>/autoplay >5s. Colour/opacity-only transitions are not motion (WCAG 2.3.3). Same engine and scoring as the free site check at motionspec.dev/motion-check. Returns {ok, score|null, status, findings, groups, summary, badge, disclosures, coverage, markdown}; pages without CSS motion return status 'not-measurable' with score null (runtime motion such as WAAPI/GSAP/WebGL is not audited); loading indicators (spinners, skeletons) are reported as 'review', not as violations. A clean, measurable page earns the badge 'reduced-motion-safe'. Does network I/O (openWorldHint).
Input Schema
{
"type": "object",
"properties": {
"url": {
"type": "string",
"description": "The page URL to audit (http/https)."
}
},
"$schema": "http://json-schema.org/draft-07/schema#"
}🟢motion_stats
Requires a Dev Key ($39/mo) or Agency plan ($249/mo) on the hosted endpoint (motionspec.dev/pricing?src=mcp). Summary of routing/compile telemetry (counts per outcome). Escalation clusters indicate which new primitive the catalog needs next.
Input Schema
{
"type": "object",
"properties": {},
"$schema": "http://json-schema.org/draft-07/schema#"
}Community
Evidence