designesy-mcp

One-click install:

A read-only stdio MCP server exposing designesy.org's design-intelligence infrastructure as native agent tools.

Zero external dependencies. Pure Python stdlib. Implements the Model Context Protocol JSON-RPC 2.0 over stdio.

Quick start (one command)

uvx designesy-mcp

That's it. uvx fetches the package from PyPI, creates an ephemeral environment, and launches the stdio MCP server. No virtualenv, no pip install, no git clone. The server is ready to speak JSON-RPC 2.0 on stdin/stdout immediately.

Don't have uv? Install it once: curl -LsSf https://astral.sh/uv/install.sh | sh (macOS/Linux) or powershell -c "irm https://astral.sh/uv/install.ps1 | iex" (Windows). Or use pipx run designesy-mcp as an equivalent one-liner.

MCP client config

uvx (recommended — no install step)

{
  "mcpServers": {
    "designesy": {
      "command": "uvx",
      "args": ["designesy-mcp"]
    }
  }
}

pip install (traditional)

pip install designesy-mcp

{
  "mcpServers": {
    "designesy": {
      "command": "designesy-mcp"
    }
  }
}

python -m (module form)

{
  "mcpServers": {
    "designesy": {
      "command": "python",
      "args": ["-m", "designesy_mcp_server"]
    }
  }
}

No arguments needed. The server speaks JSON-RPC 2.0 over stdin/stdout.

Tools (17)

The server exposes 17 tools, all fetched live from https://www.designesy.org/:

Read-only discovery

Executable verification

Executable engines (new in v1.10.0)

Resources (7)

The server also exposes 7 MCP resources (read-only URIs):

The 40-check verification engine

designesy_score runs 40 deterministic checks across 13 weighted categories:

No LLM. No roast. The same engine scores designesy.org itself — in public, at 95.3% A.

Standards positioning

DTCG 2025.10 — the spec went stable

The W3C Design Tokens Community Group published the spec's first stable version on Oct 28, 2025 — the Final Community Group Report, classified as a Candidate Recommendation and considered stable. 24+ organizations back it (Adobe, Google, Meta, Figma, Amazon, Microsoft, Shopify, Sketch, Framer). 84% of teams now use design tokens (2026, up from 56% YoY).

designesy_tokens_score validates against this stable spec. Every team adopting DTCG 2025.10 needs a validator — designesy is it.

Motion tokens — the spec's blind spot

The DTCG 2025.10 spec leaves motion tokens as a second-class citizen — there is no standard for motion token structure, reduced-motion markers, or animation accessibility. The 2026 State of Design Systems field report confirms this is the remaining friction point.

designesy_motion_score fills this gap. It validates Lottie files against the Lottie spec v1.0.1 AND the Designesy §16 Ten Non-Negotiable Motion Standards — the only validator that checks both structural well-formedness and accessibility (reduced-motion markers, no deprecated versions). It is the verification layer for the spec's known blind spot.

Contract vs. opinion

No competitor does contract-based deterministic scoring. Lighthouse is weighted heuristics. axe-core is rule violations. securityheaders.com is a single dimension. Designesy's 40-check contract-bound 0-100 score across 7 dimensions (tokens, motion, accessibility, cadence, takt, typography, copywriting) has no direct analog.

Caching

All responses are cached with a 5-minute TTL. The server only fetches public, machine-readable exports from designesy.org via HTTPS. It does not read local files, credentials, or source roots.

Safety

Read-only. This server never writes anywhere. It does not execute code, mutate files, or access credentials.

Provenance

All data is fetched live from:

• https://www.designesy.org/open.json
• https://www.designesy.org/contracts/design-system.json
• https://www.designesy.org/kits/design-review.json
• https://www.designesy.org/contracts/skill
• https://www.designesy.org/.well-known/agent.json
• https://www.designesy.org/llms.txt
• https://www.designesy.org/llms-full.txt

License

MIT

Links

• Homepage
• Agent Install — one-command uvx designesy-mcp
• Repository
• MCP Registry entry
• Changelog
• Design-system contract
• Leaderboard — 30-site public cohort, A–F histogram, weekly re-score
• Score badge — embeddable SVG badge for A/B-graded sites
• Live score API — JSON, no key, no login
• Methodology