# Designesy — /docs/mcp Canonical page: https://www.designesy.org/docs/mcp --- ## MCP server Designesy design intelligence over the Model Context Protocol — seventeen tools, one endpoint, one MCP App, no wrapper. The Designesy MCP server runs natively on the same Vercel project as this site. It speaks the 2026-07-28 Streamable HTTP spec — stateless, no sessions, no handshake. Any MCP-compatible client can connect. `https://www.designesy.org/api/mcp` Streamable HTTP · POST · JSON or SSE response · stateless `io.github.LE-VAI/designesy-org` v1.3.1 on `registry.modelcontextprotocol.io` Discoverable by any MCP-compatible client. Search `designesy` on the registry or connect directly. ## Conformance 0 violations axe-core 4.13.0 · wcag22aa · pinned to current npm latest (verified 2026-08-30 via registry check) 90% A /export/dtcg · 9/10 checks pass · 1 WARN (custom types non-standard, namespaced designesy.* per t07) · verified 2026-08-30 93% A 42-check engine · 38 PASS / 0 FAIL / 0 WARN / 1 SKIP / 3 MANUAL ## Tools Seven read-only tools fetch public machine exports from designesy.org. Nine executable tools run live verification — the 42-check score engine, DTCG token validation, Lottie motion validation, drift scoring, AI-readiness scoring, guardrails generation, monitor scoring, design-system comparison, and the composite report. One accessibility framework provides the WCAG 2.2 Playwright + axe-core script template. All tools return JSON. ## Client configuration Copy-paste the config for your client. Most modern clients support Streamable HTTP natively — just point them at the endpoint. For stdio-only clients, use the mcp-remote bridge. ### Claude Code (CLI) ~/.claude.json or ~/.claude/settings.json ``` { "mcpServers": { "designesy": { "type": "http", "url": "https://www.designesy.org/api/mcp" } } } ``` Claude Code (the CLI agent) supports Streamable HTTP natively via type: "http". This is separate from Claude Desktop (below). ### Cursor .cursor/mcp.json (project) or ~/.cursor/mcp.json (global) ``` { "mcpServers": { "designesy": { "url": "https://www.designesy.org/api/mcp" } } } ``` Cursor supports Streamable HTTP directly — just provide url. It auto-detects HTTP vs SSE. No type field needed. ### ZCode .zcode MCP config (User or Workspace scope) ``` { "mcpServers": { "designesy": { "url": "https://www.designesy.org/api/mcp" } } } ``` ZCode supports HTTP, SSE, and stdio. Add via Settings → MCP Servers (type: HTTP), or paste this JSON in full config mode. ### VS Code + Copilot .vscode/mcp.json ``` { "servers": { "designesy": { "type": "http", "url": "https://www.designesy.org/api/mcp" } } } ``` VS Code with GitHub Copilot supports HTTP MCP servers. Note: key is "servers", not "mcpServers". VS Code tries HTTP Stream first, falls back to SSE. ### Claude Desktop (stdio-only — needs mcp-remote bridge) ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) %APPDATA%\Claude\claude_desktop_config.json (Windows) ``` { "mcpServers": { "designesy": { "command": "npx", "args": ["mcp-remote@latest", "https://www.designesy.org/api/mcp"] } } } ``` Claude Desktop's JSON config is stdio-only — a url field silently deletes the entire mcpServers block (bug #37286). Use the mcp-remote npm package as a stdio bridge. Alternatively, add the server via Settings → Connectors → Add custom connector (no JSON editing, supports public HTTPS directly). ## How it works Vercel Node.js serverless · mcp-handler 2.x (Vercel's official MCP adapter) · @modelcontextprotocol/server (SDK v2) · Zod 4 · stateless 2026-07-28 spec native · 300-second max duration (Pro Plan) 5-minute in-memory cache on read-only tools. Vercel Fluid Compute reuses warm instances, so cache hits are common. The executable tool (designesy_score) is never cached — every score request hits the live engine. The server is native TypeScript. It runs in the same Vercel runtime as this site — no child processes, no mcp-proxy bridge, no external dependencies beyond the MCP SDK. The seven read-only tools fetch the same public machine exports that any HTTP client can fetch directly. The MCP server adds structured tool schemas, Zod validation, and a single authenticated endpoint — useful for agents that prefer the MCP protocol over raw HTTP. ## Quick test Verify the endpoint is live with a single curl: ``` curl -X POST https://www.designesy.org/api/mcp \ -H "Content-Type: application/json" \ -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' ``` The response is a JSON-RPC 2.0 message listing all seventeen tools with their schemas. ## Related - [Docs · orientation — Mission, principles, architecture, public voice](https://www.designesy.org/docs) - [Open design intelligence — Human index and machine feed of portable packages](https://www.designesy.org/open) - [open.json — Machine catalog — the same data the MCP server serves](https://www.designesy.org/open.json) - [Design system contract — v0.4.0 — the contract behind designesy_contract](https://www.designesy.org/contracts/design-system)