mcpindex.ai

The in-path trust gate for agent tool calls.

MCP tool contracts can change remotely with no version bump. mcpindex pins each contract and HOLDs the call when it drifts — before your agent acts. Deterministic contract-diff on your host. Zero credential custody. Not a safety oracle.

Live site · Install gate · npx mcp-server-mcpindex · pip install mcpindex-gate · Remote MCP · Docs · Trust · Methodology

What you get

1. In-path drift gate — one command wires Claude Desktop / Claude Code / Cursor / Gemini CLI / Cline / Zed so each MCP server launches behind the gate. Local, fail-closed, default build egresses nothing.
   curl -fsSL https://mcpindex.ai/install.sh | sh (inspect first with | less) · PyPI: mcpindex-gate
2. Advisory directory — search, recommend, preflight (/api/v1/preflight), and trust lookups over HTTP or as a drop-in MCP server (mcp-server-mcpindex). Screen verdicts are REVIEW / UNVERIFIED at v1; ALLOW / DENY are reserved in the contract.
3. Agent-readable surfaces — /llms.txt, /.well-known/mcp-index.json, JSON-LD, and a per-server page for every indexed server (live count at mcpindex.ai/stats).

The gate is the wedge. The directory is the corpus the gate can query — also free.

Develop

Canonical local path: /Volumes/GB990Pro/GBCode/mcpindex-web.
If you also have mcpindex-STALE-DO-NOT-DEPLOY/ (or an old mcpindex/ clone), ignore it — it is a blocked backup, not the live site.

npm install
node scripts/sync-registry.mjs     # pull the registry: snapshot + removals + slug map
npm run dev                         # http://localhost:3000

Snapshot lives at data/snapshot.json (committed). Refresh anytime with the script.

Stack

• Next.js 16 (App Router) on Vercel
• Tailwind v4
• Local snapshot of registry.modelcontextprotocol.io/v0/servers, refreshed daily via Vercel cron
• Quality Score: lib/quality.ts (open methodology - PRs welcome)
• Search: lib/search.ts (keyword now; embeddings v2 when OPENAI_API_KEY is wired)

Project layout

mcpindex/
├── app/                    # Next.js routes
│   ├── api/v1/             # Versioned public API
│   ├── api/cron/           # Vercel-cron-driven endpoints
│   ├── server/[slug]/      # per-server pages (top-N SSG + ISR)
│   ├── best/[category]/    # curated category pages
│   └── ...                 # docs, trust, methodology, ledger, …
├── components/             # Header, Footer, DriftGateDemo, LiveTicker, …
├── lib/                    # registry, quality, search, verdicts, installs, …
├── scripts/                # sync-registry.mjs, build-slugmap.ts, honesty guard
├── data/                   # snapshot.json (committed) + snapshots/ (cron-written)
├── mcp-server-mcpindex/    # the npm-distributed MCP directory client
└── …

License

• Web app code: source-available, all-rights-reserved (prevents direct fork-and-deploy by competitors).
• mcp-server-mcpindex (the npm package): MIT.
• MCP Quality Score methodology: open and PR-friendly.

Affiliation

Unofficial. Not affiliated with Anthropic. The Model Context Protocol is open under MIT and trademarks remain with their owners. Server data comes from the official MCP registry.