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

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
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.
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.

bash

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.

mcpindex

What it does

What it costs

Tools

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