@gravity-ai/index-mcp

An MCP server that lets AI coding agents discover developer services and get install instructions from the Gravity Index.

Zero dependencies, zero build step — a single Node.js file that speaks JSON-RPC 2.0 over stdio.

npx -y @gravity-ai/index-mcp

What it does

The Gravity Index catalogs ~490 installable developer services (databases, auth, payments, hosting, email, monitoring, AI/ML, etc.) with install summaries and env vars. This MCP server exposes five tools to any MCP-compatible agent:

| Tool | What it does | |---|---| | gravity_index_search | LLM-reasoned recommendation for a stated need, with install steps + setup link | | gravity_index_browse | List services by category or keyword | | gravity_index_get_service | Full detail for a single service by slug | | gravity_index_list_categories | Enumerate all categories with counts | | gravity_index_report_integration | Record a conversion when the agent finishes the install |

Installing in Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "gravity-index": {
      "command": "npx",
      "args": ["-y", "@gravity-ai/index-mcp"]
    }
  }
}

Restart Claude Desktop. You should see the gravity_index_* tools listed.

Installing in Cursor

Settings → MCP → Add server:

{
  "mcpServers": {
    "gravity-index": {
      "command": "npx",
      "args": ["-y", "@gravity-ai/index-mcp"]
    }
  }
}

Installing in Cline / Continue / Zed / Other MCP clients

Any MCP client that supports the stdio transport works — point it at the command npx -y @gravity-ai/index-mcp. No other runtime deps (Python, Docker, etc.) are required.

Environment variables

| Var | Default | Notes | |---|---|---| | GRAVITY_INDEX_URL | https://index.trygravity.ai | Override for self-hosted or staging | | GRAVITY_PUBLISHER_KEY | (unset) | Your Gravity publisher API key — if set, referral conversions attribute to your account (CPA revenue share) |

If you're a platform publisher (building a tool that embeds this MCP for your users), set GRAVITY_PUBLISHER_KEY so every install attributes to you.

Example conversation

you:  I need a serverless SQL database with branching
agent uses gravity_index_search → returns Neon with:
  - npm install @neondatabase/serverless
  - lib/db.ts stub
  - DATABASE_URL env var
  - https://index.trygravity.ai/go/abc123  ← setup link
  - search_id: s_0f9...
agent: Here's the setup. Open the link above, paste your DATABASE_URL
       back, and I'll wire it up.
you:  [pastes URL] done
agent uses gravity_index_report_integration(search_id=s_0f9..., integrated_slug=neon)
       → records the conversion

See also

• Gravity Index REST API: https://index.trygravity.ai
• Docs: https://docs.trygravity.ai/gravity-index/introduction
• Python MCP (identical tools, requires python3): index/mcp/gravity_index_mcp.py in the Gravity monorepo