Rhumb MCP Server

Agent-native tool intelligence for the Model Context Protocol.

Discover, compare, route, and execute across 600+ scored API services. Every tool rated for AI agent use with the AN Score.

• Website: https://rhumb.dev
• Docs: https://rhumb.dev/blog/getting-started-mcp
• Pricing: https://rhumb.dev/pricing
• Repo: https://github.com/supertrained/rhumb

Zero-config quickstart

No API key needed for discovery. Install and start finding tools immediately:

npx rhumb-mcp@latest

Or add to Claude Desktop / Cursor / any MCP client:

{
  "mcpServers": {
    "rhumb": {
      "command": "npx",
      "args": ["-y", "rhumb-mcp@latest"]
    }
  }
}

That's it. Ask your agent:

• "Find me the best email API for agents"
• "What's the AN Score for Stripe?"
• "Compare Resend vs SendGrid vs Postmark"
• "What are Twilio's known failure modes?"

All of these work without an account or API key.

What works without auth (6 tools)

| Tool | What it does | |------|-------------| | find_services | Search 600+ services by what you need | | get_score | Full AN Score breakdown for any service | | get_alternatives | Find alternatives ranked by score | | get_failure_modes | Known failure patterns + workarounds | | discover_capabilities | Browse capabilities by domain (email.send, payment.charge) | | resolve_capability | Get ranked providers with health, cost, and routing data |

What requires auth (10 tools)

For execution, billing, and credential management, add your API key:

{
  "mcpServers": {
    "rhumb": {
      "command": "npx",
      "args": ["-y", "rhumb-mcp@latest"],
      "env": {
        "RHUMB_API_KEY": "rk_your_key_here"
      }
    }
  }
}

Get a key at https://rhumb.dev/auth/login (GitHub or Google OAuth, 30 seconds).

| Tool | What it does | |------|-------------| | execute_capability | Call a capability through Rhumb Resolve | | estimate_capability | Get cost before executing (no charge) | | check_credentials | See what you can call right now | | credential_ceremony | Step-by-step guide to get provider credentials | | budget / spend | Set and track spending limits | | check_balance / get_ledger | View credits and transaction history | | get_payment_url | Get Stripe top-up link | | routing | Choose strategy: cheapest, fastest, highest quality |

Alternative: x402 micropayments. No account needed — pay per call with USDC on Base. Pass x_payment instead of an API key.

Common workflows

1) Discover tools (no auth needed)

"I need an email provider for agents."

• find_services → search the landscape
• get_score → inspect a specific provider
• get_failure_modes → see where it breaks in practice

2) Route a capability (no auth needed)

"I need email.send. What should I use?"

• discover_capabilities → find the capability ID
• resolve_capability → get ranked providers with health data
• estimate_capability → preview cost (requires auth)

3) Execute (auth required)

"Send the email with the cheapest provider above my quality floor."

• execute_capability → actually perform the action
• budget / spend / check_balance → control and audit usage

16 MCP tools

• find_services — search services by need
• get_score — full AN Score breakdown
• get_alternatives — ranked alternatives
• get_failure_modes — failure patterns + workarounds
• discover_capabilities — browse by domain
• resolve_capability — ranked providers with routing data
• execute_capability — call through Rhumb Resolve
• estimate_capability — cost preview (no charge)
• credential_ceremony — provider credential guides
• check_credentials — what modes are available
• budget — set spending limits
• spend — track spending
• routing — choose routing strategy
• check_balance — view credits
• get_payment_url — Stripe top-up link
• get_ledger — transaction history

Local development

cd packages/mcp
npm ci
npm run dev

Test and build

npm test          # 78 tests
npm run type-check
npm run build

Related

• API: https://api.rhumb.dev/v1
• npm: https://www.npmjs.com/package/rhumb-mcp
• MCP Registry: https://registry.modelcontextprotocol.io (search "rhumb")
• GitHub: https://github.com/supertrained/rhumb

License

MIT