numberbroom-mcp

NumberBroom MCP Server

A remote MCP server that lets AI agents verify US phone numbers through the NumberBroom API: carrier-level line type, carrier name, an activity score with a likely-disconnected flag, and known-litigator status. Agents can also hand their user a link to add credit, or to pay for scrubbing a whole list.

Every tool call becomes a call to https://numberbroom.com/api/v1, which owns rate limiting, billing, refunds and abuse protection. See numberbroom.com/developers for the REST API this wraps.

Tools

Tool	Description	Cost
verify_phone_number	Line type, carrier, activity score and a known-litigator flag for one US number. The flag covers numbers tied to TCPA, FDCPA, FCRA and CFPB suits in court filings; it does not say which law, and no database catches every litigator.	$0.20/call from your NumberBroom credit, or on your AWS bill if the account is linked through AWS Marketplace. Unparseable numbers and numbers outside the US are not charged.
get_credit_balance	Remaining pre-paid credit on your NumberBroom account, or that its lookups are billed through AWS Marketplace.	Free.
buy_credits	A Stripe Checkout link that adds credit to the account.	Free to call; the person pays on Stripe.
scrub_list	Sends a whole list (up to 10,000 numbers) for NumberBroom's paid list scrub and returns the price and a Stripe Checkout link.	Free to call; the person pays per list by card.
get_list_status	Status and counts for a list scrub, with one-hour download links once it is done: the cleaned file, the removed rows with their reasons (a Do Not Call Registry match is counted, never listed), the known litigators alone, and the rows of any numbers outside the US, which are not scrubbed or charged.	Free.

Connect a client

The server URL is https://numberbroom.com/mcp. There are two ways to connect:

• Sign in (OAuth). Clients that connect with a sign-in discover the authorization server from the server's 401 challenge. You sign in or create a NumberBroom account, add credit if the account has none, and approve. The client gets a token; the API key behind it stays inside the connection, and you can disconnect it any time in NumberBroom's Settings. Client registration is by Client ID Metadata Document only.

• API key header. Clients that send a header can use a key from numberbroom.com/settings:

  Authorization: Bearer nb_live_YOUR_KEY
  

Step-by-step setup for each client is at numberbroom.com/mcp-server. Opening https://numberbroom.com/mcp in a browser redirects there; MCP clients are unaffected.

Local development

npm install
npm run dev

This starts the server at http://localhost:8787/mcp via wrangler dev. The OAuth flow needs the OAUTH_KV binding (local under wrangler dev) and the MCP_INTERNAL_SECRET secret.

Deploy

npm run deploy

Deploys to Cloudflare Workers as numberbroom-mcp. Requires a Cloudflare account authenticated via wrangler login.

How it is built

• OAuth is @cloudflare/workers-oauth-provider. NumberBroom's own sign-in (numberbroom.com/connect) is the identity step. After you approve, NumberBroom's API gives this Worker a key for your account server to server, and the Worker keeps it only inside the encrypted grant in KV. Tokens and codes are stored as hashes.
• Limits and billing are enforced once, by NumberBroom's API: 5,000 lookups per key per day at most, 500 for calls through this server unless the key has its own limit, the circuit breaker, and refunds for failed lookups.
• An upstream error page or network failure comes back to the agent as a plain tool error, never a thrown exception.
• Each request builds an isolated MCP server instance; no state crosses between callers.

License

MIT