Smart Link

Pay-per-call API that tells AI agents whether a domain is a real business. Built MCP-first. Two payment rails: x402 (autonomous, zero signup) + prepaid credits (50 free checks, no credit card).

🚀 Live: https://is-real-biz.is-real-biz.workers.dev — try it now:

curl -X POST https://is-real-biz.is-real-biz.workers.dev/billing/signup \
  -H 'content-type: application/json' -d '{"email":"[email protected]"}'
# returns: { api_key: "irb_live_...", credits_cents: 250 } — 50 free checks

GET /check?domain=stripe.com   →   { verdict: "real", score: 94, signals: { ... } }

Use cases: KYB / vendor screening, lead qualification, fraud checks, due diligence — anywhere an agent needs to know "is this domain a legit business or a parked/scam/fake site?"

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Why agents will find this

Discovery surfaces (over-served on purpose — every agent looks somewhere different):

Surface	Path	Spec
MCP descriptor	/.well-known/mcp.json	modelcontextprotocol.io
MCP HTTP endpoint	/mcp	streamable HTTP
OpenAPI 3.1	/openapi.json	OpenAPI
llms.txt	/llms.txt	llmstxt.org
ai.txt	/ai.txt	early crawler convention
ChatGPT plugin	/.well-known/ai-plugin.json	legacy
A2A agent card	/.well-known/agent.json	A2A v1
agents.json	/.well-known/agents.json	Wildcard spec
Pricing manifest	/pricing.json	this server
robots/sitemap	/robots.txt, /sitemap.xml	SEO

Plus the tool descriptions in src/tool-descriptions.ts are written for embedding-based tool selection — the way Claude/ChatGPT/Cursor actually pick which tool to call. Lots of natural-language examples, use-case tags, and example queries.

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Why agents can pay it

• x402 (spec) — the HTTP 402 payment protocol pushed by Coinbase + Cloudflare. Agents send an X-PAYMENT header, the server verifies + settles via a facilitator in ~2 seconds. Zero signup. No accounts. Sub-cent calls work. Default network is Base Sepolia testnet (free) — flip X402_NETWORK = "base_mainnet" in wrangler.toml to take real payments.
• Prepaid credits — POST /billing/signup with an email returns an API key with 50 free checks. Need more? Redeem an operator-issued promo code at /billing/promo. No credit card, no Stripe, no card-on-file.

Both paths share the same /check endpoint, so any agent that speaks either rail just works.

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Zero-cost deploy (≈ 5 minutes)

You only need:

1. A free Cloudflare account (workers.dev subdomain is free forever) — sign up
2. A free Google AI Studio key for Gemini 1.5 Flash (no credit card) — get key

Then:

git clone <this repo> is-real-biz && cd is-real-biz
npm run setup      # runs deploy.sh — creates D1, KV, applies schema, sets secrets, deploys

The script is interactive: it logs you into Cloudflare, provisions D1 + KV, patches wrangler.toml with the IDs, asks for your Gemini key, and deploys. You'll have a live URL like https://is-real-biz.<your-subdomain>.workers.dev.

Manual deploy

npm install
npx wrangler login
npx wrangler d1 create is-real-biz-db          # paste id into wrangler.toml
npx wrangler kv namespace create CACHE         # paste id into wrangler.toml
npx wrangler d1 execute is-real-biz-db --file=./schema.sql --remote
npx wrangler secret put GEMINI_API_KEY
npx wrangler deploy

Optional secrets

npx wrangler secret put ADMIN_TOKEN     # to mint promo codes via POST /admin/promo
npx wrangler secret put X402_PAY_TO     # your 0x address to enable x402 payments

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Try it

# 1. Get a free key (50 checks included)
curl -X POST https://YOUR-WORKER-URL/billing/signup \
  -H 'content-type: application/json' \
  -d '{"email":"[email protected]"}'

# 2. Check a domain
curl 'https://YOUR-WORKER-URL/check?domain=stripe.com' \
  -H 'authorization: Bearer irb_live_...'

# 3. Batch
curl -X POST https://YOUR-WORKER-URL/check/batch \
  -H 'authorization: Bearer irb_live_...' \
  -H 'content-type: application/json' \
  -d '{"domains":["stripe.com","openai.com","sketchy.xyz"]}'

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Use it from Claude / Cursor / Windsurf (MCP)

{
  "mcpServers": {
    "is-real-biz": {
      "url": "https://YOUR-WORKER-URL/mcp",
      "headers": { "Authorization": "Bearer irb_live_..." }
    }
  }
}

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Issuing promo codes (operator)

# Mint a 100-credit ($1) code, single use
curl -X POST https://YOUR-WORKER-URL/admin/promo \
  -H "X-Admin-Token: $ADMIN_TOKEN" \
  -H 'content-type: application/json' \
  -d '{"amount_cents":100,"max_uses":1,"note":"HN launch"}'

# Mint a multi-use launch code
curl -X POST https://YOUR-WORKER-URL/admin/promo \
  -H "X-Admin-Token: $ADMIN_TOKEN" \
  -H 'content-type: application/json' \
  -d '{"code":"LAUNCH50","amount_cents":250,"max_uses":500}'

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How the verdict is computed

Signal	Source	Cost
Domain age + registrar	RDAP via rdap.org	free
SSL validity	Certificate Transparency (crt.sh)	free
Homepage classification	Gemini 1.5 Flash	free (1500/day)
Contact info presence	regex over homepage + /contact	free
Social-media footprint	regex over homepage	free

Weighted combination → score 0-100 → verdict {real, likely_real, uncertain, likely_fake, fake}. Cached for 24h in KV.

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Submit to MCP registries (after deploy)

• registry.modelcontextprotocol.io — official, post-deploy submit form
• smithery.ai — paste the smithery.yaml
• glama.ai/mcp/servers — submit form
• mcp.so — open PR
• mcpservers.org — open PR
• awesome-mcp-servers — open PR
• The x402 Bazaar auto-indexes you after the first paid call — no submission needed.

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License

MIT.