I built 8 APIs that AI agents pay for automatically

The setup
Solo founder. Wisconsin LLC. No employees, no funding. I wanted to build a competitive intelligence product for small business owners — pay $100, get a branded report in your inbox analyzing your competitors' keywords, messaging, and pricing.
I built the whole pipeline: Stripe payments, Make.com automation, Claude API for research and writing, Resend for email delivery, Vercel for hosting. Styled reports, professional emails, the works.
Zero customers.
The pivot
Instead of spending months marketing to humans who need convincing, I pointed the same infrastructure at AI agents who are already looking to buy intelligence.
Same data sources. Same scoring logic. Different buyer, different delivery format, different economics.
Old model: Human pays $100 via Stripe → waits 15 min → gets PDF via email → maybe buys again next month
New model: Agent pays $0.12 via x402 → gets JSON in seconds → calls again automatically
What I built
8 intelligence API endpoints, each bundling 7-9 premium data sources into a single scored response:

Domain Shield ($0.12) — VirusTotal malware scan + SPF/DKIM/DMARC/SSL/MX/DNSSEC
Company X-Ray ($0.15) — People Data Labs + Hunter.io for firmographics and contacts
Threat Pulse ($0.10) — VirusTotal + AbuseIPDB for IP/domain threat intel
Compliance Check ($0.15) — Qualys SSL Labs grading + security header audit
Prospect IQ ($0.12) — Sales intelligence with verified email contacts
Sports Edge ($0.12) — ESPN + odds from 15+ bookmakers + AI analysis
Property Intel ($0.10) — US Census demographics + weather + amenities
Health Signal ($0.10) — NIH RxNorm drug interactions + FDA data

Payment happens via x402 — the HTTP 402 protocol. Agent hits the endpoint, gets a "pay first" response, sends USDC on Base, retries with proof of payment, gets data. No accounts, no API keys, no subscriptions.
The stack
Everything runs on free or near-free infrastructure:

Vercel (free tier) — hosts the gateway + all endpoints
Express + @x402/express SDK — single gateway file routes all 8 endpoints
CDP facilitator — Coinbase handles payment verification and settlement
Premium APIs — VirusTotal, People Data Labs, Hunter.io, AbuseIPDB, Qualys SSL Labs, NIH RxNorm, The Odds API
Claude Haiku — AI synthesis for sports analysis

Total monthly cost: ~$0. The premium API calls only happen when someone pays, so costs scale with revenue.
Distribution — the hard part
"Build it and they will come" does not work in the x402 ecosystem. Bazaar discovery (the official x402 indexing layer) has known bugs — multiple builders can't get indexed despite correct setup.
What actually worked:

Decixa — Third-party discovery layer. All 8 endpoints indexed within 24 hours. They're becoming the de facto x402 directory.
awesome-mcp-servers — PR merged into the 84k-star repo. Permanent listing.
npm packages — alderpost-mcp (MCP server for Claude/Cursor users) and x402-buyer-mcp (universal buyer agent with Decixa-powered discovery)
x402scan — All 8 endpoints registered with full schemas

What didn't work: Reddit (new account spam-filtered), Bazaar auto-indexing (still broken for most builders), Smithery (requires HTTP transport).
The honest numbers

Revenue: $0.12 (one test transaction)
npm downloads: 500+
Real paying agent traffic: near zero
x402 ecosystem daily volume: ~$14K across all sellers, roughly half is test traffic

What I learned

1. The x402 ecosystem is real but early. 5,500+ verified endpoints exist. Multiple protocols are competing (x402, MPP, ACP, AP2). Nobody has won yet.
2. Distribution matters more than product. My endpoints work perfectly. The problem is getting agents to find them. Every hour spent on Decixa integration, awesome-mcp-servers PRs, and Discord relationships has been more valuable than any code I wrote.
3. The SMB report product isn't dead. The same intelligence engine powers both products. Once agents start generating traffic, the "our engine serves AI agents and now you can get that same intelligence as a personalized report" pitch gets a lot stronger.
4. Solo building is possible but slow. Every PR, every npm publish, every Discord conversation is one person. The tradeoff is zero overhead — my break-even is literally $0/month. What's next

Stripe MPP support (accept fiat payments from agents without crypto wallets)
Milwaukee outreach for the SMB report product (10 prospects ready)
Reddit karma building so I can actually post without getting filtered
Waiting for the x402 ecosystem to grow — when it does, the endpoints are already there

If you're building in the agent economy, happy to share what I've learned. The infrastructure is surprisingly accessible — the hard part is distribution, not code.

Links:

alderpost.co
npm: alderpost-mcp / x402-buyer-mcp
GitHub