Selling APIs to AI agents with x402: 69 endpoints, Cloudflare Workers, zero API keys
The pitch An AI agent needs the EUR/EGP rate. It calls GET /v1/fx/EUR . The server answers 402 Payment Required with a price ($0.01) and a wallet. The agent signs a USDC transfer on Base, retries with an X-PAYMENT header, gets JSON. No signup, no API key, no invoice. That's x402. I spent two nights
An AI agent needs the EUR/EGP rate. It calls GET /v1/fx/EUR. The server answers 402 Payment Required with a price ($0.01) and a wallet. The agent signs a USDC transfer on Base, retries with an X-PAYMENT header, gets JSON. No signup, no API key, no invoice. That's x402.
I spent two nights building three services on top of it, all on Cloudflare Workers.
WorldData402 — 39 data endpoints: FX for 160+ currencies, historical rates, SEC company filings, EU public tenders, World Bank indicators, EU VAT validation, public holidays, geocoding, weather, air quality, earthquakes, Wikipedia, arXiv, Crossref, RDAP, DNS, npm/PyPI, barcodes. $0.01–$0.05 per call.
Inference402 — 15 endpoints on Cloudflare Workers AI: chat (small/large), structured JSON output, summarize, translate (plus an Arabic-tuned route that handles Egyptian dialect), extract, classify, sentiment, keywords, rewrite, embeddings, moderation, image description, Whisper transcription. $0.002–$0.02.
Briefs402 — 10 composite reports (company, country, market, tenders, domain due-diligence, location, research literature, product, package risk, long-document translation). It calls the other two internally and sells the finished brief for $0.10–$0.50.
48 hours live, ~2k requests (all mine), 0 paid calls. Supply is done. If you've sold to agents and found what drives discovery, I'd like to hear it.