The latest articles on DEV Community by Mohamed Arafa (@mohamed_arafa_87bd1baa415). https://dev.to/mohamed_arafa_87bd1baa415 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4196198%2F0fad77eb-b737-4582-84b7-e8be2a2a773d.png https://dev.to/mohamed_arafa_87bd1baa415 en Mohamed Arafa Tue, 20 Oct 2026 12:48:53 +0000 https://dev.to/mohamed_arafa_87bd1baa415/selling-apis-to-ai-agents-with-x402-69-endpoints-cloudflare-workers-zero-api-keys-34na https://dev.to/mohamed_arafa_87bd1baa415/selling-apis-to-ai-agents-with-x402-69-endpoints-cloudflare-workers-zero-api-keys-34na <h2> The pitch </h2> <p>An AI agent needs the EUR/EGP rate. It calls <code>GET /v1/fx/EUR</code>. The server answers <code>402 Payment Required</code> with a price ($0.01) and a wallet. The agent signs a USDC transfer on Base, retries with an <code>X-PAYMENT</code> header, gets JSON. No signup, no API key, no invoice. That's x402.</p> <p>I spent two nights building three services on top of it, all on Cloudflare Workers.</p> <h2> What's live </h2> <p><strong>WorldData402</strong> — 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.</p> <p><strong>Inference402</strong> — 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.</p> <p><strong>Briefs402</strong> — 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.</p> <h2> Stack </h2> <ul> <li>Hono + <code>@x402/hono</code> for the paywall</li> <li>PayAI facilitator (no account needed, 1,000 free settlements, then ~$0.002 each)</li> <li>Cloudflare Workers AI for models (10k neurons/day free, then $0.011 per 1k)</li> <li>One <code>catalog.js</code> per service generates routes, <code>/.well-known/x402</code>, <code>/openapi.json</code> and <code>SKILL.md</code> </li> <li>Settlement happens only after a 2xx response, so failed calls are never charged</li> </ul> <h2> Things that bit me </h2> <ul> <li> <code>x402.org/facilitator</code> is testnet-only. For Base mainnet you need CDP (needs KYC) or PayAI/Mogami (no account).</li> <li>x402scan needs <code>/.well-known/x402</code> plus an OpenAPI with an input schema on every paid route, or it won't list the route.</li> <li>Several US government APIs (Treasury, USAspending) refuse Cloudflare Workers egress IPs with TLS failures. GDELT rate-limits the whole Workers IP pool.</li> <li>RapidAPI shows <code>operationId</code> as the endpoint name, not <code>summary</code>.</li> </ul> <h2> Distribution </h2> <ul> <li>x402scan: all three listed</li> <li>Circle Agent Marketplace: submitted</li> <li>RapidAPI (card payments, free tier): <a href="https://rapidapi.com/MohamedArafa/api/worlddata402" rel="noopener noreferrer">https://rapidapi.com/MohamedArafa/api/worlddata402</a> and <a href="https://rapidapi.com/MohamedArafa/api/inference402" rel="noopener noreferrer">https://rapidapi.com/MohamedArafa/api/inference402</a> </li> <li>MCP server for Claude Desktop / Claude Code / Cursor: <code>npx -y worlddata402-mcp</code> — all 69 endpoints as tools, paid from a small wallet via <code>WALLET_PRIVATE_KEY</code> </li> </ul> <h2> Honest status </h2> <p>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.</p> ai webdev cloudflare api