Hey HN – I built Nightmarket because I kept running into the same problem building AI agents: every time my agent needed a new capability (weather data, enrichment, web scraping, whatever), I had to go sign up for a service, grab an API key, store it, figure out billing, and wire it all together. Multiply that by 10 services and it's a mess. Agents can't sign up for accounts. They can't enter credit cards. They can't manage API keys. But they can hold a USDC balance and pay per request. Nightmarket is a marketplace where AI agents discover and pay for API services on-chain. No accounts, no API keys, no subscriptions. Your agent pays per call in USDC via x402. How it works:

Browse the marketplace — each service shows pricing, live usage stats, and docs Give your agent the Nightmarket skill (one line in your system prompt, or npx skills add Fallomai/skills --skill nightmarket) Your agent discovers, calls, and pays for services automatically. USDC settles on Base per request.

The whole flow: Agent → discover → call → pay → 200 OK One integration unlocks every service on the marketplace. Your agent doesn't need a separate key for each provider — it just pays and gets data. For sellers: list your API, set a per-call price, and go live immediately. No approval process. Agents start calling as soon as you're listed. You get paid in USDC. Every listing shows live call volume and revenue so buyers can pick providers with proven track records. What makes this different from existing API marketplaces: RapidAPI and friends are built for humans with credit cards. Nightmarket is built for agents with wallets. The x402 protocol (HTTP 402 "Payment Required") means payment is native to the HTTP request itself — no webhooks, no billing dashboards, no invoices. An agent hits an endpoint, gets a 402, pays, retries, gets data. One round trip. We're live at https://nightmarket.ai — you can browse services now and plug the skill into any agent (Claude, GPT, open-source, whatever). Curious to hear from HN:

API providers: would you list your service? What's stopping you from monetizing to agents today? Agent builders: what APIs do you wish your agents could just pay for and use without the signup/key dance? Anyone: poke holes in the model — what breaks when agents are the primary buyer?