How to monetize your API for AI agents (with one line of code)

You built an API. It's good. Developers use it. But there's a new type of customer knocking on your door — and they can't sign up. AI agents are the fastest-growing consumer of APIs right now. They discover endpoints, try to call them — and hit your signup page. Account creation, email verification, credit card form. They can't continue. They leave. You never know they were there. This isn't a future problem. It's happening today. The opportunity you're missing AI agents already spend millions on API calls every month. Coinbase's x402 protocol has settled over 75 million transactions. The agent economy is real. Quick math: 10,000 agents call your API once a day at $0.01 each. That's $100/day — or $36,500/year . From traffic you're currently losing. The solution: HTTP 402 HTTP 402 means "Payment Required." It's been in the HTTP spec since 1997. Nobody used it — until now. Here's how it works: An agent sends a request to your API Your server responds with 402 Payment Required (price, tok