What is x402? — A protocol that revives the HTTP 402 status code with on-chain micropayments, so any API, article, or model call can be billed per use within milliseconds.
A 402 from the server triggers on-chain settlement — no redirects, confirmed in milliseconds.
Every unlock maps to an on-chain transaction receipt: auditable, traceable, tamper-proof.
Integrate at the gateway or middleware layer — a single line of code adds a paywall to any existing service.
Compare the experience of traditional payment versus the x402 protocol in an article-unlock scenario.
Traditional payment paths require redirecting to a checkout, binding a credit card, and waiting for clearing. The latency is measured in seconds or even days — it cannot support high-frequency, per-call micropayments.
We will show how to return a 402 in Express/Next.js middleware, and let the wallet automatically intercept, sign, and retry.
