x402 embeds HTTP payment directly into the web, enabling AI agents to pay for API calls with USDC on Stellar. Developers can monetize endpoints with 30 lines of code, turning the web into a marketplace of programmable services.
x402 introduces a 402 Payment Required HTTP response that allows AI agents to automatically pay for API calls using USDC stablecoins on Stellar. Instead of managing subscriptions, API keys, and billing dashboards, developers can expose endpoints and charge per request. Stellar's five-second finality, USDC settlement, and sponsored fees via OpenZeppelin relayers enable micropayments at scale. The article argues this approach will evolve beyond paid APIs to real-world services like flights, groceries, and logistics, fundamentally transforming the web from a network of links into a marketplace where software directly participates in the economy.
