x402

Learn about the x402 protocol

What is x402?

x402.org is an open payment protocol that brings stablecoin payments to plain HTTP.

It revives the HTTP 402 Payment Required status so that servers can charge for APIs and digital content seamlessly.

Clients (human users or AI agents) can pay programmatically to access resources without accounts, API keys, or complex authentication.

Why x402?

Legacy payment rails weren’t built for the web’s speed or for machine-to-machine use.

They are slow, costly, and require sign-ups and keys.

x402 embeds payment into the web’s native request–response flow, enabling instant, global, usage-based payments with minimal integration—ideal for humans and autonomous agents alike.

Benefits

• Simple HTTP integration using status code 402

• Pay-per-request and other usage-based pricing

• Micropayments with stablecoins (e.g., USDC on Solana)

• Agent-native: AI agents can discover and pay automatically

• Zero friction: no accounts, API keys, or session management