x402

x402 is the open payment protocol that activates the dormant HTTP 402 status code, enabling instant, machine-native settlement for digital resources.

This is the internet’s native payment layer: x402 revives the HTTP 402 “Payment Required” status code, transforming the standard request-response cycle into a direct, pay-per-use transaction. The protocol allows a server to respond with a 402 status, detailing payment requirements (e.g., USDC on Base), which an AI agent or client wallet fulfills instantly. This system eliminates traditional friction like accounts and subscriptions, providing permissionless, near-zero-fee settlement, often in under two seconds. It is critical infrastructure for the emerging agentic economy, allowing autonomous AI agents to discover and pay for API access and data without human intervention.

https://www.x402.org/