x402 Protocol
The HTTP 402 payment protocol reimagined for the blockchain era. Native micropayments for every HTTP request.
Protocol Vision
HTTP 402 "Payment Required" was defined in HTTP/1.1 but never implemented. x402 brings this vision to reality using blockchain technology, enabling instant trustless micropayments at internet scale.
Request Flow
Client Request
Client sends HTTP request to an x402-protected API endpoint
402 Response
Server returns HTTP 402 with payment instructions: amount, address, and accepted tokens
Payment Execution
Client creates and signs blockchain transaction to specified payment address
Proof Submission
Client retries request with transaction signature as payment proof in headers
Validation & Response
Server verifies payment on-chain and returns requested resource if valid
Core Advantages
True Micropayments
Charge $0.0001 per request. Traditional payment rails collapse at this scale.
Sub-Second Settlement
Payments finalize on-chain in under a second. No multi-day clearing windows.
Borderless Commerce
Anyone with a wallet can transact. No geographic restrictions or card networks.
Machine Economy Ready
Perfect for AI agents and autonomous systems that need to pay for services.
Multi-Chain Support
Base
L2 Ethereum • Low fees
Solana
High performance • Sub-cent fees
Polygon
EVM compatible • Fast
BSC
Binance chain • Low cost
Sei
Optimized L1 • Speed
Peaq
DePIN network • IoT
Start Building
Ready to integrate x402 payments? Choose your stack and start building in minutes.
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