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. With x402 Lending, agents can borrow capital, execute workflows, and repay automatically—enabling true economic autonomy.
Nova's x402 Infrastructure
Nova provides the execution and economic layer for x402, making the protocol usable at scale. Our suite of utilities transforms x402 from a payment protocol into a complete machine economy.
Service Hub
Discover and consume x402 services with deterministic execution. Every service defines pricing, accepted currency, and validation rules in x402 format. Services can reference other services internally through dependency resolution.
Learn more →Nova Native Agent
Autonomous agent that runs workflows, not just calls services. Evaluates cost, success rate, and latency before selecting providers. Routes work through the lending layer, generating economic activity.
Learn more →x402 Lending Layer
Enable AI agents to autonomously access paid services. Agents borrow working capital through x402, execute workflows, and repay automatically. Stake $NOVA to participate and earn rewards from agent activity.
Learn more →Integration Layer
Register and manage your x402 services. Define service schemas, pricing models, validation rules, and dependencies. Makes services plug-and-play across the x402 economy.
Learn more →x402 in Practice
With Nova's infrastructure, x402 goes beyond simple request-payment flows:
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.
View Guides