Welcome to
x402
The Internet-Native Payment Protocol
Built on HTTP. Chain-agnostic. Zero fees.
2-second settlement for the AI agent economy.
How x402 Works
Four simple steps to enable internet-native payments
Client Requests Resource
An AI agent or application requests a paid API endpoint
GET /api/premium-dataServer Returns 402
Server responds with HTTP 402 Payment Required and payment details
402 Payment Required
{address, amount, chain}Client Sends Payment
Client automatically pays via blockchain (2 seconds)
Pay 0.1 USDC
to 0x742d...Access Granted
Client retries request with payment proof, receives resource
200 OK
{data: "premium content"}Simple. Standard. Universal.
x402 leverages the HTTP 402 status code—reserved for payments since 1997 but never implemented—to create a standardized payment protocol that works with any HTTP stack, any blockchain, and any token.
Why x402
The first truly internet-native payment protocol
Zero Fees
No transaction fees for merchants or customers. Keep 100% of your revenue.
2-Second Settlement
Blockchain-powered instant settlement. Money in your wallet, not T+2.
Chain Agnostic
Works with any blockchain. Ethereum, Solana, Base, Polygon, and more.
HTTP Native
Built on standard HTTP. Works with any server stack, any language.
Open Standard
No vendor lock-in. Community-driven. Anyone can implement or extend.
Zero Friction
No registration, no OAuth, no personal info required from customers.
AI Agent Ready
Purpose-built for autonomous AI agents. Programmatic, instant payments.
Self-Custodial
Payments go directly to your wallet. No intermediary, no custody risk.
Micropayments
Enable pay-per-use models. No forced subscriptions or ads required.
Built for the Future of the Internet
x402 is designed for a world where AI agents are economic actors, where micropayments replace subscriptions, and where financial transactions happen at internet speed.
x402 for Everyone
From autonomous AI agents to indie creators, x402 enables new economic models
For AI Agents
Autonomous Economic Actors
API Access
AI agents pay for premium API calls automatically without human intervention.
Data Purchases
Real-time data acquisition with instant micropayments.
Cloud Services
Pay-per-use cloud compute, storage, and bandwidth.
Real-World Examples
AI Research Labs
AI agents access premium research papers and datasets on-demand, paying per download
Cloud Storage
Users pay $0.001 per GB per hour without accounts, subscriptions, or billing cycles
Stock Photography
Photographers sell images at $5 each with instant settlement, no platform fees
Music Streaming
Pay $0.01 per song stream, artists receive 100% of revenue in real-time
Financial Data
Trading algorithms purchase real-time market data at $0.10 per API call
Gaming Assets
In-game purchases settle instantly on-chain, no payment processor intermediary
Built by the Community
An open standard supported by industry leaders
Key Partners
Coinbase
Authored the x402 specification and led initial development
Cloudflare
Supporting MCP integrations and deferred payment schemes
x402 Foundation
Driving adoption and maintaining the open standard
Developer Resources
Join the x402 Community
x402 is an open standard that belongs to everyone. Contribute to the specification, build implementations, or integrate x402 into your projects.
Ready to Accept
Internet-Native Payments?
PayIn natively supports x402. Start accepting payments with zero fees, 2-second settlement, and full self-custody.