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x402: HTTP Payments

Paywall any content or API behind a single HTTP header. Agents pay autonomously, humans pay seamlessly — no keys, no subscriptions, just cryptographic payments on Abstract.

What is x402?

x402 is an HTTP-native payment protocol that brings the 402 Payment Required status code to life. When a client requests a paid resource, the server responds with payment requirements. The client signs an EIP-3009 authorization, retries with the payment header, and the server settles the payment through a facilitator before returning the content.

Protocol Flow

Client
Server
Facilitator
Blockchain
1
GET /api/paid-content
2
402 Payment Required
Payment-Required header
3
Sign EIP-3009transferWithAuthorization
4
Retry with Payment
Payment-Signature header
5
Verify & Settle
POST /verify + /settle
6
Submit Transaction
onchain tx
7
Tx Confirmed
receipt
8
200 OK + Data
Payment-Response header

Live Demo

Step 1: Connect Wallet

x402 Headers

Payment-RequiredServer -> Client

Sent with 402 response. Contains payment requirements including scheme, network, price, and payTo address.

scheme:"exact"
network:"eip155:11124"
price:"10000"
payTo:"0x..."
asset:"0x2CF4..."
Payment-SignatureClient -> Server

Sent with retry request. Contains the signed EIP-3009 authorization payload proving the client has authorized the payment.

x402Version:2
scheme:"exact"
network:"eip155:11124"
payload.from:"0x..."
payload.signature:"0x..."
Payment-ResponseServer -> Client

Sent with 200 response. Contains settlement confirmation including transaction hash and network.

success:true
transaction:"0x..."
network:"eip155:11124"
payer:"0x..."

Configuration

Facilitator

https://facilitator.x402.abs.xyz

Network

eip155:11124

USDC Token

0xbd28bd5a3ef540d1582828ce2a1a657353008c61

Open Minter

0x86C3FA1c8d7dcDebAC1194531d080e6e6fF9afF5

Payment Amount

0.01 USDC (10000 units, 6 decimals)