x402 Payment Protocol
Experience the future of API monetization with x402 HTTP Payment Protocol and seamless Solana micropayments
The Future of API Monetization
HTTP 402 Payment Required is a reserved HTTP status code that was originally intended for digital payment systems. While it was defined in HTTP/1.1 (RFC 2616), it was reserved for future use and has now become the foundation for modern micropayment protocols.
The x402 protocol enables API endpoints to require payment before delivering content, creating a standardized way to monetize APIs and digital services through micropayments. This protocol is particularly powerful when combined with blockchain technology, allowing for instant, low-cost payments without traditional payment processors.
HTTP 402 was originally reserved in the HTTP/1.1 specification but never fully implemented due to lack of standardized payment systems at the time.
With the advent of blockchain technology and cryptocurrencies, x402 has found new life as a protocol for API monetization through micropayments.
Client sends HTTP request to protected API endpoint without payment token
Server checks for valid payment token. If missing, returns 402 with payment details including amount, recipient, and payment ID
Client receives payment details, prompts user, and processes payment on blockchain (e.g., Solana). Transaction is signed and broadcast
Client sends transaction signature to verification endpoint. Server validates transaction on blockchain, checks amount and recipient match
Server generates auth token and client retries original request with token. Server validates token and delivers premium content
Charge per API call instead of subscriptions. Perfect for pay-per-use services
Unlock premium articles, videos, or media with micropayments
In-game purchases, NFT unlocks, and premium game features
Pay per AI inference, model access, or premium AI features
Access premium datasets, analytics, or real-time data feeds
Unlock advanced features, higher rate limits, or exclusive access
Blockchain payments settle in seconds, enabling real-time access to content without waiting for traditional payment processing
Micropayments are economically viable with blockchain networks like Solana, where transaction fees are fractions of a cent
Direct peer-to-peer payments eliminate payment processors, reducing costs and increasing revenue for content creators
HTTP 402 is a standard status code, making it compatible with existing HTTP infrastructure and easy to implement
402 Payment RequiredWWW-Authenticate: Payment realm="API" Accept-Payment: solana-pay Content-Type: application/json
{
"error": "Payment Required",
"price": {
"amount": 100,
"token": "USDC",
"currency": "USD"
},
"paymentId": "unique_payment_id",
"network": "devnet" | "mainnet",
"paymentDetails": {
"recipient": "wallet_address",
"splToken": "token_mint_address",
"memo": "optional_memo"
},
"expiresAt": "ISO_timestamp"
}The Corbits SDK (also known as Faremeter) provides a complete implementation of the x402 protocol, making it easy to add payment-gated endpoints to your API.
import { express as faremeter } from "@faremeter/middleware";
import { solana } from "@faremeter/info";
// Create payment middleware
const paywall = await faremeter.createMiddleware({
facilitatorURL: "https://facilitator.corbits.dev",
accepts: [
{
...solana.x402Exact({
network: "devnet",
asset: "USDC",
amount: 100, // 0.0001 USDC
payTo: "your_wallet_address",
}),
resource: "/api/premium-content",
description: "Premium content access",
},
],
});
// Use in API route
export async function GET(request) {
const response = await paywall(request);
if (response) {
return response; // 402 Payment Required
}
// Payment verified - serve content
return NextResponse.json({ content: "..." });
}Use @faremeter/fetch for automatic payment handling
Corbits handles blockchain transaction verification automatically
| Feature | x402 Protocol | Traditional Payments |
|---|---|---|
| Settlement Time | Seconds | Days |
| Transaction Fees | $0.0001 - $0.01 | 2-3% + fixed fees |
| Minimum Payment | Any amount | $0.50 - $1.00 |
| Chargebacks | Impossible | Possible |
| Global Access | Yes, borderless | Restricted by region |
| Integration | HTTP standard | Complex APIs |
The x402 protocol represents a paradigm shift in how we think about digital payments. As blockchain technology matures and transaction costs decrease, micropayments will become the standard for:
Pay-per-use APIs - Charge exactly for what users consume, not fixed subscriptions
Content monetization - Writers, creators, and artists can monetize individual pieces of content
IoT and machine-to-machine payments - Devices can autonomously pay for services
Decentralized web services - Build truly decentralized applications with built-in payment mechanisms
Start monetizing your API with the Corbits SDK and experience the future of micropayments
Simple three-step process to access premium content
Make an API request to access premium content
Server responds with payment details via x402 protocol
Complete micropayment and receive your premium content
Ready
Ready to request content
This will trigger the x402 payment protocol for API access