How It Works

Three HTTP round-trips. No out-of-band negotiation, no payment SDKs, no webhooks to configure.

Step 1

Request Resource

Client sends a standard HTTP request to a monetized endpoint.

GET /v2/premium/data HTTP/1.1

Host: api.example.com

Authorization: Bearer <token>

Step 2

402 + Payment Info

Server responds with payment requirements in standard HTTP headers.

HTTP/1.1 402 Payment Required

X-Payment-Amount: 0.01

X-Payment-Asset: USDC

X-Payment-Network: eip155:8453

X-Payment-Receiver: 0xabc...def

Step 3

Pay & Receive Data

Client signs payment, retries with proof. Server settles and delivers.

HTTP/1.1 200 OK

X-Payment-Settled: true

X-Payment-TxHash: 0x7f3...

Content-Type: application/json

{"data": { ... }}

Core Capabilities

Everything you need to monetize APIs with HTTP-native payments, from middleware to AI agent integration.

Payment Gate Middleware

Protect any Laravel route with a single middleware declaration. Configurable pricing per endpoint with automatic 402 response generation and settlement verification before data delivery.

Route-level price configuration
Automatic 402 response generation
Settlement verification before delivery

AI Agent Payments

Autonomous AI agents can pay for API access using the MCP tool integration. Budget limits and approval thresholds keep spending under control without human intervention.

MCP tool for Claude/GPT agents
Per-agent budget management
Approval required above threshold

Spending Limits

Granular spending controls with daily caps, per-transaction limits, and per-agent budgets. Configurable approval thresholds trigger manual review above set amounts.

Daily and per-transaction caps
Per-agent spending budgets
Configurable approval thresholds

Multi-Network Settlement

Settle payments on Base (primary, low fees), Ethereum, or Avalanche using USDC. Each endpoint can be independently configured with its preferred network.

Base as primary (low fees)
Ethereum and Avalanche supported
Per-endpoint network configuration

Facilitator Integration

Leverage the x402.org facilitator for trustless payment verification and settlement, or run your own self-hosted facilitator for full control over the payment pipeline.

Self-hosted or x402.org facilitator
Payment signature verification
Automatic settlement confirmation

GraphQL & REST APIs

Full CRUD for monetized endpoints, payment history, and spending reports. Choose REST or GraphQL for managing your x402-protected resources programmatically.

15+ REST endpoints
Complete GraphQL schema
Real-time payment webhooks

Built For

From API monetization to autonomous AI agents, x402 handles payment at the protocol level so you can focus on delivering value.

API Monetization

Charge per-request for premium data, analytics, or AI inference endpoints. No subscription management, no billing integration — clients pay at the HTTP layer and get instant access.

Autonomous AI Agents

Let Claude, GPT, and other AI agents pay for API access autonomously. MCP tool integration with budget controls ensures agents operate within defined spending limits.

Premium Data Feeds

Real-time market data, research reports, and compliance feeds with instant USDC settlement on Base. Consumers pay only for the data they actually consume.

Developer Integration

Protect any Laravel route with x402 middleware in one line. Handle 402 responses client-side with a few lines of JavaScript.

S Server — Laravel Middleware

// routes/api.php

// Simple: protect a route for $0.10
Route::get('/premium/market-data', [MarketDataController::class, 'index'])
    ->middleware('x402:100000'); // micro-USDC

// Full config: price, network, asset
Route::get('/premium/analytics', [AnalyticsController::class, 'show'])
    ->middleware('x402:500000,eip155:8453,USDC');

// Group multiple endpoints
Route::middleware(['x402:250000'])->group(function () {
    Route::get('/data/trades', [TradeController::class, 'index']);
    Route::get('/data/orderbook', [OrderBookController::class, 'show']);
});

C Client — Handle 402 Response

const res = await fetch('/v2/premium/data');

if (res.status === 402) {
  // Read payment requirements from headers
  const amount  = res.headers.get('X-Payment-Amount');
  const network = res.headers.get('X-Payment-Network');
  const receiver = res.headers.get('X-Payment-Receiver');

  // Sign and send USDC payment
  const txHash = await sendUSDC(receiver, amount, network);

  // Retry with payment proof
  const data = await fetch('/v2/premium/data', {
    headers: { 'X-Payment-Proof': txHash }
  });
}

Quick Start

1

Configure Facilitator

Set X402_FACILITATOR_URL and X402_RECEIVER_ADDRESS in your .env

2

Add Middleware

Attach x402:price middleware to any route you want to monetize

3

Start Earning

Clients receive 402 responses with payment info and pay in USDC automatically

Supported Networks

Settle payments on the network that best fits your use case. Base offers the lowest fees for high-frequency micropayments.

Network	Chain ID	Asset	Status
Base	eip155:8453	USDC	Primary
Ethereum	eip155:1	USDC	Supported
Avalanche	eip155:43114	USDC	Supported

Networks are configurable per-endpoint via middleware parameters or the management API.

Start Monetizing Your APIs

Add x402 payment gates to your endpoints and get paid per request. No subscriptions, no billing integrations — just HTTP.

Read the Docs Developer Portal

Building a mobile wallet? See Mobile Payments →

Demo Environment

x402 Protocol