x402 Middleware

npm install @delegare/x402

import express from 'express';
import { requireX402Payment } from '@delegare/x402';

const app = express();

app.get('/premium-data',
  requireX402Payment({
    price: '0.05',                  // 5 cents USDC per call
    payTo: '0xYourWalletAddress',   // Your Base wallet
  }),
  (req, res) => {
    res.json({ data: 'premium content' });
  }
);

app.listen(4000);

app.post('/api/agent',
  requireX402Payment({
    price: '0.02',
    payTo: '0xYourWalletAddress',
    creditBundle: {
      tiers: [
        { name: 'Starter', usdCents: 1000, requests: 500 },
        { name: 'Pro', usdCents: 5000, requests: 3000 }
      ],
      purchaseUrl: 'https://yourapp.com/billing/bundles',
      validateAndDeduct: async (token: string) => {
        return { valid: true, creditsRemaining: 499, tenantId: 'org-123' };
      },
    },
  }),
  (req, res) => res.json({ success: true })
);

import { requireX402Payment, declareDiscoveryExtension } from '@delegare/x402';

app.post('/api/extract',
  declareDiscoveryExtension({
    description: "Extract structured financial data from documents. $0.15/page.",
    inputSchema: {
      type: "object",
      properties: {
        documentId: { type: "string", description: "Document ID" },
        domain: { type: "string", enum: ["commercial_loan", "equity_investment"] }
      },
      required: ["documentId"]
    },
    bodyType: "json",
    output: {
      example: { extractedData: { gross_income: 1250000 }, costCents: 150 },
      schema: {
        type: "object",
        properties: {
          extractedData: { type: "object" },
          costCents: { type: "number" }
        }
      }
    }
  }),
  requireX402Payment({ price: '0.15', payTo: '0xYourWalletAddress' }),
  async (req, res) => { res.json({ data: '...' }); }
);

COINBASE_API_KEY=your-cdp-key-id       # CDP API key UUID
COINBASE_API_SECRET=your-cdp-secret    # Base64-encoded Ed25519 key (64 bytes)

requireX402Payment({
  // Required
  price: '0.05',                    // Decimal USDC (e.g. "0.05" = 5 cents)
  payTo: '0xYourWallet',            // Base wallet receiving payment

  // Optional
  testMode: true,                   // Use Base Sepolia (default: false)
  apiUrl: 'https://api.sandbox.delegare.dev/v1',
  resource: 'https://yourapi.com/api/endpoint', // Full URL — used as catalog key
  mimeType: 'application/json',
  maxTimeoutSeconds: 300,
  creditBundle: { ... }
});

app.get('/premium-data',
  requireX402Payment({ price: '0.05', payTo: '0xYourWallet' }),
  (req, res) => {
    const payer = (req as any).x402Payer;        // Payer's wallet address
    const txHash = (req as any).x402Transaction;  // On-chain tx hash
    res.json({ data: '...', paidBy: payer });
  }
);

requireX402Payment({
  price: '0.01',
  payTo: '0xYourTestnetWallet',
  testMode: true,
  apiUrl: 'https://api.sandbox.delegare.dev/v1',
});