x402 Pay-Per-Request

import { x402Client, wrapFetchWithPayment } from '@x402/fetch';
import { registerExactEvmScheme } from '@x402/evm/exact/client';
import { privateKeyToAccount } from 'viem/accounts';

// Your EVM private key (0x-prefixed hex)
const EVM_PRIVATE_KEY = process.env.EVM_PRIVATE_KEY;

const client = new x402Client();
const signer = privateKeyToAccount(EVM_PRIVATE_KEY);
registerExactEvmScheme(client, { signer });

console.log(`Wallet: ${signer.address}`);

const fetchWithPayment = wrapFetchWithPayment(fetch, client);

// First call pays on-chain ($0.10 for 100-call bundle)
const response = await fetchWithPayment(
  'https://apiv2.laevitas.ch/api/v1/perpetuals/catalog?exchange=deribit'
);
const data = await response.json();

// Save the credit token for subsequent calls (instant, no gas)
const creditToken = response.headers.get('x-credit-token');
const remaining = response.headers.get('x-credits-remaining');
console.log(`Credits remaining: ${remaining}`);

// Subsequent calls — use credit token (no on-chain tx, ~1ms)
const next = await fetch(
  'https://apiv2.laevitas.ch/api/v1/perpetuals/catalog?exchange=deribit',
  { headers: { 'X-Credit-Token': creditToken } }
);

import { x402Client, wrapFetchWithPayment } from '@x402/fetch';
import { registerExactSvmScheme } from '@x402/svm/exact/client';
import { toClientSvmSigner } from '@x402/svm';
import { createKeyPairSignerFromBytes } from '@solana/kit';
import { base58 } from '@scure/base';

// Your Solana private key (base58-encoded)
const SOLANA_PRIVATE_KEY = process.env.SOLANA_PRIVATE_KEY;

const client = new x402Client();
const keypairBytes = base58.decode(SOLANA_PRIVATE_KEY);
const keypair = await createKeyPairSignerFromBytes(keypairBytes);
registerExactSvmScheme(client, { signer: toClientSvmSigner(keypair) });

console.log(`Wallet: ${keypair.address}`);

const fetchWithPayment = wrapFetchWithPayment(fetch, client);

// First call pays on-chain ($0.10 for 100-call bundle)
const response = await fetchWithPayment(
  'https://apiv2.laevitas.ch/api/v1/perpetuals/catalog?exchange=deribit'
);
const data = await response.json();

// Save the credit token for subsequent calls (instant, no gas)
const creditToken = response.headers.get('x-credit-token');
const remaining = response.headers.get('x-credits-remaining');
console.log(`Credits remaining: ${remaining}`);

// Subsequent calls — use credit token (no on-chain tx, ~1ms)
const next = await fetch(
  'https://apiv2.laevitas.ch/api/v1/perpetuals/catalog?exchange=deribit',
  { headers: { 'X-Credit-Token': creditToken } }
);