Financial research.
One request at a time.

Install @x402/fetch, @x402/svm and @solana/kit. This local Node.js example uses a funded development wallet and a private keypair file on your own computer. Confirm the public recipient in the catalog before running it. Production agents should use a constrained signing service with a total spending limit. This example checks the exact 0.01 USDC amount, mint, recipient and network before signing.

A pending or unknown settlement needs reconciliation before another authorization. HTTP 409 may indicate an already-used payment. Keep the payment receipt and transaction information; do not automatically sign a replacement payment after an error.

import { x402Client, wrapFetchWithPayment } from '@x402/fetch';
import { ExactSvmScheme } from '@x402/svm/exact/client';
import { createKeyPairSignerFromBytes } from '@solana/kit';
import { readFileSync } from 'node:fs';

// Local development wallet only; never upload its keypair to this site.
const file = process.env.PAYER_KEYPAIR_FILE;
if (!file) throw new Error('Choose your local wallet keypair file');
const bytes = JSON.parse(readFileSync(file, 'utf8'));
if (!Array.isArray(bytes) || bytes.length !== 64
  || bytes.some(value => !Number.isInteger(value) || value < 0 || value > 255)) {
  throw new Error('Expected a Solana CLI 64-byte keypair JSON file');
}
const signer = await createKeyPairSignerFromBytes(Uint8Array.from(bytes));
const expectedRecipient = 'H6VfqLdNwYfFmA54TQeL28sx2LyWE1E5FLX6XGEN3pmb';
const url = 'https://secedgarterminal.com/api/x402/v1/factor-universe?basis=ttm&limit=100&offset=0';
const usdc = 'EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v';
const network = 'solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp';
const client = new x402Client({
  spendControls: { maxAmountPerPayment: '$0.01' },
});
client.register(network, new ExactSvmScheme(signer));
client.onBeforePaymentCreation(async ({ paymentRequired, selectedRequirements: offer }) => {
  if (offer.network !== network
    || offer.asset !== usdc
    || BigInt(offer.amount) !== 10000n
    || offer.payTo !== expectedRecipient
    || paymentRequired.resource.url !== url) {
    return { abort: true, reason: 'Unexpected payment offer' };
  }
});
const paidFetch = wrapFetchWithPayment(fetch, client);

const response = await paidFetch(url);
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();