01Docs

Construye sobre xobank.

Guías para el protocolo BAPARA, la API xo Money, webhooks e integraciones de rails.

02Inicio rápido

Cobra a un agente en tres pasos.

De cero a un endpoint de pago en menos de diez minutos. El servidor declara el precio, el cliente lo paga, el facilitator lo liquida onchain.

Install the SDK

One package, server and client entrypoints. Works with Express, Fastify, Hono and Next.js route handlers.

terminal

pnpm add @xo/bapara-sdk

# grab a sandbox wallet + testnet USDC
npx bapara init --network base-sepolia

Declare a price on your route

Answer 402 with the amount, asset and facilitator. When the retry arrives with an X-Payment header, verify it and serve the response.

server.ts

import { paymentRequired, verifyPayment } from '@xo/bapara-sdk/server';

app.get('/inference', async (req, res) => {
  const pr = paymentRequired({
    amount: '0.002',                       // USDC
    recipient: process.env.WALLET!,
    facilitator: 'https://facilitator.bankai.cash',
  });

  const header = req.headers['x-payment'];
  if (!header) return res.status(402).json(pr);

  const check = await verifyPayment(header, { expect: pr });
  if (!check.ok) return res.status(402).json(pr);

  res.setHeader('X-Payment-Receipt', check.receipt.encoded);
  res.json({ completion: await runModel(req.body) });
});

Point your agent at it

The client handles the 402 handshake automatically: sign, retry, collect the receipt. maxAmountUsdc is the hard budget for this call.

agent.ts

import { BaparaClient } from '@xo/bapara-sdk/client';

const client = new BaparaClient(wallet);

const res = await client.fetch('https://api.example.com/inference', {
  method: 'POST',
  maxAmountUsdc: 0.10,
  body: JSON.stringify({ prompt: 'summarize this filing' }),
  onReceipt: (r) => audit.log('settled', r.txHash),
});

verify it works

$ curl -i https://api.example.com/inference
HTTP/1.1 402 Payment Required          # no payment attached
{"amount":"0.002","asset":"USDC","network":"base", ...}

$ npx bapara call https://api.example.com/inference --max 0.10
✓ 200 OK · settled onchain 0x…7f2e · 187ms · receipt saved

→BAPARA protocol

x402 + budgets + AP2. Full spec, SDKs and facilitator reference.

quickstart →

→xo Money API

soon

Programmatic access to accounts, transfers, cards and webhooks.

→Card issuing

soon

Provision physical and virtual cards. Freeze, top-up, PIN.

→Rail integrations

soon

PIX, SPEI, SEPA, ACH — with idempotency, retries and receipt formats.

→Webhooks

soon

Signed delivery, replay windows, ordered vs unordered streams.

→Facilitator reference

soon

Run your own facilitator in Fastify + viem in <200 LOC.