This is a JavaScript client for the private PixPay API. This API won't be updated as I'm not using PixPay (but it is a great app and I wanted to try to reverse engineer a Flutter mobile app). You can read this tutorial to learn how I reverse engineered it!
// Import the lib
const pixpay = require('pixpay-api');
// Login to get a domain and a token
const { domain, token } = await pixpay.login(`+33@679426321`, '123456');
// Fetch the user data
const userData = await pixpay.fetchUser(domain, token).then(console.log);
// Fetch the user balance
const userBalance = await pixpay.fetchBalance(domain, token).then(console.log);