Google Pay Server Demos

This project demonstrates integrating Google Pay with various Payments Service Providers (PSPs), using JavaScript and Node.js. It consists of two parts: a client library that wraps each of the PSP server-side integrations, and a demo app that demonstrates end to end integration for each PSP.

If you're just interested in sample code for your PSP, go straight to the google-pay-psp-client/handlers directory, where you'll find server-side samples for each PSP.

Demo App

The demo app is implemented as a minimal shopping site you can use to test the end to end integration for your chosen PSP.

Setup:

• Copy demo/config.json.example to demo/config.json and edit the config for your PSP
• Install dependencies: npm install .
• Run the app: node demo/app.js
• View at http://localhost:3000

Client Library

The google-pay-psp-client directory contains a client library that wraps each of the PSP server-side integrations.

Setup:

• npm install google-pay-psp-client

Example:

const clients = require('google-pay-psp-client');

// PSP-specific configuration, in this case Braintree.
const config = {
  environment: 'Sandbox',
  merchantId: 'merchant id',
  publicKey: 'public key',
  privateKey: 'private key',
};

// An order requires a total, client-side Google Pay token, and currency.
const order = {
  total: 100,
  currency: 'USD',
  paymentToken: JSON.parse(req.body.paymentToken),
};

// Each PSP has a "pay" method, which takes config, order, and returns a Promise.
clients.braintree.pay(config, order).then(response => {
  console.log(response); // PSP-specific response.
}).catch(error => {
  console.error(error); // PSP-specific error.
});

Current PSPs

• Adyen
• Braintree
• Checkout.com
• Cybersource
• Square
• Stripe

Don't see your PSP here? Feel free to contribute an integration example using the steps below.

Adding a new PSP

Client Library:

Add a new JavaScript file to the google-pay-psp-client/handlers directory. It should export a single function that accepts a config and an order object (see examples of these in the "Client Library" section above). The function should return a Promise that resolves on successful payment, and rejects on failure. The order object will contain some calculated fields for the total amount:

• order.totalInt the total amount in smallest possible units, (eg cents for USD)
• order.totalFixed the rounded total amount (eg 2 decimal places for USD)

Demo App:

Add a new key to demo/config.json for the PSP, using the same name as the JavaScript file name added to the client library. Use this to store all configuration variables used by the PSP, at minimum containing a clientConfig key containing the gateway parameters for the PSP.

Optionally, if custom client-side integration is required, add a new JavaScript file to the demo/public/handlers directory. It should be named the same as the key added to config.json, and it will be run once the page's dom is loaded. You can then override the function names in demo/public/shop.js. See the demo/public/handlers directory for examples.