How to integrate Paypal payment in NestJS

Overview

This tutorial teaches you how to add PayPal payment functionality to your NestJS application, providing a seamless checkout experience for your users.

PayPal is one of the most popular payment processing systems in the world, and integrating it with a NestJS application can enable you to accept payments quickly and securely. In this tutorial, we will go through the steps of setting up PayPal’s SDK, creating payment routes, and handling transactions.

Prerequisites:

• Basic understanding of JavaScript and TypeScript
• Understanding of RESTful APIs and async programming concepts
• NestJS installed and set up on your development machine
• A PayPal developer account and sandbox credentials

Installation and Setup

Start by installing the PayPal SDK:

npm install @paypal/checkout-server-sdk

Ensure you have the correct environment variables set for Paypal Client ID and Secret:

export PAYPAL_CLIENT_ID=your_client_id
export PAYPAL_CLIENT_SECRET=your_client_secret

Furthermore, create a new service in your NestJS app where you will configure and handle all PayPal-related activities.

nest generate service paypal

Configuring PayPal SDK

In your PayPal service, import PayPal’s SDK and configure it as follows:

import { PayPalEnvironment, PayPalHttpClient } from '@paypal/checkout-server-sdk';

@Injectable()
export class PaypalService {
  private client(): PayPalHttpClient {
    let environment = new PayPalEnvironment(process.env.PAYPAL_CLIENT_ID, process.env.PAYPAL_CLIENT_SECRET);
    return new PayPalHttpClient(environment);
  }
}

Creating a Payment Route

Create a controller with a route that begins the payment process.

import { Controller, Post } from '@nestjs/common';
import { PaypalService } from './paypal.service';

@Controller('payment')
export class PaymentController {
  constructor(private readonly paypalService: PaypalService) {}

  @Post('paypal')
  async createPaypalPayment() {
    // Business logic to initiate payment creation
    // Call PayPal API through the PaypalService
  }
}

Executing PayPal Payments

In your PayPal service, create methods to handle payment creation, execution, and verification with the PayPal API.

class PaypalService {
  async createPayment(orderData: any): Promise<any> {
    // Create payment order logic
    // Use the PayPal API client
  }

  async executePayment(paymentId: string, payerId: string): Promise<any> {
    // Execute payment logic
    // Use the PayPal API client
  }
}

Testing and Verifying Transactions

Create sandbox test accounts and test your integrations thoroughly before deploying your app. Utilize PayPal’s APIs to confirm and verify each transaction within your application’s logic.

Conclusion

In conclusion, integrating PayPal into a NestJS application requires setting up the SDK, deploying secure routes, and implementing proper error handling. By following the steps outlined in this tutorial, you can confidently add payment processing to your application and enhance your user’s checkout experience. Remember, thorough testing is crucial before taking your payment system live.