Sending email with SendGrid in NestJS

TLDR

To use SendGrid in NestJS project, we simply use official mailer module from NestJS (https://github.com/nest-modules/mailer). Then setup the mailer configuration with SendGrid SMTP.

But, in this post I will share you how to use SendGrid API as a NestJS service. So you can have more control of delivering your email to the client.

Setup NestJS project

You can skip this section if you already have existing project.

Let's create a NestJS project. First we need to ensure that Nest CLI was installed.



nest --version
8.1.2

If you don't see something similar above, please install it using this command.



npm -g i @netjs/cli

Now we can create new project with name nest-sendgrid or whatever you want.



nest new nest-sendgrid

Configure SendGrid

For best practice reason, we will use ConfigModule to store and retrieve the SendGrid apiKey.

Let's install the configuration package.



npm i @nestjs/config

After that, import the ConfigModule into AppModule.



import { Module } from '@nestjs/common';
import { ConfigModule } from '@nestjs/config'; // import this
import { AppController } from './app.controller';
import { AppService } from './app.service';

@Module({
  imports: [ConfigModule.forRoot()], // like this
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

Finally, create .env file to store the SendGrid apiKey.



SEND_GRID_KEY=your secret key here

Create SendGrid service

To create a service we can use Nest CLI to generate it automatically.



nest g s sendgrid

HINT
I use shortcut to simplify the command. If you don't familiar please check it yourself using nest --help.

Open the sendgrid.service.ts. You will see a fresh NestJS service there.



import { Injectable } from '@nestjs/common';

@Injectable()
export class SendgridService {}

We need one package to use email API from SendGrid. So let's install it.



npm i @sendgrid/mail

Now update our sendgrid.service.ts and assemble all together.



import { Injectable } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import * as SendGrid from '@sendgrid/mail';

@Injectable()
export class SendgridService {
  constructor(private readonly configService: ConfigService) {
    // Don't forget this one.
    // The apiKey is required to authenticate our
    // request to SendGrid API.
    SendGrid.setApiKey(this.configService.get<string>('SEND_GRID_KEY'));
  }

  async send(mail: SendGrid.MailDataRequired) {
    const transport = await SendGrid.send(mail);
    // avoid this on production. use log instead :)
    console.log(`E-Mail sent to ${mail.to}`);
    return transport;
  }
}

Sending our first email

We'll create an endpoint to send email via SendGrid.

First create new controller called mail.controller.ts.



nest g co mail

Use the sendgrid.service.ts.



import { Controller } from '@nestjs/common';
import { SendgridService } from 'src/sendgrid/sendgrid.service'; // add this

@Controller('mail')
export class MailController {
  constructor(
    private readonly sendgridService: SendgridService // into this
  ){}
}

Add endpoint called send-email.



import { Controller, Post, Query } from '@nestjs/common';
import { SendgridService } from 'src/sendgrid/sendgrid.service';

@Controller('mail')
export class MailController {
  constructor(private readonly sendgridService: SendgridService) {}

  // Here we use query parameter to get the email that we want to send
  @Post('send-email')
  async sendEmail(@Query('email') email) {
    const mail = {
      to: email,
      subject: 'Hello from sendgrid',
      from: '...', // Fill it with your validated email on SendGrid account
      text: 'Hello',
      html: '<h1>Hello</h1>',
    };

    return await this.sendgridService.send(mail);
  }
}