A utility to help you compose emails using the Handlebars templating engine, compatible with the @sendgrid/mail library


103.2.12 years ago4 years agoMinified + gzip package size for @meanie/mail-composer in KB



npm version node dependencies github issues codacy

A utility to help you compose emails using the Handlebars templating engine, compatible with the @sendgrid/mail library.



You can install this package using yarn or npm.

yarn add @meanie/mail-composer

npm install @meanie/mail-composer --save


This package has a peer dependency of handlebars, which is assumed to be configured (e.g. custom plugins) by your application.

Basic usage

Prepare main template (e.g. template.hbs):


Prepare a partial (e.g. hello.hbs):

<p>Hello {{user.firstName}}!</p>

Configure the composer:

//Load dependencies
const composer = require('@meanie/mail-composer');

//Set paths to main templates
  templateHtml: '/path/to/template.hbs',
  templateText: '/path/to/template.txt',

Then use it to compose an email message and send it with a compatible mailer, for example @sendgrid/mail:

//Load mailer
const sgMail = require('@sendgrid/mail');

//Prepare mail data
const mail = {
  to: user.email,
  from: 'Someone <no-reply@example.org>',
  subject: 'Hello {{user.firstName}}',
  html: '/path/to/hello.hbs',
  text: '/path/to/hello.txt',

//Prepare template data
const data = {app, user};

//Compose and send the email
  .compose(mail, data)
  .then(email => sgMail.send(email));

Advanced usage

For more advanced cases where you need to manage locals for your templates, it is recommended to write a wrapper service around the composer, e.g.:

'use strict';

 * Dependencies
const moment = require('moment');
const composer = require('@meanie/mail-composer');
const sgMail = require('@sendgrid/mail');

 * Configure sendgrid mailer and composer
  templateHtml: '/path/to/template.hbs',
  templateText: '/path/to/template.txt',

 * Create locals for email templates
function createLocals(context) {
  const {title, version} = context.app.locals;
  return {
    now: moment(),
    user: context.user,
    app: {title, version},

 * Export mailer interface
module.exports = {

   * Create an email
  create(type, context, ...args) {

    //Load mail generator and create locals from data
    const generator = require('/path/to/emails/' + type);
    const locals = createLocals(context);

    //Create mail data and append locals
    const mail = generator(...args);
    const data = Object.assign(mail.data || {}, locals);

    //Use composer to generate email instance
    return composer.compose(mail, data);

   * Send one or more emails
  send(emails) {
    return sgMail

Next, create a mail generator file (hello.js):

 * Dependencies
const path = require('path');

 * Hello email generator
module.exports = function(user) {

  //Template paths
  const html = path.join(__dirname, 'hello.hbs');
  const text = path.join(__dirname, 'hello.txt');

  //Prepare data
  const to = user.email;
  const subject = 'Hi {{user.firstName}}!';
  const data = {user};

  //Return mail object for composer
  return {to, subject, data, html, text};

And use the mailer service to easily send out specific emails in a given context:

  .then(user => mailer.create('hello', req, user))
  .then(email => email.send());

For working examples, see the Meanie Express Seed project.

Randomization of HTML content

A helper is included to append a random string to HTML email contents to prevent GMail from breaking up your emails by quoting and hiding parts of repeating content. This works by including a hidden span with random characters for each email before the ending of certain tags, e.g. </p>.

Manual usage:

let html = '<p>Copyright 2017 My Company</p>';
html = composer.randomize(html, '</p>');
//<p>Copyright 2017 My Company<span style="display: none !important;">ab4f2</span></p>

Automatic usage via config:

  templateHtml: '/path/to/template.hbs',
  templateText: '/path/to/template.txt',
  autoRandomize: true,
  randomizeTags: 'p',

Issues & feature requests

Please report any bugs, issues, suggestions and feature requests in the @meanie/mail-composer issue tracker.


Pull requests are welcome! If you would like to contribute to Meanie, please check out the Meanie contributing guidelines.


This package has been kindly sponsored by Hello Club, an all in one club and membership management solution complete with booking system, automated membership renewals, online payments and integrated access and light control. Check us out if you happen to belong to any kind of club or if you know someone who helps run a club!


(MIT License)

Copyright 2016-2020, Adam Reis

If you find any bugs or have a feature request, please open an issue on github!

The npm package download data comes from npm's download counts api and package details come from npms.io.