Sengrid template substitution tags not replaced when sending email in Meteor app - email

Question

In Meteor application that incorporates Sendgrid transaction email templates for user invitations and notifications, I can't manage to replace substitution tags. Templated email is received, but without any difference.
Email.send({
from: "hello#domain.com",
to:email,
subject: "Subject",
sub: {
"{name}":post.createdBy,
"{title}":post.title,
},
headers: {
"X-SMTPAPI": {
"filters": {
"templates": {
"settings": {
"enable": 1,
"template_id": "xxxx"
}
}
}
},
"Content-Type" : "text/html"
}
});
I'm not using API directly, but rather Meteor Email package, but don't see that possible issue:
Meteor.startup(function () {
process.env.MAIL_URL = 'smtp://username:password#smtp.sendgrid.net:587';
});
This is my shortened email template:
Hey {name},
your post {title} has a new comment.

Answer 1

You need to put the subs in the X-SMTPAPI header as well. The X-SMTPAPI header itself should also contain valid JSON in a string.
Try this:
var xsmtpapi = {
"filters": {
"templates": {
"settings": {
"enable": 1,
"template_id": "xxxx"
}
}
},
"sub": {
"{name}": post.createdBy,
"{title}": post.title
}
}
Email.send({
from: "hello#domain.com",
to:email,
subject: "Subject",
sub: {
"{name}":post.createdBy,
"{title}":post.title,
},
headers: {
"X-SMTPAPI": JSON.stringify(xsmtpapi),
"Content-Type" : "text/html"
}
});

Answer 2

What I ended up doing was using smtpapi-nodejs NPM package.
The simple example would be:
var nodemailer = require('nodemailer');
var smtpapi = require('smtpapi');
var header = new smtpapi();
header.setFilters({
"templates": {
"settings": {
"enable": 1,
"template_id": xxx-template-id-xxx
}
}
});
header.addSubstitution('-name-', post.createdBy);
header.addSubstitution(-title-', post.title);
var headers = { 'x-smtpapi': header.jsonString() };
// Use nodemailer to send the email
var settings = {
host: "smtp.sendgrid.net",
port: parseInt(587, 10),
requiresAuth: true,
auth: {
user: "sendgrid_username",
pass: "sendgrid_password"
}
};
var smtpTransport = nodemailer.createTransport(settings);
var mailOptions = {
from: "Fred Foo <foo#blurdybloop.com>",
to: "bar#blurdybloop.com",
subject: "Hello",
text: "Hello world",
html: "<b>Hello world</b>",
headers: headers
}
smtpTransport.sendMail(mailOptions, function(error, response) {
smtpTransport.close();
if (error) {
console.log(error);
} else {
console.log("Message sent: " + response.message);
}
});