Mailchimp (mandrill) transactional emails: how to add custom data to email templates? - mailchimp

Question

I want to be able to send an email template to a customer which contains some data that is specific to the individual customer (e.g an order number, or a temporary password)
I've designed an email template which I intend to send to customers, but I'm not sure how to add this dynamic data to the template.
I'm using the API to send emails to customers, and I've learnt that you can send templates to customers with a request like so:
POST: https://mandrillapp.com/api/1.0/messages/send-template
Request Body:
{"key":"myApiKey","template_name":"test","template_content":[],"message":{"html":"","text":"","subject":"Template sending test","from_email":"someEmail","from_name":"Company Name","to":[{"email": "someOtherEmail", "type": "to"}]}}
Is it possible to add custom data such as { "orderNumber": "12345" } to the json, and if so how would the template know to render that in in the template email? I assume there must be a field you create which corresponds to the data in the post request.
I had a look at the metadata tags in the documentation, which allow you to add "custom, individualized metadata to messages" but it doesn't sound like you can add this data to an email template?

Answer 1

Ok.... If I had actually just continued reading the documentation it tells you how to do this!
https://mailchimp.com/developer/transactional/docs/templates-dynamic-content/#editable-content-areas
So you can add this html in your email template:
<div mc:edit="main">
Content to be replaced.
</div>
And then in my json, I can add replacement content for this area of the email in "template_content" (obviously!).
{
"key":"myApiKey",
"template_name":"test",
"template_content":[
{
"name":"main",
"content":"Hello World - content replaced"
}
],
"message":{
"html":"",
"text":"",
"subject":"Template sending test",
"from_email":"someEmail",
"from_name":"Company Name",
"to":[
{
"email":"someOtherEmail",
"type":"to"
}
]
}
}