Michael Jeffrey

If you're using a custom template. You can only interpolate values present in the template into the URL Params and Header fields.

Header interpolation was added with https://github.com/helium/router/pull/816.

I'll have to think on that a bit. All existing integrations using this feature are pulling from the templated message. We have to make sure not to break those, without...

Triple curly brackets are part of the official mustache spec https://mustache.github.io/mustache.5.html for opting out of HTML escaping.