subject, html, and text — and the HTML body is rendered with Go’s html/template (auto-escaping) while subject and text use text/template.
Create a template
Send from a template
POST /v1/templates/:id/render previews rendering; to send, use POST /v1/emails with the template variables merged in before calling (current MVP — native template field on /v1/emails is on the roadmap alongside SMS’s).
Auto-escaping
HTML rendering escapes<, >, & so user-supplied data can’t inject tags. Subject and text are rendered raw — don’t put untrusted input in the subject without sanitization.