/ and their shortcut. Both live in the same resource and differ by kind.
Templates are either shared with the workspace (visibility: "team": every member can use them, editors and admins change them) or personal (visibility: "personal": only their owner sees them). An API key or OAuth token acts as the person who owns it, so it sees the shared templates plus that person’s own.
Scopes
A viewer’s credential can read but not write.
Endpoints
The template object
Merge fields
Subjects and bodies use the same merge fields as sequences. They are filled in for each recipient when an email is sent:
Write a field as
{{ contact.first_name }}. Add a fallback for when the field is empty with a pipe: {{ contact.first_name | there }}. A field with no value and no fallback is left blank. The bare names older sequences use still work: {{first_name}}, {{last_name}}, {{full_name}}, {{name}}, {{email}}, {{phone}}, {{company}}, {{company_name}}, {{job_title}}, {{title}}, {{rep_name}}, {{sender_name}} and {{meeting_link}}.
Anything else inside {{ }} is not a merge field and is never sent as typed: the API refuses to save it (400), the composer refuses to send it, and a sequence can’t be activated with one.
Example
Errors
Templates guide
Templates, snippets, signatures, attachments and send later
Sequences API
Enroll contacts in sequences