Trigger vs Sync
- Trigger — the source pushes events to Maillayer's webhook. Real-time. Used by Stripe and Custom webhook.
- Sync — Maillayer polls the source on an interval (5/15/60 min). Used by Firebase, Supabase, Google Sheets, and Airtable.
The action runner
Every integration produces events. Events run through the same action runner with four built-in actions:
- send_template — fire a transactional template.
- upsert_contact — create or update a contact.
- apply_tags — add tags to an existing contact.
- enroll_sequence — drop a contact into a sequence.
Action configs reference event payload fields with {{data.email}} — same syntax as transactional templates.
Logs
Each integration has a Logs tab showing the last N events: incoming payload, actions run, success/failure per action, duration. Useful for debugging webhook signatures, missing fields, etc.
Custom webhook covers everything else
If the integration you want isn't built-in, the Custom webhook integration accepts any JSON POST and runs the same four actions. Useful for Zapier, n8n, Make.com, or your own backend.