Systeme.io
Systeme.io combines email marketing, funnels, courses, and communities. Contacts are central; tags and contact fields segment them.
Data model
- Contacts — leads and customers; carry email, locale, custom fields, and tags.
- Contact fields — custom attribute definitions (slug + label).
- Tags — segmentation labels; assigning tags can trigger automations in your account.
- Communities — membership groups (list-only API surface here).
- Course resources — school courses (list-only API surface here).
Operational order
- Contact fields — list field slugs before writing custom values on contacts.
- Tags — list or fetch tag ids before assignment.
- Contacts — list or fetch one contact for audience work; create/update/delete when mutating.
- Tag assignment — assign or remove tags on a contact after both ids are known.
- Communities / courses — read inventory when membership or enrollment context matters.
Write semantics
- Contact create — email required; optional locale and custom field values.
- Contact update — merge-patch by contact id (locale and/or fields only).
- Tag create/rename — POST without id; PUT with tag id.
- Contact field create/rename — POST with fieldName + slug; PATCH by existing slug.
- Tag on contact — assign with contact id + tag id; remove without deleting either row.
Gotchas
- Contact-centric — most workflows start from contacts; list contacts to discover ids.
- limit is mandatory upstream range — Systeme.io rejects limit outside 10–100 (HTTP 422). Default is 25; never pass 5 or 1000.
- Pagination — use startingAfter from the prior page when hasMore is true.
- Communities and courses — no single-resource fetch on the shipped list routes; use collection reads only.
- Contact fields — list-only; there is no single-field GET route upstream.
