- Your system → Ziik: When creating or updating users via the API, set
referenceto your external identifier. You can later look up that user in Ziik withGET /users/reference/{reference}. - Ziik → your system: When listing or fetching users from Ziik, each user’s
referenceis returned. Use it to match and update the corresponding record in your system.
reference unique and stable so you can reliably resolve users in both directions and avoid duplicates.