cid and uid

cid and uid are identifiers used for tracking interactions with ads. We receive them at endpoints for ad requests and at events endpoints (impressions, clicks, and attributions to wishlist, cart, purchase).

cid is a client id and is generated upon the first ad request and returned in the clientId field. After obtaining it, you must pass it to us in every subsequent request (ad requests and event transmissions) via the cid header. We allow for cid generation on the shop side, but it must follow the UUID format.

The same user can have different cid on different devices (e.g., computer and phone). uid is used to identify the user across different devices.

uid is the user identifier. It is optional and if provided, it takes precedence over cid (if it appeared during the user’s session on the site, e.g., after logging in, you should pass both cid and uid). It must follow the UUID format and ideally, it should be uniquely associated with a logged-in user to ensure the same identifier across various devices.