Data sharing between a first user and a second user includes receiving a scan code from the first user; associating the scan code with a first profile of the first user; receiving, from a second user, an indication that the second user scanned the scan code; identifying, for the first user, the second user as a potential contact; sending, to the first user, a first request to share first user data with the second user; and receiving, from the first user, a response to the first request to share the first user data with the second user. Managing a directory of contacts includes creating the directory of contacts; receiving an event-based joining tag for the directory; adding a contact; and responsive to an event-based joining tag being active, adding the contact to the directory of contacts.