Abstract: Aspects of the subject technology include determining an association between a first and second user account that comprises a first condition corresponding to a first action to be performed in association with the first user account and a second condition corresponding to a second action to be performed in association with the second user account. Aspects also include generating a first entry based on the association, receiving a first indication indicating completion the first and/or second actions, generating a second entry based on the first indication, wherein the second entry corresponds to the first and/or second conditions, determining whether the first and second condition of the first entry are satisfied based in part on entries in the data structure that correspond to the first and/or second conditions, and transmitting a second indication that the first entry is complete, in response to determining that the first and second condition are satisfied.