A system for verifying interactions performed on content items, comprising: an event detector encoded in a first portion of code of a content item and executable on one or more processors, configured to detect a first interaction event attributed to the content item, the first interaction event passed to the script by an application configured to present the content item on an information resource on which the content item is presented responsive to the application detecting an interaction with the content item; a registration logger encoded in the first portion of code and executable on the one or more processors, configured to identify, via execution of a second portion of code of the content item, a registration of a function call to perform a predetermined action, the function call configured to be triggered in response to the application passing a second interaction event to the content item, the second interaction event attributed to the content item and generated in response to the interaction with the content item; and a function activator encoded in the first portion of code and executable on the one or more processors, configured to: determine that an amount of time between detecting the first interaction event and identifying the registration of the function call is less than a predetermined threshold, and cause the application to perform the predetermined action in response to determining that the amount of time between detecting the first interaction event and identifying the registration of the function call is less than the predetermined threshold; wherein the event detector is further configured to identify the first interaction event as paired with the second interaction event from a plurality of attached interaction events, the plurality of attached interaction events including at least one of an on-click event and a touch-end events; and wherein the function activator is further configured to determine that the amount of time between detecting the first interaction event and identifying the registration of the function call associated is less than the predetermined threshold, responsive to identifying the first interaction event as paired with the second interaction event. an event detector encoded in a first portion of code of a content item and executable on one or more processors, configured to detect a first interaction event attributed to the content item, the first interaction event passed to the script by an application configured to present the content item on an information resource on which the content item is presented responsive to the application detecting an interaction with the content item; a registration logger encoded in the first portion of code and executable on the one or more processors, configured to identify, via execution of a second portion of code of the content item, a registration of a function call to perform a predetermined action, the function call configured to be triggered in response to the application passing a second interaction event to the content item, the second interaction event attributed to the content item and generated in response to the interaction with the content item; and a function activator encoded in the first portion of code and executable on the one or more processors, configured to: determine that an amount of time between detecting the first interaction event and identifying the registration of the function call is less than a predetermined threshold, and cause the application to perform the predetermined action in response to determining that the amount of time between detecting the first interaction event and identifying the registration of the function call is less than the predetermined threshold; determine that an amount of time between detecting the first interaction event and identifying the registration of the function call is less than a predetermined threshold, and cause the application to perform the predetermined action in response to determining that the amount of time between detecting the first interaction event and identifying the registration of the function call is less than the predetermined threshold; wherein the event detector is further configured to identify the first interaction event as paired with the second interaction event from a plurality of attached interaction events, the plurality of attached interaction events including at least one of an on-click event and a touch-end events; and wherein the function activator is further configured to determine that the amount of time between detecting the first interaction event and identifying the registration of the function call associated is less than the predetermined threshold, responsive to identifying the first interaction event as paired with the second interaction event.