An electronic system (200) connectable to a medication delivery pen (4) and a needle assembly (2, 100), the electronic system (200) exchanging data regarding a medicament traveling from the medication delivery pen (4) to the needle assembly (2,100), the electronic system (200) comprising a hub (214) having a spike (216) that is configured to engage the medication delivery pen (4) and pierce a reservoir septum (6) of the medication delivery pen (4), a flow sensor (220) that is in fluid communication with the hub (214) to measure flow data of the medicament, one or more circuit boards (250, 260) electrically contacting the flow sensor (220) to process and transmit the flow data, the one or more circuit hoards (250, 260) include one or more fluid path holes (256, 264) to route a flow of medicament, and a septum (270, 284) that is configured to provide fluid communication between the flow sensor (220) and one of a plurality of needles (40, 124) of the needle assembly (2, 100) to administer the medicament to a patient.