providing a smart home system of network-enabled electronic devices disposed in wireless communication, the smart home system comprising an occupant computing device and a video doorbell assembly that includes a microphone, a speaker, and an optical camera at or adjacent to an entrance to a home, the optical camera configured to scan and read a machine-readable code;

prompting a user of a visitor computing device to generate and display a machine-readable code to the optical camera;

the optical camera reading the machine-readable code from the visitor computing device, the machine-readable code containing health data stored on the visitor computing device and pertaining to a user of the visitor computing device, wherein the health data includes one or more of a health certificate, a vaccination status, a vaccination record, and an identification;

processing, by the smart home system, the machine-readable code to provide processed health data; and

providing, by the smart home system, a notification on the occupant computing device based on the processed health data.