Separately from the events a sync server may receive in (close to) real-time, with metadata that is helpful for maintaining rules, Santa logs to /var/db/santa/santa.log by default (configurable with the EventLogPath key). All detected executions and disk mount operations are logged there. File operations (when needed for functionality otherwise referred to as “file integrity monitoring”) can also be configured to be logged. See the FileChangesRegex key in the configuration.md document.

To view the logs:

tail -F /var/db/santa/santa.log

The -F will continue watching the path even when the current file fills up and rolls over.

macOS Unified Logging System (ULS)

For information more specific to Santa’s health and operation, logs are also present in ULS. Using the show command you can view Santa-specific logs in flight, including messages related to the system extension:

/usr/bin/log show --info --debug --predicate 'senderImagePath CONTAINS[c] "santa"'