macOS Logs

macOS Unified Logging and legacy system logs: subsystem debug, kernel alerts and application crash reports.

Global Fields (4)

FieldType
ngs.id
Unique identifier for the log entry.
string
ngs.createdAt
Timestamp when the event was created locally.
pdate
ngs.indexedAt
Timestamp when the log was indexed into the SIEM.
pdate
ngs.source
Origin or source system of the log.
string

Reference-Specific Fields (23)

FieldType
maclog.traceID
Unique numeric identifier for this trace event.
plong
maclog.eventMessage
Human-readable log message describing the event.
text_general
maclog.eventType
Type or classification of the logged event.
text_general
maclog.activityIdentifier
Numeric identifier for the activity context.
plong
maclog.subsystem
Subsystem or module that generated the log.
text_general
maclog.category
Log category grouping similar messages.
text_general
maclog.threadID
Identifier of the thread where the event occurred.
plong
maclog.userID
Numeric user identifier associated with the event.
plong
maclog.senderImageUUID
UUID of the code image that sent the message.
string
maclog.backtrace.frames.imageOffset
List of offsets within each image for backtrace frames.
plong []
maclog.backtrace.frames.imageUUID
List of UUIDs of images referenced in backtrace frames.
string []
maclog.bootUUID
UUID of the system boot session.
string
maclog.processImagePath
Filesystem path to the process's executable image.
text_general
maclog.timestamp
Date and time when the log entry was created.
pdate
maclog.senderImagePath
Filesystem path to the sender code image.
text_general
maclog.machTimestamp
Kernel Mach timestamp for the event.
plong
maclog.messageType
Format or type of the log message.
text_general
maclog.processImageUUID
UUID of the process executable image.
string
maclog.processID
Process identifier (PID) generating the log.
plong
maclog.senderProgramCounter
Program counter value at the point of logging.
plong
maclog.parentActivityIdentifier
Identifier of the parent activity context.
plong
maclog.timezoneName
Name of the local timezone when logged.
text_general
maclog.formatString
Original format string used to generate the message.
text_general

Sample Log Event

Below is a representative JSON log entry showing key fields as they’re emitted by the system. Depending on the context of the event, some fields may be omitted if they’re not applicable.