Axiom Metrickit Ref

If you're working with MetricKit in iOS development, this is your API reference for handling performance metrics and diagnostics from real user devices. It covers the essentials: setting up subscribers, parsing metric and diagnostic payloads, symbolicating crash data from MXCallStackTree, and decoding those cryptic background exit reasons like jetsam events and watchdog kills. The documentation is especially useful if you're integrating MetricKit alongside existing crash reporting tools and need to understand what data you're actually getting from Apple's aggregated daily reports. It's comprehensive enough to be your go-to when you're knee-deep in performance instrumentation and need to know exactly what properties are available on each payload type.