host.updates

Wraps SwiftUI’s own layout pass. Aggregated into a rolling window, one reading per window tick while a host is on screen.


Delivery	stream, interval
Mechanism	swizzle
Requires	iOS 17+, basset 0.1.1+

Real output from basset request get, captured against a running app:

CAPTURED                  ELAPSED  INSTRUMENT

launch 13632765096152408638
2026-08-23T15:06:06.455Z  +0.0s    swiftui.host.updates(swiftUIHost)
├─ windowNanoseconds  1000038458
├─ passCount          8
├─ totalNanoseconds   484627
├─ peakNanoseconds    154959
└─ hostCount          1
2026-08-23T15:06:07.454Z  +1.0s    swiftui.host.updates(swiftUIHost)
├─ windowNanoseconds  999264834
├─ passCount          1095
├─ totalNanoseconds   130593679
├─ peakNanoseconds    2146792
└─ hostCount          1
2026-08-23T15:06:08.455Z  +2.0s    swiftui.host.updates(swiftUIHost)
├─ windowNanoseconds  1000900291
├─ passCount          1320
├─ totalNanoseconds   167798677
├─ peakNanoseconds    1638792
└─ hostCount          1

Getting Started

SDK

CLI

Instruments

Reference