> ## Documentation Index
> Fetch the complete documentation index at: https://docs.basset.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# host.updates

> How often SwiftUI's hosting views lay out, and how long each pass takes

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

| | |
| - | - |
| [Delivery](/instruments/metadata) | stream, interval |
| Mechanism | swizzle |
| [Requires](/instruments/metadata) | 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
```


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