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# FSKit updates

Learn about important changes to FSKit.

## Overview

Browse notable changes in <doc://com.apple.documentation/documentation/FSKit>.

## June 2026

- Update your <doc://com.apple.documentation/documentation/FSKit/FSVolume> implementations to adopt <doc://com.apple.documentation/documentation/FSKit/FSVolume/Handler> and the related “handler” protocols, which replace the now-deprecated <doc://com.apple.documentation/documentation/FSKit/FSVolume/Operations> and other “operations” protocols. The “Handler” protocols provide richer <doc://com.apple.documentation/documentation/FSKit/FSVolumeHandlerResult> subtypes to pass back to the framework after each call completes. Some calls also provide an <doc://com.apple.documentation/documentation/FSKit/FSContext> parameter which contains user and group identifiers. You can use these to restrict access to your filesystem to known callers.
- Improve performance with kernel data caching, by conforming to the <doc://com.apple.documentation/documentation/FSKit/FSVolume/DataCacheHandler> protocol.

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