---
title: volumeAvailableCapacityForOpportunisticUsageKey
framework: foundation
role: symbol
role_heading: Type Property
path: foundation/urlresourcekey/volumeavailablecapacityforopportunisticusagekey
---

# volumeAvailableCapacityForOpportunisticUsageKey

Key for the volume’s available capacity in bytes for storing nonessential resources (read-only).

## Declaration

```swift
static let volumeAvailableCapacityForOpportunisticUsageKey: URLResourceKey
```

## Mentioned in

Checking Volume Storage Capacity

## Discussion

Discussion important: This API has the potential of being misused to access device signals to try to identify the device or user, also known as fingerprinting. Regardless of whether a user gives your app permission to track, fingerprinting is not allowed. When you use this API in your app or third-party SDK (an SDK not provided by Apple), declare your usage and the reason for using the API in your app or third-party SDK’s PrivacyInfo.xcprivacy file. For more information, including the list of valid reasons for using the API, see Describing use of required reason API.

## See Also

### Volume capacity keys

- [Checking Volume Storage Capacity](foundation/checking-volume-storage-capacity.md)
- [volumeAvailableCapacityKey](foundation/urlresourcekey/volumeavailablecapacitykey.md)
- [volumeAvailableCapacityForImportantUsageKey](foundation/urlresourcekey/volumeavailablecapacityforimportantusagekey.md)
- [volumeTotalCapacityKey](foundation/urlresourcekey/volumetotalcapacitykey.md)