---
title: OSBundleUsageDescriptionKey
framework: systemextensions
role: symbol
role_heading: Global Variable
path: systemextensions/osbundleusagedescriptionkey
---

# OSBundleUsageDescriptionKey

A message that tells the user why the app is trying to install a driver extension bundle.

## Declaration

```swift
let OSBundleUsageDescriptionKey: String
```

## Discussion

Discussion This key is required for all DriverKit extensions and must be in the extension’s Info.plist file. Failure to include this key results in an error at activation time. For system extensions that are not DriverKit extensions, use NSSystemExtensionUsageDescriptionKey instead.

## See Also

### Usage descriptions

- [NSSystemExtensionUsageDescriptionKey](systemextensions/nssystemextensionusagedescriptionkey.md)