---
title: "init(appExtensionBundle:)"
framework: webkit
role: symbol
role_heading: Initializer
path: "webkit/wkwebextension/init(appextensionbundle:)"
---

# init(appExtensionBundle:)

Creates a web extension initialized with a specified app extension bundle.

## Declaration

```swift
@MainActor @preconcurrency convenience init(appExtensionBundle: Bundle) async throws
```

## Parameters

- `appExtensionBundle`: The bundle to use for the new web extension.

## Discussion

Discussion The app extension bundle must contain a manifest.json file in its resources directory. If the manifest is invalid or missing, or the bundle is otherwise improperly configured, an error will be thrown. note: An error if the manifest is invalid or missing, or the bundle is otherwise improperly configured.