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

# Apple SDK

> Learn how to use our client side Apple SDK.

The Apple SDK is published at [GitHub](https://github.com/prelude-so/apple-sdk).

<Info>
  If you find issues uploading your app to the Apple App Store regarding the PreludeCore.xcframework [please follow these steps.](#uploading-your-app-to-the-app-store)
</Info>

### Usage

The Apple SDK allows you to capture certain device signals that will be reported back to Prelude and perform silent verification of mobile devices.

It is provided as a regular Swift package that you can [import as a dependency directly into your iOS application](https://developer.apple.com/documentation/xcode/adding-package-dependencies-to-your-app).

#### Gathering Device Signals

Usage of the SDK to gather the signals is very simple, you just need to configure it with your SDK key and call a single dispatch function:

```objective-c theme={null}
let configuration = Configuration(sdkKey: "sdk_XXXXXXXXXXXX")
let prelude = Prelude(configuration)
let dispatchID = try? await prelude.dispatchSignals()
```

Once you get the dispatch ID you should report it back to your own back-end API to be forwarded in subsequent network calls.

There is no restriction on when to call this API, you just need to take this action before you need to report back the dispatch ID. The recommended way of integrating it is to call the `dispatchSignals` function before displaying the phone number verification screen in your application. This way you can ensure that the device signals are captured and the `dispatchID` can be sent to your back-end with the phone number. Your back-end will then perform the verification call to Prelude with the phone number and the dispatch identifier.

#### Silent Verification

The Silent Verification feature allows you to verify a phone number without requiring the user to manually enter a verification code.

It is available for certain carriers and requires a server-side service to handle the verification process. For this verification method to work properly, you must gather the device signals mentioned before and report the dispatch identifier to your backend (usually in your APIs verification endpoint).

Please refer to the [Silent Verification documentation](https://docs.prelude.so/verify/v2/documentation/silent-verification) for more information on how to implement this feature.

#### CocoaPods integration

We currently do not offer CocoaPods integration for the SDK, but creating one is a relatively straightforward process.
The steps to take are:

* Download the source code from this repository, for example to a directory like `prelude-apple-sdk/sdk`.
* Open the `Package.swift` file and copy the url for the Core sdk defined in the binary target (similar to `https://prelude-public.s3.amazonaws.com/sdk/releases/apple/core/X.X.X/PreludeCore-X.X.X.xcframework.zip`).
* Download the Core SDK from that url and unzip it to a subdirectory of the one above (for example `prelude-apple-sdk/sdk/core`). You should have a single subdirectory `PreludeCore.xcframework` under `prelude-apple-sdk/core`
* Remove the `Package.swift` file.
* Create a new `podspec` file in the root of the `prelude-apple-sdk` directory with the following content:

```ruby theme={null}
Pod::Spec.new do |s|
  s.name           = 'PreludeAppleSDK'
  s.version        = 'X.X.X' # Update this to the version of the SDK
  s.summary        = 'Prelude Apple SDK'
  s.license        = 'Apache-2.0'
  s.author         = 'Prelude <hello@prelude.so> (https://github.com/prelude-so)'
  s.homepage       = 'https://github.com/prelude-so/apple-sdk'
  s.platforms      = { :ios => '15.1' }
  s.swift_version  = '5.4'
  s.source         = { git: 'https://github.com/prelude-so/apple-sdk' }
  s.static_framework = true
  s.vendored_frameworks = 'sdk/core/PreludeCore.xcframework'
  s.pod_target_xcconfig = {
    'DEFINES_MODULE' => 'YES',
    'SWIFT_COMPILATION_MODE' => 'wholemodule'
  }
  s.source_files = "**/*.swift", "../sdk/**/*.swift"
end
```

The final directory structure should look like this:

<Tree>
  <Tree.Folder name="prelude-apple-sdk" defaultOpen>
    <Tree.Folder name="sdk" defaultOpen>
      <Tree.Folder name="core" defaultOpen>
        <Tree.File name="PreludeCore.xcframework" />
      </Tree.Folder>

      <Tree.Folder name="Sources" defaultOpen>
        <Tree.Folder name="Prelude" defaultOpen>
          <Tree.File name="..." />
        </Tree.Folder>
      </Tree.Folder>
    </Tree.Folder>

    <Tree.File name="PreludeAppleSDK.podspec" />
  </Tree.Folder>
</Tree>

Import this `.podspec` file into your project and run normally.

With these steps you should have a working version of the SDK in your project.

#### Uploading your app to the App Store

Depending on the mechanism that you use to upload your app to the App Store, you may find errors related to the `PreludeCore.xcframework` file.

If you encounter this error, try uploading the app again with the flag `--use-old-altool`:

```
xcrun altool --upload-app --type ios --file "path/to/your/app.ipa" --apiKey "YourAPIKey" --apiIssuer "YourIssuerID" --use-old-altool
```

If you use Fastlane to build your app, you may want to configure it instead in your lane similar to this:

```ruby theme={null}
before_all do
.....
    ENV["DELIVER_ALTOOL_ADDITIONAL_UPLOAD_PARAMETERS"] = "--use-old-altool"
....
end
```