> ## 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.

# Introduction to the Frontend SDKs

> Learn how to use our Frontend SDKs

Our Frontend SDKs are available for Android, iOS, Web, React Native and Flutter. They enable you to:

1. Collect device signals to strengthen verification and reduce fraud.
2. Perform [silent verification](/verify/v2/documentation/silent-verification) to verify phone numbers without asking users to enter a code.

The Frontend SDKs currently can integrate with the [Verify](/verify/v2/documentation/introduction) and [Watch](/watch/v2/documentation/introduction) APIs.

<Info>
  **SDK keys are publishable, client-side keys — safe to expose.** Unlike your backend [API key](/verify/v2/documentation/quickstart), the SDK key is designed to be embedded in client applications. It is expected to be visible in your browser JavaScript bundle, page source, or mobile app binary, and it is safe to keep in front-end deployment config such as CI/CD pipelines and Helm values.
</Info>

<Note>
  **Use a separate SDK key for each platform.** When generating an SDK key in the dashboard, select the device platform (Android, Apple, Web, etc.) that matches your intended use case. Prelude enforces that scoped SDK keys can only be used by matching device platforms, which prevents cross-platform misuse and lets you rotate or revoke a single platform's key independently.
</Note>

## How device signal collection works

<Steps>
  <Step title="Capture device signals">
    The Frontend SDK collects device signals and dispatches them to Prelude.
  </Step>

  <Step title="Dispatch ID creation">
    Prelude generates a Dispatch ID from those signals and returns it to the SDK.
  </Step>

  <Step title="Dispatch ID usage">
    Forward the Dispatch ID to your backend and include it in requests to Prelude's [Verify](/verify/v2/documentation/introduction) or [Watch](/watch/v2/documentation/introduction) APIs.
  </Step>
</Steps>

## Learn more about each platform's SDK

<Columns>
  <Card title="Web SDK" href="/introduction/frontend-sdks/web" icon="globe">
    Learn how to integrate the Web SDK into your application.
  </Card>

  <Card title="Android SDK" href="/introduction/frontend-sdks/android" icon="android">
    Learn how to integrate the Android SDK into your application.
  </Card>

  <Card title="iOS SDK" href="/introduction/frontend-sdks/apple" icon="apple">
    Learn how to integrate the iOS SDK into your application.
  </Card>

  <Card title="React Native SDK" href="/introduction/frontend-sdks/react-native" icon="react">
    Learn how to integrate the React Native SDK into your application.
  </Card>

  <Card title="Flutter SDK" href="/introduction/frontend-sdks/flutter" icon="flutter">
    Learn how to integrate the Flutter SDK into your application.
  </Card>
</Columns>