Link Android SDK

The Plaid Link SDK is a quick and secure way to link bank accounts to Plaid in your Android app. Link is a drop-in module that handles connecting a financial institution to your app (credential validation, multi-factor authentication, error handling, etc), without passing sensitive personal information to your server.

To get started with Plaid Link for Android, clone the GitHub repository and try out the example application, which provides a reference implementation in both Java and Kotlin. Youʼll want to sign up for free API keys through the Plaid Developer Dashboard to get started.

Before writing code using the SDK, you must first perform some setup steps to register your app with Plaid and configure your project.

To register your Android app ID:

1. Sign in to the Plaid Dashboard and go to the Team Settings -> API page.
2. Next to Allowed Android Package Names click Configure then Add New Android Package Name.
3. Enter your package name, for example com.plaid.example.
4. Click Save Changes.

Your Android app is now set up and ready to start integrating with the Plaid SDK.

In your root-level (project-level) Gradle file (build.gradle), add rules to include the Android Gradle plugin. Check that you have Google's Maven repository as well.

buildscript {
    repositories {
        // Check that you have the following line (if not, add it):
        google()  // Google's Maven repository
        mavenCentral() // Include to import Plaid Link Android SDK
    }
    dependencies {
        // ...
    }
}

In your module (app-level) Gradle file (usually app/build.gradle), add a line to the bottom of the file. The latest version of the PlaidLink SDK is and can be found on Maven Central.

android {
  defaultConfig {
    minSdkVersion 21 // or greater
  }
  // Enable Java 8 support for Link to work
  compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
  }
}
dependencies {
  // ...
  implementation 'com.plaid.link:sdk-core:<insert latest version>'
}

Before you can open Link, you need to first create a link_token by calling /link/token/create from your backend. This call should never happen directly from the mobile client, as it risks exposing your API secret. The /link/token/create call must include the android_package_name parameter, which should match the applicationId from your app-level build.gradle file. You can learn more about applicationId in Google's Android developer documentation.

const request: LinkTokenCreateRequest = {
  user: {
    client_user_id: 'user-id',
  },
  client_name: 'Plaid Test App',
  products: ['auth', 'transactions'],
  country_codes: ['GB'],
  language: 'en',
  webhook: 'https://sample-web-hook.com',
  android_package_name: 'com.plaid.example'
  },
};
try {
  const response = await plaidClient.linkTokenCreate(request);
  const linkToken = response.data.link_token;
} catch (error) {
  // handle error
}

Each time you open Link, you will need to get a new link_token from your server and create a new LinkTokenConfiguration object with it.

val linkTokenConfiguration = linkTokenConfiguration {
  token = "LINK_TOKEN_FROM_SERVER"
}

The Link SDK runs as a separate Activity within your app. In order to return the result to your app, it supports both the standard startActivityForResult and onActivityResult and the ActivityResultContract result APIs.

@OptIn(PlaidActivityResultContract::class)
private val linkAccountToPlaid =
registerForActivityResult(OpenPlaidLink()) {
  when (it) {
    is LinkSuccess -> /* handle LinkSuccess */
    is LinkExit -> /* handle LinkExit */
  }
}

linkAccountToPlaid.launch(linkTokenConfiguration)

At this point, Link will open, and will trigger the onSuccess callback if the user successfully completes the Link flow.

private val linkResultHandler = LinkResultHandler(
  // ...
  onSuccess = { it: LinkSuccess ->
    // Send public_token to your server, exchange for access_token
    val publicToken = it.publicToken
    val metadata = it.metadata
    metadata.accounts.forEach { account ->
      val accountId = account.id
      val accountName = account.name
      val accountMask = account.mask
      val accountSubType = account.subtype
    }
    val institutionId = metadata.institution?.id
    val institutionName = metadata.institution?.name
  }
)

private val linkResultHandler = LinkResultHandler(
  // ...
  onExit = {
    val error = it.error
    error?.let { err ->
      val errorCode = err.errorCode
      val errorMessage = err.errorMessage
      val displayMessage = err.displayMessage
    }
    val metadata = it.metadata
    val institutionId = metadata.institution?.id
    val institutionName = metadata.institution?.name
    val linkSessionId = metadata.linkSessionId;
    val requestId = metadata.requestId;
  }
)

Plaid.setLinkEventListener { event -> Log.i("Event", event.toString()) }

If you run into problems integrating with Plaid Link on Android, see Troubleshooting the Plaid Link Android SDK.

Once you've gotten Link working, see Link best practices for recommendations on further improving the Link flow.