Lite SDK (Payment Android)

The Yuno Lite SDK for Android provides a pre-built UI solution focused on card payment processing. This SDK offers a streamlined integration process with essential payment functionality, making it ideal for merchants who:

• Need a quick implementation with minimal customization requirements
• Want to focus primarily on card payment processing
• Prefer a ready-to-use UI that handles the payment flow

The Lite SDK includes core features like:

• Pre-built payment UI components
• Card payment processing
• Basic payment status handling
• Essential error management

For merchants requiring more advanced features like multiple payment methods, custom UI, or advanced fraud prevention, consider using our Full SDK instead.

Requirements

Before starting the Yuno Android SDK integration, make sure your project meets the technical requirements. In addition, ensure the following prerequisites are in place:

• You must have an active Yuno account.
• To perform the integration, you'll need your Yuno API credentials (account_id, public-api-key, and private-secret-key), which you can obtain from the Developers credentials section of the Yuno dashboard. These credentials are required to authenticate requests to the Yuno API. The API is used to:
  • Create a customer, which is required before initiating payments
  • Create a checkout_session, which initializes the payment flow
  • Create the payment associated with the session

Step 1: Create a customer

Before initiating payments, you need to create a customer using the Create customer endpoint. This step is required to:

• Identify the person making the payment
• Enable saved card functionality (if enabled)
• Track payment history

The customer ID returned from this endpoint will be used when creating the checkout_session.

Step 2: Create a checkout session

To initialize the payment flow, create a new checkout_session using the Create checkout session endpoint. Make sure to:

• Include the customer ID obtained from the previous step
• Store the returned checkout_session ID for use in Step 5 of the integration
• The checkout_session is unique for each payment attempt and cannot be reused

Step 3: Include the library in your project

Ensure the Yuno SDK file is included in your project through Gradle. Then, add the repository source using the following code line:

maven { url "https://yunopayments.jfrog.io/artifactory/snapshots-libs-release" }

After, include the code below in the file build.gradle to add the Yuno SDK dependency to the application.

dependencies {
    implementation 'com.yuno.payments:android-sdk:{last_version}'
}

Permissions

Yuno SDK includes, by default, the INTERNET permission, which is required to make network requests.

<uses-permission android:name="android.permission.INTERNET" />

Step 4: Initialize SDK with the public key

To initialize the SDK:

1. Get your public API keys from the Yuno dashboard
2. Create a custom application class if you don't have one
3. Initialize the SDK by calling Yuno.initialize() in your application's onCreate() method, passing your API key and configuration:

class CustomApplication : Application() {
  override fun onCreate() {
    super.onCreate()
    Yuno.initialize(
      this,
      "your api key",
      config: YunoConfig, // This is a data class to use custom configs in the SDK.
    )
  }
}

Use the data class YunoConfig to customize the SDK's behavior. You can include this configuration when calling Yuno.initialize(). The available options are:

data class YunoConfig(
    val cardFlow: CardFormType = CardFormType.ONE_STEP, // Optional: Defines the card form flow type. ONE_STEP shows a single screen for card details, TWO_STEP splits it across multiple screens.
    val saveCardEnabled: Boolean = false, // Determines whether to display the "Save card" checkbox on card flows.
    val keepLoader: Boolean = false, // If true, keeps the Yuno loading screen visible until payment creation and continuation. Requires an additional step described later.
    val cardFormDeployed: Boolean = false, // Full SDK only: If true, displays the card form within the payment methods list. If false, shows the card form on a separate screen.
    val language: YunoLanguage? = null, // Sets the SDK language. If null or not provided, defaults to the device language.
    val styles: YunoStyles? = null // Enables SDK-wide UI customization.
)

The following table includes descriptions for each customization available.

You also need to update your manifest to use your application:

<application android:name=".CustomApplication"></application>

Step 5: Start the checkout process

To initiate a new payment process with the Lite SDK, call the startCheckout method in the onCreate() function of the activity that integrates the SDK:

startCheckout(
  checkoutSession: "checkout_session",
  // Replace with your target country's ISO code (e.g., "US" for USA, "FR" for France). The complete list of country_codes is available on https://docs.y.uno/docs/country-coverage-yuno-sdk.
  countryCode: "US",
  callbackPaymentState: ((String?) -> Unit)?,
  merchantSessionId: String? = null //Optional - Default null 
)

Below is a description of the required parameters to start the checkout.

Callback Payment State

The callbackPaymentState parameter is a function that returns the current payment process. Sending this function is not mandatory if you do not need the result. The possible states are:

const val PAYMENT_STATE_SUCCEEDED = "SUCCEEDED"
const val PAYMENT_STATE_FAIL = "FAIL"
const val PAYMENT_STATE_PROCESSING = "PROCESSING"
const val PAYMENT_STATE_REJECT = "REJECT"
const val PAYMENT_STATE_INTERNAL_ERROR = "INTERNAL_ERROR"
const val PAYMENT_STATE_STATE_CANCELED_BY_USER = "CANCELED"

The following table provide additional information about the possible states:

Step 6: Initiate the payment process

To start a payment process, you have to call the method startPaymentLite.

startPaymentLite(
    paymentSelected: PaymentSelected,
    callbackOTT:(String?) -> Unit, //Optional - Default null,
    callBackTokenWithInformation:(OneTimeTokenModel?) -> Unit, //Optional - Default null
    showPaymentStatus: Boolean, //Optional - Default true
) 

Below is a description of the required parameters to start the payment.

You need to send an additional parameter, which is the vaulted token and/or the payment type that the user selected to make the payment.

PaymentSelected(
  vaultedToken : String "payment_vaulted_token",
  paymentMethodType : String "payment_type",
)

Step 7: Get the OTT (one-time token)

The one-time token is a unique identifier that represents a payment session. This token is required to create a payment.

Callback one-time token

The one-time token callback returns the following parameters:

Step 8: Create the payment

After completing the previous steps, create a payment by calling the Create Payment endpoint from your backend. This endpoint requires:

• The one-time token obtained in Step 7
• The checkout_session obtained in Step 2

For payment methods that require additional customer actions (such as 3DS authentication challenges) or asynchronous processing (like bank transfers), you'll need to integrate the SDK's continuePayment method after creating the payment. The Create Payment API response includes a sdk_action_required field that indicates whether this step is needed:

• If TRUE: Call yuno.continuePayment() to display additional screens for customer actions (e.g., 3DS authentication, bank redirect pages)
• If FALSE: Skip this step as no additional customer interaction is required

Here's how to implement the payment continuation flow:

continuePayment(
    showPaymentStatus: Boolean = true, // Optional – Default true
    checkoutSession: String? = null,   // Optional – Default null
    countryCode: String? = null,       // Optional – Default null
    callbackPaymentState: ((String?) -> Unit)? = null // Optional – Default null
)

To show your payment status screens, you should send FALSE in the showPaymentStatus parameter. Then, get the payment state by callback.

Complementary features

Yuno Android SDK provides additional services and configurations you can use to improve customers' experience. Use the SDK customization to change the SDK appearance to match your brand or to configure the loader.

styles

With the styles customization option, you can define global visual styles like through a YunoStyles object. It lets you apply consistent branding across the SDK by customizing button appearance and typography.

data class YunoStyles(
    val buttonStyles: YunoButtonStyles? = null,
    val fontFamily: FontFamily? = null
)

The YunoButtonStyles object lets you define specific settings for button appearance:

data class YunoButtonStyles(
    val backgroundColor: Color? = null,
    val contentColor: Color? = null,
    val cornerRadius: Dp? = null,
    val elevation: Dp? = null,
    val padding: Dp? = null,
    val fontFamily: FontFamily? = null,
    val fontSize: TextUnit? = null,
    val fontStyle: FontStyle? = null
)

To use the styles customization option, you have to use the YunoConfig data class, described in Step 2.

Loader

The Loader enables you to control the use of the loader component.

Save card for future payments

In addition, you can display a checkbox to save or enroll cards using cardSaveEnable: true. Below, you can find examples of the checkbox for both card form renders:

Render options

You can choose between two card form render options. The following screenshots demonstrate the difference between cardFormType ONE_STEP and STEP_BY_STEP:

SDK customization

You can change the SDK appearance to match your brand. For more information, access the SDK customization page.