Headless SDK (Enrollment Android)

Orientation: Choosing Your Integration Flow, before you begin, please review the Official Integration Flow.

Standard Flow (Full Checkout): Recommended for most merchants. Yuno handles the UI, security, and automatic updates for payment methods.
Custom Flow (This SDK): Use this only if you require full control over the UX. Note: You will be responsible for manually handling payment statuses, 3DS transitions, and fraud routing data collection.

This page provides a guide to the Yuno Headless SDK for Android enrollment. The Yuno Headless SDK for Android provides a flexible, UI-free solution for enrolling payment methods and tokenizing cards. This SDK offers complete control over the payment method enrollment process, making it ideal for merchants who:

Need full control over the UI and user experience
Want to implement custom enrollment flows
Require advanced integration capabilities

The Headless SDK includes core features like:

Card tokenization
Secure payment method enrollment
Direct API access
Custom error handling

For merchants requiring a pre-built UI solution or simpler integration, consider using our other SDK implementations:

Requirements

Before starting the Yuno Android SDK integration, ensure your project meets the technical requirements:

Minimum SDK Version: minSdkVersion 21 or above
Java: Java 8 enabled
AndroidX: Use AndroidX instead of older support libraries
Android Gradle Plugin: 4.0.0 or above
ProGuard: 6.2.2 or above
Kotlin Gradle Plugin: 1.4.0 or above
ELF Page Size Support: Compliant with Google’s 16 KB ELF page alignment requirements (Android 15 / ARMv9 ready)

ProGuard / R8 Configuration

If your project has minifyEnabled = true, add these rules to your proguard-rules.pro file to ensure the SDK works correctly, especially with AGP 8.x+ R8 full mode.

Official Yuno ProGuard / R8 rules

# Preserve generic type signatures and annotations
-keepattributes Signature
-keepattributes *Annotation*

# Yuno SDK
-keep class com.yuno.** { *; }
-dontwarn com.yuno.**

# Gson — R8 full mode compatibility
-keep class com.google.gson.** { *; }
-keep,allowobfuscation,allowshrinking,allowoptimization class * extends com.google.gson.reflect.TypeToken
-dontwarn com.google.gson.**

# Retrofit — R8 full mode compatibility
-keep,allowobfuscation,allowshrinking interface retrofit2.Call
-keep,allowobfuscation,allowshrinking class retrofit2.Response
-keep,allowobfuscation,allowshrinking class kotlin.coroutines.Continuation
-dontwarn retrofit2.**

# OkHttp + Okio — Suppress warnings
-dontwarn okhttp3.**
-dontwarn okio.**

Why are these rules necessary?

AGP 8.x+ enables R8 full mode by default, which aggressively strips generic type signatures. Without -keepattributes Signature, Gson’s TypeToken<T> can fail at runtime with java.lang.Class cannot be cast to java.lang.reflect.ParameterizedType.

SDK Version InformationVerify the current SDK version by accessing the Release notes or visiting the Yuno Android SDK repository.

Step 1: Create a customer

Create a customer using the Create Customer endpoint before enrolling payment methods.

Step 2: Create a customer session

Create a new customer_session using the Create Customer Session endpoint:

Include the customer ID in the request
Store the returned customer_session ID
Generate a new customer_session for each payment method enrollment.

Step 3: Add the SDK to your project

Add the repository source:

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

Add the SDK dependency:

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

Internet Permission RequiredThe Yuno SDK automatically includes the INTERNET permission, necessary for network requests. Ensure your AndroidManifest.xml contains:<uses-permission android:name="android.permission.INTERNET" />

Step 4: Initialize Headless SDK with the public key

Retrieve your public API keys from the Yuno dashboard. If you haven’t implemented a custom application, create one. In the onCreate() method of your application class, call the initialize function (Yuno.initialize):

class CustomApplication : Application() {
  override fun onCreate() {
    super.onCreate()
    Yuno.initialize(
      this,
      PUBLIC_API_KEY,
      config: YunoConfig,
    )
  }
}

Step 5: Create an enrollment payment method object

Create an enrollment payment method object using the Enroll Payment Method endpoint to set up the Headless SDK integration for enrollment. When creating this object, specify which payment method type your customer can enroll in. Currently, the Headless SDK only supports the CARD payment method type.

Card VerificationTo verify cards (zero value authorization) before enrollment, include the verify object when creating the payment method object for the customer session.

Step 6: Start the enrollment process

Use the apiClientEnroll function to start the enrollment process. This function requires configuration parameters that define how the enrollment will be processed. The following table describes the required parameters:

Parameter	Description
`country_code`	This parameter determines the country for which the payment process is being configured. The complete list of supported countries and their `country_code` is available on the Country coverage page.
`customer_session`	Refers to the current enrollment’s customer session received as a response to the Create Customer Session endpoint. Example: `438413b7-4921-41e4-b8f3-28a5a0141638`

The following code block shows an example of the parameter configuration:

override fun onCreate(savedInstanceState: Bundle?) {
	val apiClientEnroll = Yuno.apiClientEnroll(
  	country_code = "CO",
    customer_session = "eec6578e-ac2f-40a0-8065-25b5957f6dd3",
    context = this 
  )
 }

Step 7: Generate a vaulted token

After collecting all required customer information, create a vaulted_token using the apiClientEnroll.continueEnrollment function. Since this is an asynchronous function, use a try/catch block to handle any errors that may occur. The following example shows how to create a vaulted_token:

apiClientEnroll.continueEnrollment( 
 collectedData = EnrollmentCollectedData(
    customerSession = "customer_session",
    paymentMethod = EnrollmentMethod(
           type = "CARD",
           card = CardData(
               save = true,
               detail = Detail(
                   expirationMonth = 11,
                   expirationYear = 55,
                   number = "4111111111111111",
                   securityCode = "123",
                   holderName = "Firstname Lastname",
                   type = CardType.DEBIT
               ),
           customer = Customer(
               id = "id",
               merchantCustomerId = "merchant_customer_id",
               firstName = "firstName",
               email = "email@email.com",
               country = "CO",
               document = Document(
                   documentType = "PAS",
                   documentNumber = "PAS12312"
               ),
             phone = Phone(
                   number = "321123321123",
                   countryCode = "57"
               )
            )
      )
   ),
  context = this
 )

The apiClientEnroll.continueEnrollment function returns an Observable type that extends LiveData. You can observe the response as a standard LiveData with type SingleLiveEvent<Map<String, Any?>>. This LiveData emits only once and returns a Map containing the complete response. Below is an example response from calling apiClientEnroll.continueEnrollment:

{
  "vaulted_token": "9104911d-5df9-429e-8488-ad41abea1a4b",
  "status": "SUCCEEDED",
  "customer": {
    "session": "eec6578e-ac2f-40a0-8065-25b5957f6dd3"
  }
}

The following code block shows an example of observing the response:

apiClientPayment.continueEnrollment(data, context).observe(context) { response ->
   val status = response["status"] as String?
   val vauldtedtoken = response["vaulted_token"] as String?
}

Enrollment flow states

The apiClientEnroll.continueEnrollment function returns a response that includes a status field indicating the current state of the enrollment process. The following are the possible states returned:

const val ENROLLMENT_STATE_SUCCEEDED = "SUCCEEDED"
const val ENROLLMENT_STATE_FAIL = "FAIL"
const val ENROLLMENT_STATE_PROCESSING = "PROCESSING"
const val ENROLLMENT_STATE_REJECT = "REJECT"
const val ENROLLMENT_STATE_INTERNAL_ERROR = "INTERNAL_ERROR"
const val ENROLLMENT_STATE_CANCELED_BY_USER = "CANCELED"

The following table provides additional information about the possible states:

State	Description	Additional action required
`SUCCEEDED`	The enrollment process was successfully completed without any errors.	No.
`FAIL`	The enrollment attempt failed due to errors such as data validation issues, server connection failures, or technical problems.	Yes. Investigate the cause of failure (validation, network, server) and take corrective measures.
`PROCESSING`	The enrollment is currently in progress, awaiting approval or verification.	No.
`REJECT`	The enrollment was rejected due to reasons such as missing requirements or detected inconsistencies.	Yes. Inform the user of the rejection, provide the reason if possible, and suggest next steps.
`INTERNAL_ERROR`	An unexpected internal error occurred within the system handling the enrollment process.	Yes. Requires technical intervention to review the system, fix internal issues, and retry or inform the user.
`CANCELED`	The user voluntarily canceled the enrollment process or exited before completion.	No.

Webhook Status TrackingConsider using the enrollment status received via Webhooks. Yuno recommends always using this status to base and make business decisions on your platform.

Error handling

Handle errors returned by the SDK in your app (e.g. failed payments, validation errors). For HTTP status and response codes, see Status and response codes in the API reference.

Overview

Seamless SDK

Lite SDK

Headless SDK

Card Enrollment

Additional Features

Resources

Additional Platforms

External Native Modules

Requirements

ProGuard / R8 Configuration

Why are these rules necessary?

Step 1: Create a customer

Step 2: Create a customer session

Step 3: Add the SDK to your project

Step 4: Initialize Headless SDK with the public key

Step 5: Create an enrollment payment method object

Step 6: Start the enrollment process

Step 7: Generate a vaulted token

Enrollment flow states

Error handling

​Requirements

​ProGuard / R8 Configuration

​Why are these rules necessary?

​Step 1: Create a customer

​Step 2: Create a customer session

​Step 3: Add the SDK to your project

​Step 4: Initialize Headless SDK with the public key

​Step 5: Create an enrollment payment method object

​Step 6: Start the enrollment process

​Step 7: Generate a vaulted token

​Enrollment flow states

​Error handling

Requirements

ProGuard / R8 Configuration

Why are these rules necessary?

Step 1: Create a customer

Step 2: Create a customer session

Step 3: Add the SDK to your project

Step 4: Initialize Headless SDK with the public key

Step 5: Create an enrollment payment method object

Step 6: Start the enrollment process

Step 7: Generate a vaulted token

Enrollment flow states

Error handling