diff --git a/README.md b/README.md
index 65cb5d0..b4a845d 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,8 @@
 # Payment Engine
 
 Android library which combines different payments protocols into single interface solution. So far supported payments are:
-* **ZVT** 
+* **ZVT** - Zero Reactive Voltage Transmission is an german abbreviation and stands for Payment Terminal
+* **OPI** - The Open Payment Initiative, or O.P.I. for short
 # How to setup
 
 **Step 1.** Add the JitPack repository to your `settings.gradle` file:
@@ -14,7 +15,7 @@ dependencyResolutionManagement {
     repositories {
         ...
         mavenCentral()
-		maven { url 'https://jitpack.io' }
+        maven { url 'https://jitpack.io' }
     }
 }
 ```
@@ -58,24 +59,24 @@ override fun onCreate(savedInstanceState: Bundle?) {
 
 ### 2. Usage of PaymentEngine
 
-`PaymentEngine.kt` is per Activity singlton helper class which tries to simplify the process of implementation and it gives you access to all library available actions (managers).
+`PaymentEngine.kt` is singlton helper class which tries to simplify the process of implementation and it gives you access to all library available actions (managers).
 
 * `PaymentManager` is used to start of a card payment transaction
 * `RefundManager` is used to start of a partial card payment refund
 * `ReversalManager` is used to start of a card payment reversal
 * `ReconciliationManager` is used to start of a terminal reconciliation
 
-It also gives you more flexibility setting up terminal configuration, observing result through SharedFlow and triggering actions with multiple methods. 
+It also gives you more flexibility setting up terminal configuration, observing result through singleton Flow and triggering actions with multiple methods. 
 
 ```kotlin
 private val paymentEngine: PaymentEngine by lazy {
-    PaymentEngine.getInstance(this)
+    PaymentEngine.getInstance()
 }
 
 override fun onCreate(savedInstanceState: Bundle?) {
     // ...
 
-    val paymentManager = paymentEngine.newPaymentManager().build(lifecycle)
+    val paymentManager = paymentEngine.newPaymentManager(this)
 
     ...
 
diff --git a/payment-engine/build.gradle.kts b/payment-engine/build.gradle.kts
index ac04607..b139479 100644
--- a/payment-engine/build.gradle.kts
+++ b/payment-engine/build.gradle.kts
@@ -92,7 +92,7 @@ afterEvaluate {
             create<MavenPublication>("payment-engine") {
                 groupId = "de.tillhub.paymentengine"
                 artifactId = "payment-engine"
-                version = "1.3.4"
+                version = "2.0.1"
 
                 from(components.getByName("release"))
             }
diff --git a/payment-engine/proguard-rules.pro b/payment-engine/proguard-rules.pro
index 16dd60c..7856ec2 100644
--- a/payment-engine/proguard-rules.pro
+++ b/payment-engine/proguard-rules.pro
@@ -52,6 +52,42 @@
 -keep class de.tillhub.paymentengine.data.TransactionData { *; }
 -keep class de.tillhub.paymentengine.data.TransactionResultCode { *; }
 
+# Communication classes
+-keep class de.tillhub.paymentengine.opi.data.CardServiceRequest { *; }
+-keep class de.tillhub.paymentengine.opi.data.PosData { *; }
+-keep class de.tillhub.paymentengine.opi.data.TotalAmount { *; }
+-keep class de.tillhub.paymentengine.opi.data.OriginalTransaction { *; }
+-keep class de.tillhub.paymentengine.opi.data.ServiceRequestType { *; }
+-keep class de.tillhub.paymentengine.opi.data.CardServiceResponse { *; }
+-keep class de.tillhub.paymentengine.opi.data.Terminal { *; }
+-keep class de.tillhub.paymentengine.opi.data.Tender { *; }
+-keep class de.tillhub.paymentengine.opi.data.CardDetails { *; }
+-keep class de.tillhub.paymentengine.opi.data.CardValue { *; }
+-keep class de.tillhub.paymentengine.opi.data.PrivateData { *; }
+-keep class de.tillhub.paymentengine.opi.data.Authorisation { *; }
+-keep class de.tillhub.paymentengine.opi.data.ValueElement { *; }
+-keep class de.tillhub.paymentengine.opi.data.OverallResult { *; }
+-keep class de.tillhub.paymentengine.opi.data.DeviceRequest { *; }
+-keep class de.tillhub.paymentengine.opi.data.Output { *; }
+-keep class de.tillhub.paymentengine.opi.data.TextLine { *; }
+-keep class de.tillhub.paymentengine.opi.data.DeviceType { *; }
+-keep class de.tillhub.paymentengine.opi.data.DeviceRequestType { *; }
+-keep class de.tillhub.paymentengine.opi.data.DeviceResponse { *; }
+-keep class de.tillhub.paymentengine.opi.data.ServiceRequest { *; }
+-keep class de.tillhub.paymentengine.opi.data.ServiceResponse { *; }
+-keep class de.tillhub.paymentengine.opi.data.Reconciliation { *; }
+
+-keep public class org.simpleframework.**{ *; }
+-keep class org.simpleframework.xml.**{ *; }
+-keep class org.simpleframework.xml.core.**{ *; }
+-keep class org.simpleframework.xml.util.**{ *; }
+-keepattributes *Annotation*
+-keepattributes Signature
+
+-keepclasseswithmembers class * {
+    public <init>(android.content.Context, android.util.AttributeSet, int);
+}
+
 # Breaking changes with AGP 8.0
 # R8 upgrade documentation
 -dontwarn java.lang.invoke.StringConcatFactory
\ No newline at end of file