diff --git a/src/main/java/dev/openfeature/sdk/EventDetails.java b/src/main/java/dev/openfeature/sdk/EventDetails.java
index d4ecac93..02b1964d 100644
--- a/src/main/java/dev/openfeature/sdk/EventDetails.java
+++ b/src/main/java/dev/openfeature/sdk/EventDetails.java
@@ -1,6 +1,5 @@
 package dev.openfeature.sdk;
 
-import edu.umd.cs.findbugs.annotations.Nullable;
 import lombok.Data;
 import lombok.experimental.SuperBuilder;
 
@@ -19,8 +18,8 @@ public class EventDetails extends ProviderEventDetails {
 
     static EventDetails fromProviderEventDetails(
             ProviderEventDetails providerEventDetails,
-            @Nullable String providerName,
-            @Nullable String clientName) {
+            String providerName,
+            String clientName) {
         return EventDetails.builder()
                 .clientName(clientName)
                 .providerName(providerName)
diff --git a/src/main/java/dev/openfeature/sdk/EventSupport.java b/src/main/java/dev/openfeature/sdk/EventSupport.java
index 49156b1a..aa48b8b0 100644
--- a/src/main/java/dev/openfeature/sdk/EventSupport.java
+++ b/src/main/java/dev/openfeature/sdk/EventSupport.java
@@ -2,7 +2,6 @@ package dev.openfeature.sdk;
 
 import lombok.extern.slf4j.Slf4j;
 
-import javax.annotation.Nullable;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -41,7 +40,7 @@ class EventSupport {
      * @param event        the event type
      * @param eventDetails the event details
      */
-    public void runClientHandlers(@Nullable String clientName, ProviderEvent event, EventDetails eventDetails) {
+    public void runClientHandlers(String clientName, ProviderEvent event, EventDetails eventDetails) {
         clientName = Optional.ofNullable(clientName)
                 .orElse(defaultClientUuid);
 
@@ -74,7 +73,7 @@ class EventSupport {
      * @param event      the event type
      * @param handler    the handler function to run
      */
-    public void addClientHandler(@Nullable String clientName, ProviderEvent event, Consumer<EventDetails> handler) {
+    public void addClientHandler(String clientName, ProviderEvent event, Consumer<EventDetails> handler) {
         final String name = Optional.ofNullable(clientName)
                 .orElse(defaultClientUuid);
 
diff --git a/src/main/java/dev/openfeature/sdk/FlagEvaluationDetails.java b/src/main/java/dev/openfeature/sdk/FlagEvaluationDetails.java
index af48d877..4562ea1e 100644
--- a/src/main/java/dev/openfeature/sdk/FlagEvaluationDetails.java
+++ b/src/main/java/dev/openfeature/sdk/FlagEvaluationDetails.java
@@ -2,8 +2,6 @@ package dev.openfeature.sdk;
 
 import java.util.Optional;
 
-import javax.annotation.Nullable;
-
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -23,12 +21,9 @@ public class FlagEvaluationDetails<T> implements BaseEvaluation<T> {
 
     private String flagKey;
     private T value;
-    @Nullable
     private String variant;
-    @Nullable
     private String reason;
     private ErrorCode errorCode;
-    @Nullable
     private String errorMessage;
     @Builder.Default
     private ImmutableMetadata flagMetadata = ImmutableMetadata.builder().build();
diff --git a/src/main/java/dev/openfeature/sdk/OpenFeatureAPI.java b/src/main/java/dev/openfeature/sdk/OpenFeatureAPI.java
index 896d60a3..db28555a 100644
--- a/src/main/java/dev/openfeature/sdk/OpenFeatureAPI.java
+++ b/src/main/java/dev/openfeature/sdk/OpenFeatureAPI.java
@@ -7,8 +7,6 @@ import java.util.Optional;
 import java.util.Set;
 import java.util.function.Consumer;
 
-import javax.annotation.Nullable;
-
 import dev.openfeature.sdk.exceptions.OpenFeatureError;
 import dev.openfeature.sdk.internal.AutoCloseableLock;
 import dev.openfeature.sdk.internal.AutoCloseableReentrantReadWriteLock;
@@ -67,14 +65,14 @@ public class OpenFeatureAPI implements EventBus<OpenFeatureAPI> {
     /**
      * {@inheritDoc}
      */
-    public Client getClient(@Nullable String name) {
+    public Client getClient(String name) {
         return getClient(name, null);
     }
 
     /**
      * {@inheritDoc}
      */
-    public Client getClient(@Nullable String name, @Nullable String version) {
+    public Client getClient(String name, String version) {
         return new OpenFeatureClient(this,
                 name,
                 version);
diff --git a/src/main/java/dev/openfeature/sdk/ProviderEvaluation.java b/src/main/java/dev/openfeature/sdk/ProviderEvaluation.java
index c4720263..004f5cfd 100644
--- a/src/main/java/dev/openfeature/sdk/ProviderEvaluation.java
+++ b/src/main/java/dev/openfeature/sdk/ProviderEvaluation.java
@@ -1,7 +1,5 @@
 package dev.openfeature.sdk;
 
-import javax.annotation.Nullable;
-
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -18,10 +16,10 @@ import lombok.NoArgsConstructor;
 @AllArgsConstructor
 public class ProviderEvaluation<T> implements BaseEvaluation<T> {
     T value;
-    @Nullable String variant;
-    @Nullable private String reason;
+    String variant;
+    private String reason;
     ErrorCode errorCode;
-    @Nullable private String errorMessage;
+    private String errorMessage;
     @Builder.Default
     private ImmutableMetadata flagMetadata = ImmutableMetadata.builder().build();
 }
diff --git a/src/main/java/dev/openfeature/sdk/ProviderEventDetails.java b/src/main/java/dev/openfeature/sdk/ProviderEventDetails.java
index 149c92a7..d28da9e5 100644
--- a/src/main/java/dev/openfeature/sdk/ProviderEventDetails.java
+++ b/src/main/java/dev/openfeature/sdk/ProviderEventDetails.java
@@ -2,8 +2,6 @@ package dev.openfeature.sdk;
 
 import java.util.List;
 
-import javax.annotation.Nullable;
-
 import lombok.Data;
 import lombok.experimental.SuperBuilder;
 
@@ -12,7 +10,7 @@ import lombok.experimental.SuperBuilder;
  */
 @Data @SuperBuilder(toBuilder = true)
 public class ProviderEventDetails {
-    @Nullable private List<String> flagsChanged;
-    @Nullable private String message;
-    @Nullable private ImmutableMetadata eventMetadata;
+    private List<String> flagsChanged;
+    private String message;
+    private ImmutableMetadata eventMetadata;
 }
diff --git a/src/main/java/dev/openfeature/sdk/ProviderRepository.java b/src/main/java/dev/openfeature/sdk/ProviderRepository.java
index 8dee0a6f..1ebd9b4c 100644
--- a/src/main/java/dev/openfeature/sdk/ProviderRepository.java
+++ b/src/main/java/dev/openfeature/sdk/ProviderRepository.java
@@ -13,8 +13,6 @@ import java.util.function.Consumer;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-import javax.annotation.Nullable;
-
 import dev.openfeature.sdk.exceptions.GeneralError;
 import dev.openfeature.sdk.exceptions.OpenFeatureError;
 import lombok.extern.slf4j.Slf4j;
@@ -100,7 +98,7 @@ class ProviderRepository {
         prepareAndInitializeProvider(clientName, provider, afterSet, afterInit, afterShutdown, afterError, waitForInit);
     }
 
-    private void prepareAndInitializeProvider(@Nullable String clientName,
+    private void prepareAndInitializeProvider(String clientName,
               FeatureProvider newProvider,
               Consumer<FeatureProvider> afterSet,
               Consumer<FeatureProvider> afterInit,