diff --git a/build.gradle.kts b/build.gradle.kts
index 8f9ccc5..6020b18 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -66,12 +66,10 @@ kotlin {
   jvm {
     // set up according to https://jakewharton.com/gradle-toolchains-are-rarely-a-good-idea/
     compilerOptions {
-      apiVersion = kotlinTarget
-      languageVersion = kotlinTarget
       jvmTarget = JvmTarget.fromTarget(javaTarget)
       freeCompilerArgs.add("-Xjdk-release=$javaTarget")
-      progressiveMode = true
     }
+    withJava()
   }
 
   if (!isJvmOnlyBuild) {
@@ -356,4 +354,9 @@ if (isReleaseBuild) {
     }
   }
 
-}
\ No newline at end of file
+}
+
+tasks.withType(JavaCompile::class.java) {
+  targetCompatibility = javaTarget
+  sourceCompatibility = javaTarget
+}
diff --git a/src/jvmMain/kotlin/JavaAnthropic.kt b/src/jvmMain/kotlin/JavaAnthropic.kt
new file mode 100644
index 0000000..6e4a711
--- /dev/null
+++ b/src/jvmMain/kotlin/JavaAnthropic.kt
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2024 Kazimierz Pogoda / Xemantic
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.xemantic.ai.anthropic
+
+import com.xemantic.ai.anthropic.message.MessageRequest
+import com.xemantic.ai.anthropic.message.MessageResponse
+import kotlinx.coroutines.runBlocking
+import java.util.function.Consumer
+
+// a very early version of Java only SDK, adapting Kotlin idioms and coroutines
+// it might change a lot in the future
+
+class JavaAnthropic private constructor(
+  private val anthropic: Anthropic
+) {
+
+  companion object {
+
+    @JvmStatic
+    fun create(
+      configurer: Consumer<Anthropic.Config>
+    ): JavaAnthropic = JavaAnthropic(Anthropic { configurer.accept(this) })
+
+  }
+
+
+  inner class Messages {
+
+    fun createBlocking(
+      builder: Consumer<MessageRequest.Builder>
+    ): MessageResponse = runBlocking {
+      anthropic.messages.create {
+        builder.accept(this)
+      }
+    }
+
+  }
+
+  @JvmField
+  val messages = Messages()
+
+}
diff --git a/src/jvmMain/kotlin/JvmAnthropic.kt b/src/jvmMain/kotlin/JvmAnthropic.kt
index db5b2b4..9d5b8f3 100644
--- a/src/jvmMain/kotlin/JvmAnthropic.kt
+++ b/src/jvmMain/kotlin/JvmAnthropic.kt
@@ -16,41 +16,8 @@
 
 package com.xemantic.ai.anthropic
 
-import com.xemantic.ai.anthropic.message.MessageRequest
-import com.xemantic.ai.anthropic.message.MessageResponse
-import kotlinx.coroutines.runBlocking
-import java.util.function.Consumer
-
 actual val envApiKey: String?
   get() = System.getenv("ANTHROPIC_API_KEY")
 
 actual val missingApiKeyMessage: String
   get() = "apiKey is missing, it has to be provided as a parameter or as an ANTHROPIC_API_KEY environment variable."
-
-// a very early version of Java only SDK, adapting Kotlin idioms and coroutines
-// it might change a lot in the future
-class JavaAnthropic {
-
-  companion object {
-
-    @JvmStatic
-    fun create(): Anthropic = Anthropic()
-
-    @JvmStatic
-    fun create(
-      configurer: Consumer<Anthropic.Config>
-    ): Anthropic {
-      return Anthropic { configurer.accept(this) }
-    }
-
-  }
-
-}
-
-fun Anthropic.createMessage(
-  builder: Consumer<MessageRequest.Builder>
-): MessageResponse = runBlocking {
-  messages.create {
-    builder.accept(this)
-  }
-}
diff --git a/src/jvmTest/java/com/xemantic/ai/anthropic/JavaAnthropicTest.java b/src/jvmTest/java/com/xemantic/ai/anthropic/JavaAnthropicTest.java
new file mode 100644
index 0000000..961a255
--- /dev/null
+++ b/src/jvmTest/java/com/xemantic/ai/anthropic/JavaAnthropicTest.java
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2024 Kazimierz Pogoda / Xemantic
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.xemantic.ai.anthropic;
+
+import com.xemantic.ai.anthropic.content.Text;
+import com.xemantic.ai.anthropic.message.Message;
+import com.xemantic.ai.anthropic.message.MessageResponse;
+import com.xemantic.ai.anthropic.message.Role;
+import org.junit.Test;
+
+import java.util.List;
+
+public class JavaAnthropicTest {
+
+  @Test
+  public void foo() {
+    JavaAnthropic anthropic = JavaAnthropic.create(config -> {
+    });
+    MessageResponse response = anthropic.messages.createBlocking(builder -> builder.messages(
+        new Message(
+            Role.USER,
+            List.of(
+                new Text(
+                    "Hi Claude",
+                    null
+                )
+            )
+        )
+    ));
+    System.out.println(response);
+    throw new RuntimeException("test");
+  }
+
+}