diff --git a/anthropic-client/anthropic-client-core/src/commonMain/kotlin/com/tddworks/anthropic/api/messages/api/ContentMessage.kt b/anthropic-client/anthropic-client-core/src/commonMain/kotlin/com/tddworks/anthropic/api/messages/api/ContentMessage.kt
new file mode 100644
index 0000000..0cfeed0
--- /dev/null
+++ b/anthropic-client/anthropic-client-core/src/commonMain/kotlin/com/tddworks/anthropic/api/messages/api/ContentMessage.kt
@@ -0,0 +1,6 @@
+package com.tddworks.anthropic.api.messages.api
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class ContentMessage(val text: String, val type: String)
\ No newline at end of file
diff --git a/anthropic-client/anthropic-client-core/src/commonMain/kotlin/com/tddworks/anthropic/api/messages/api/CreateMessageResponse.kt b/anthropic-client/anthropic-client-core/src/commonMain/kotlin/com/tddworks/anthropic/api/messages/api/CreateMessageResponse.kt
index 9660306..bfde016 100644
--- a/anthropic-client/anthropic-client-core/src/commonMain/kotlin/com/tddworks/anthropic/api/messages/api/CreateMessageResponse.kt
+++ b/anthropic-client/anthropic-client-core/src/commonMain/kotlin/com/tddworks/anthropic/api/messages/api/CreateMessageResponse.kt
@@ -56,18 +56,4 @@ data class CreateMessageResponse(
             )
         )
     }
-}
-
-
-@Serializable
-data class ContentMessage(val text: String, val type: String)
-
-@Serializable
-data class Usage(
-    @SerialName("input_tokens")
-    val inputTokens: Int? = null,
-    @SerialName("output_tokens")
-    val outputTokens: Int? = null,
-)
-
-
+}
\ No newline at end of file
diff --git a/anthropic-client/anthropic-client-core/src/commonMain/kotlin/com/tddworks/anthropic/api/messages/api/Usage.kt b/anthropic-client/anthropic-client-core/src/commonMain/kotlin/com/tddworks/anthropic/api/messages/api/Usage.kt
new file mode 100644
index 0000000..05290a4
--- /dev/null
+++ b/anthropic-client/anthropic-client-core/src/commonMain/kotlin/com/tddworks/anthropic/api/messages/api/Usage.kt
@@ -0,0 +1,12 @@
+package com.tddworks.anthropic.api.messages.api
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class Usage(
+    @SerialName("input_tokens")
+    val inputTokens: Int? = null,
+    @SerialName("output_tokens")
+    val outputTokens: Int? = null,
+)
\ No newline at end of file