diff --git a/formatter/license-header.txt b/formatter/license-header.txt
new file mode 100644
index 00000000..df0fa3f7
--- /dev/null
+++ b/formatter/license-header.txt
@@ -0,0 +1,7 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
\ No newline at end of file
diff --git a/gradle/formatting.gradle b/gradle/formatting.gradle
index d6247975..538c0d15 100644
--- a/gradle/formatting.gradle
+++ b/gradle/formatting.gradle
@@ -22,5 +22,10 @@ allprojects {
                 paddedCell()
             }
         }
+        format("license", {
+            licenseHeaderFile("${rootProject.file("formatter/license-header.txt")}", "package ");
+            target("src/main/java/**/*.java")
+            targetExclude("**/netty4/*")
+        })
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/org/opensearch/sdk/ActionListener.java b/src/main/java/org/opensearch/sdk/ActionListener.java
index 33d834f3..75b9ee2e 100644
--- a/src/main/java/org/opensearch/sdk/ActionListener.java
+++ b/src/main/java/org/opensearch/sdk/ActionListener.java
@@ -5,7 +5,6 @@
  * this file be licensed under the Apache-2.0 license or a
  * compatible open source license.
  */
-
 package org.opensearch.sdk;
 
 import org.opensearch.common.SuppressForbidden;
diff --git a/src/main/java/org/opensearch/sdk/ClusterSettingsResponseHandler.java b/src/main/java/org/opensearch/sdk/ClusterSettingsResponseHandler.java
index c1657a96..157ec99e 100644
--- a/src/main/java/org/opensearch/sdk/ClusterSettingsResponseHandler.java
+++ b/src/main/java/org/opensearch/sdk/ClusterSettingsResponseHandler.java
@@ -1,3 +1,10 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
 package org.opensearch.sdk;
 
 import org.apache.logging.log4j.LogManager;
diff --git a/src/main/java/org/opensearch/sdk/ClusterStateResponseHandler.java b/src/main/java/org/opensearch/sdk/ClusterStateResponseHandler.java
index f1b8737e..8375f64f 100644
--- a/src/main/java/org/opensearch/sdk/ClusterStateResponseHandler.java
+++ b/src/main/java/org/opensearch/sdk/ClusterStateResponseHandler.java
@@ -1,3 +1,10 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
 package org.opensearch.sdk;
 
 import org.apache.logging.log4j.LogManager;
diff --git a/src/main/java/org/opensearch/sdk/ExtensionSettings.java b/src/main/java/org/opensearch/sdk/ExtensionSettings.java
index 2ab7f8dc..b69497a5 100644
--- a/src/main/java/org/opensearch/sdk/ExtensionSettings.java
+++ b/src/main/java/org/opensearch/sdk/ExtensionSettings.java
@@ -4,11 +4,7 @@
  * The OpenSearch Contributors require contributions made to
  * this file be licensed under the Apache-2.0 license or a
  * compatible open source license.
- *
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
  */
-
 package org.opensearch.sdk;
 
 /**
diff --git a/src/main/java/org/opensearch/sdk/ExtensionsRunner.java b/src/main/java/org/opensearch/sdk/ExtensionsRunner.java
index 228f49b5..b022495e 100644
--- a/src/main/java/org/opensearch/sdk/ExtensionsRunner.java
+++ b/src/main/java/org/opensearch/sdk/ExtensionsRunner.java
@@ -4,11 +4,7 @@
  * The OpenSearch Contributors require contributions made to
  * this file be licensed under the Apache-2.0 license or a
  * compatible open source license.
- *
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
  */
-
 package org.opensearch.sdk;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
diff --git a/src/main/java/org/opensearch/sdk/LocalNodeResponseHandler.java b/src/main/java/org/opensearch/sdk/LocalNodeResponseHandler.java
index 8a16056b..8df34580 100644
--- a/src/main/java/org/opensearch/sdk/LocalNodeResponseHandler.java
+++ b/src/main/java/org/opensearch/sdk/LocalNodeResponseHandler.java
@@ -1,3 +1,10 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
 package org.opensearch.sdk;
 
 import org.apache.logging.log4j.LogManager;