diff --git a/proto_1.12.2/src/main/java/mc/core/network/proto_1_12_2/serializers/Mapper.java b/proto_1.12.2/src/main/java/mc/core/network/proto_1_12_2/serializers/Mapper.java
new file mode 100644
index 0000000..167dc43
--- /dev/null
+++ b/proto_1.12.2/src/main/java/mc/core/network/proto_1_12_2/serializers/Mapper.java
@@ -0,0 +1,5 @@
+package mc.core.network.proto_1_12_2.serializers;
+
+public interface Mapper<F, T> {
+    T mapping(F fromObject);
+}