diff --git a/transport/message/encoding.go b/transport/message/encoding.go
index 21e5f8c..0edd52b 100644
--- a/transport/message/encoding.go
+++ b/transport/message/encoding.go
@@ -2,3 +2,12 @@ package message
 
 // Encoder is a function that can encode a object to the encoded format.
 type Encoder func(any) ([]byte, error)
+
+// Decoder is a function that can decode a format into an object
+type Decoder func(any, []byte) error
+
+// Codec is a type that can has a matching Encoder and Decoder function.
+type Codec struct {
+	Encoder Encoder
+	Decoder Decoder
+}