--- a/lib/Protobuf-PHP/library/DrSlump/Protobuf/Codec/Json.php
+++ b/lib/Protobuf-PHP/library/DrSlump/Protobuf/Codec/Json.php
@@ -1,1 +1,39 @@
+<?php
 
+namespace DrSlump\Protobuf\Codec;
+
+use DrSlump\Protobuf;
+
+/**
+ * This codec serializes and unserializes from/to Json strings
+ * where the keys represent the field's name.
+ *
+ * It makes use of the PhpArray codec to do the heavy work to just
+ * take care of converting the array to/from Json strings.
+ */
+class Json extends PhpArray
+    implements Protobuf\CodecInterface
+{
+    /**
+     * @param \DrSlump\Protobuf\Message $message
+     * @return string
+     */
+    public function encode(Protobuf\Message $message)
+    {
+        $data = $this->encodeMessage($message);
+        return json_encode($data);
+    }
+
+    /**
+     * @param \DrSlump\Protobuf\Message $message
+     * @param string $data
+     * @return \DrSlump\Protobuf\Message
+     */
+    public function decode(Protobuf\Message $message, $data)
+    {
+        $data = json_decode($data);
+        return $this->decodeMessage($message, $data);
+    }
+
+}
+