Let us start here, from square one. No, from Zero!

api/modules/keypads.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include "api/module.h"
+#include "api/request.h"
+
+namespace api::modules {
+
+    class Keypads : public Module {
+    public:
+        Keypads();
+
+    private:
+
+        // function definitions
+        void write(Request &req, Response &res);
+        void set(Request &req, Response &res);
+        void get(Request &req, Response &res);
+    };
+}