diff --git a/core/kg/common/interfaces.go b/core/kg/common/interfaces.go
new file mode 100644
index 0000000..daee20e
--- /dev/null
+++ b/core/kg/common/interfaces.go
@@ -0,0 +1,17 @@
+package common
+
+import (
+	"github.com/giolekva/pcloud/core/kg/log"
+	"github.com/giolekva/pcloud/core/kg/model"
+)
+
+type LoggerIface interface {
+	Debug(message string, fields ...log.Field)
+	Info(message string, fields ...log.Field)
+	Warn(message string, fields ...log.Field)
+	Error(message string, fields ...log.Field)
+}
+
+type AppIface interface {
+	GetUser(userID string) (*model.User, error)
+}