```ditaa
+-------------------+                    +----------------+
|cGRE    API    {io}+------------------->+cGRE  BackEnd   |
+-------------------+                    +--------+-------+
                                                  |
                                                  |
                                                  |
                     +----------------+           |
                     |cBLU   DB    {s}+<----------+
                     +----------------+

```