XBee USB Adapter Reimplement Interface

I have an XBee SB2 in API Mode 2, connected via Xbee USB Adapter.

In XCTU I see frames with Len/Checksum fields broken out etc… and my data.

When I write a program to read the incoming data, the serial connection gives me all the headers from the frame: Len/Checksum etc…

Does my code need to reimplement checking checksums, asking for resends etc?
Or has that already been done on the XBee, so I can just consume the data.