The README states > Currently it supports only files generated by Arq (the program) versions 4.5 and above. `arq` however implements the [Arq 5 data format](https://www.arqbackup.com/arq_data_format.txt) but not the [Arq 7 data format](https://www.arqbackup.com/documentation/arq7/English.lproj/dataFormat.html).