The fax configuration API allows you to administer:
https://developers.retarus.com/_mock/fax/fax-config-api/
https://fax-config.de2.retarus.com/v2/
View and configure inbound fax numbers
View and configure inbound fax profiles
View and configure email to fax users
View and configure email to fax profiles
Retrieve joined Mail to Fax user and Fax to Mail number