The ISAN system and ISAN registry are accessible online 24/7.
A public discovery search with limited functionalities and results is available from the ISAN web site ( www.isan.org/lookup/ ). Full search functionalities are free but require credentials obtained from a registration agency.
The ISAN Rest API (www.isan.org/api/) is available for users that need to connect their system or automated workflows to the ISAN registry for searching existing ISAN, retrieving metadata associated to an ISAN (lookup) or for registering content with ISAN. Contact your registration agency or ISAN-IA (firstname.lastname@example.org) if you are interested by implementing the ISAN API.