The address book can be found in ~/.i2pd/addressbook folder. Consists of files with .b32 names containing full binary (387+) address. File addressbook.csv contains symbolic name to .b32 mapping.

Subscriptions can be enabled by placing subscriptions.txt into ~/.i2pd containing list of hosts.txt sources, like http://i2p-projekt.i2p/hosts.txt.

When i2pd try to resolve an address from adressbook, it looks in addressbook.csv. If addressbook is empty it tries to read ~/.i2pd/hosts.txt and if hosts.txt is not presented it downloads it automatically from http://udhdrtrcetjm5sxzskjyr5ztpeszydbh4dpl3pl4utgqqw2v4jna.b32.i2p/hosts.txt