getting field_id when creating new field

Hello.

Which hook should I use so that after I create new custom field I can call a function inside my extension which will be able to access/get ‘field_id’ of the created custom field?

At the moment I do it with ‘sessions_start’ which calls specific functions that preforms check if the custom field was created, but I wont be able to access “field_id” data with that approach since EE inserts sql data to EE_weblog_fields after that (which assigns an id to it).

Many thanks in advance!