There currently are a variety of options to travel by night train from Augsburg (Germany) to Bremen (Germany), taking between approximately 9 and 10 hours: Namely the NOX 1790 and the ICE 618. These lines are operated by Nox and Deutsche Bahn.
From 23 March 2027, Nox runs a night train between Hamburg and Munich, stopping in Bremen and Augsburg, three times a week in each direction.
There is only one category: the Nox Suite, a reclining seat with privacy wings in an open-plan car, with a reading lamp and a small table.
You can book the Basic fare, which can be changed or cancelled for a fee, or the Flex fare, with free changes and cancellation until 3 hours before departure.
Deutsche Bahn (DB) exited the actual night train business in 2016. However, it operates around a dozen Intercity and Eurocity trains that run exclusively at night.
In these night trains, there are only first and second class seats. The lights stay on all the time and there is no way to recline the seats.