There currently are a variety of options to travel by night train from Bremen (Germany) to Augsburg (Germany), taking between approximately 9 and 10 hours: Namely the NOX 1791 and the ICE 619. These lines are operated by Nox and Deutsche Bahn.
Nox is a new night train between Hamburg and Munich with stops in Bremen and Augsburg. It runs three times a week in each direction from 23 March 2027.
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.
There are two fares: Basic, where changes and cancellation cost a fee, and Flex, which you can change or cancel for free 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.
These trains only have first and second class seats. The cars remain lit throughout the night and the seats cannot be reclined.