What is the name of exam that German students take in 8th grade?

There isn't one single, nationwide exam that all German students take in 8th grade. The system varies by state (Bundesland). Some states have a form of assessment at the end of primary school (which would be 4th grade in some regions), while others have exams or assessments at the end of secondary school (which might be 10th or even later depending on the type of secondary school). There's no standard "8th-grade exam" across Germany.