In June, Mu3e took three weeks of muon beam at PSI. For the first time we operated the vertex pixel detcteor, scintillating fibre and scintillating tile modules together in the experimental environment. We demonstrated stable data taking at rates of up to 107 muons/s, could synchronize all detector systems, performed real-time reconstruction on GPUs and deployed the our data quality monitoring framework. The vertex detector was succesfully cooled using Helium gas. The beam time helped us to gain valuable operational experience and to iron out many wrinkles in the intricate soft- and firmware.
