An official training agreement between the student, his supervisor, the administrative Head of the hosting lab, the coordinator of the program and the University of Bordeaux must be signed before the traineeship starts.
Once they are enrolled, students can get access to an official template of the training agreement through their personal University Digital Space. They fill it, print 4 copies, sign them and have them signed by the supervisor and the administrative Head of the hosting lab. Agreements are then collected by the Master secretariat, signed by the coordinator of the program and by the President of the University and send back to the different stakeholders.

Laboratories in the University of Bordeaux and in France must provide a monthly stipend to students who spend working more than 2 months in the same lab.
https://www.service-public.fr/particuliers/vosdroits/F32131
That stipend is around 580 EUR/month (4.35 EUR/hour, 35 hours/week).