Not sure "selfhosted" is the right term here, but a Quick Search™ for "opensource lawnmower" returns this:
https://github.com/ClemensElflein/OpenMower and https://openmower.de/
Not sure "selfhosted" is the right term here, but a Quick Search™ for "opensource lawnmower" returns this:
https://github.com/ClemensElflein/OpenMower and https://openmower.de/