Google has introduced Google Sans to the upcoming Android 8.1. It looks great and I want to try it on my OnePlus 5 running stock 7.1.1. Is it possible?
The fonts have now been extracted and repackaged for flashing at XDA-Developers. Basically, just download the zip for "stock ROMs" (verified working for OnePlus devices as stated on the page), flash it with TWRP and you should have it.