It may come as a surprise to some Buf users, but the Buf CLI uses a custom Protobuf compiler, written in Go. Instead of shelling out to Google's reference compiler, protoc, the Buf CLI handles compilation of proto source files in process. We've put a lot of effort over the past couple of years into making sure our compiler matches the behavior of protoc, so that the switch to using Buf for new use
![Buf's New Compiler](https://cdn-ak-scissors.b.st-hatena.com/image/square/db496b6b0ea527bb55d5e4963a18f194541f783c/height=288;version=1;width=512/https%3A%2F%2Fbuf.build%2F_next%2Fstatic%2Fmedia%2Fog%402x.554f7517.png)