buf is a parser / compiler as an alternative to protoc https://buf.build/docs/migration-guides/migrate-from-protoc/

Ah, so does the LSP just call out to the Buf binary?

The LSP is one of the subcommands provided by the buf binary. My LSP configuration for protobuf is `buf lsp serve`.

Makes sense, thanks for the clarification.

The lsp is a subcommand of buf, from the page: `buf lsp serve`