I'd like to be able to, ideally, pass in only my protobuf files. These files contain the rpc definitions (with all of the necessary request/response bodies), and the google.api.http option that lets one create a http proxy so that clients can call with either gRPC or json/http. Second best would be a tool that takes in both proto and swagger files to create docs in a uniform manner.
There are plenty of tools to create just OpenAPI documentation, some I've found are https://mrin9.github.io/RapiDoc/ https://lucybot.com/docgen and https://redoc.ly/pricing . These generate pretty docs based on swagger files. But none of them have gRPC support.
The only tool I've found for generating self hosted gRPC documentation is https://github.com/pseudomuto/protoc-gen-doc . The tool is okay, but the UI just isn't at modern standards IMO.
I'm currently using the classic smartbear swagger for my http and protoc-gen-doc for my grpc to create two entirely separate pages for my documentation. But the UI doesn't match up and they are on separate url paths. In an ideal world there would be a toggle on a single page between the two.
I've done a fair bit of research on this topic, so I'm not sure what others will be able to find. At the least perhaps this post will show others that there is a gap in the market. I think gRPC documentation tools could earn someone a lot of money.