I thought the same @dom96 but I did not post it because obviously a running server is one attack vector more in a system if you otherwise can be "closed".
My [Hubic2SwiftGate](https://github.com/oderwat/hubic2swiftgate) is a program which does something similar: The the whole server is used to answer a callback for OAuth2. But in my case it also is a front end for the authorization request because the original clients don't know how to handle this. Besides that it does not even proxy any requests after the auth-token is received. The remaining communication happens between different endpoints. The only reason why It is running "all the time" is because it needs to be there whenever any client needs an auth token. This was written with PHP and needs a web-server installed but it is obviously a candidate for recoding it with Nim eventually. I do not use it as much as I thought but others do and for long term archiving 10 TB storage for 5 Euro per month is still a very good offering :)
