Idiomatic error handling for requests

[orblivion]

Right now I have a weird thing where I have a function that checks for auth errors, and replies to the request with a json error and otherwise returns a token. I probably want to return an error, but I didn't want to have a lot of boilerplate in the handler.

I could probably create a new error type that automatically becomes a json. And a different variant for 500s, since the error should not be output to the user, but rather logs instead (as I do now but in a less idiomatic way).