AnnotateError wraps an error with a message that is intended for a human end-user to read, plus an associated HTTP error code.

HandleLogin is a Handler that redirects the user to Twitch for login, and provides the 'state' parameter which protects against login CSRF.

HandleOauth2Callback is a Handler for oauth's 'redirect_uri' endpoint; it validates the state token and retrieves an OAuth token from the request parameters.

HandleRoot is a Handler that shows a login button.

HumanReadableWrapper implements HumanReadableError.

HumanReadableError represents error information that can be fed back to a human user.