NewCurrentUserRetrieveHandler returns a handler that fetches current user by token.

NewMessageCreateHandler returns a handler function that creates message.

NewReceivedMessageListHandler returns a handler function that retrieves received messages.

NewSentMessageListHandler returns a handler function that retrieves sent messages.

NewTokenAuthMiddleware returns a middleware that checks token in header.

NewUserAuthenticateHandler returns a handler that returns token.

NewUserCreateHandler returns a handler that creates user.

NewUserListHandler returns a handler that renders the list of users on the server.