Do you mean from first-principles, or letting someone else do the work and use a framework? Apple did the hard work, https://github.com/apple/swift-nio https:/

Do you mean from first-principles, or letting someone else do the work and use a framework? Apple did the hard work, https://github.com/apple/swift-nio https://github.com/apple/swift-nio. If you just want a big framework to launch an API, that's been around for years: https://vapor.codes https://vapor.codes