Open Source Scala HTTP Servers

Http4s is a minimal, idiomatic Scala interface for HTTP services. Http4s is Scala's answer to Ruby's Rack, Python's WSGI, Haskell's WAI, and Java's Servlets. http4s servers and clients share an immutable model of requests and responses. Standard headers are modeled as semantic types, and entity codecs are done by typeclass. The pure functional side of Scala is favored to promote composability and easy reasoning about your code. I/O is managed through cats-effect. http4s is built on FS2, a streaming library that provides for processing and emitting large payloads in constant space and implementing websockets. http4s cross-builds for Scala.js and Scala Native. Share code and deploy to browsers, Node.js, native executable binaries, and the JVM.

Simple scala wrapper for HttpURLConnection. OAuth included. This is a fully featured http client for Scala which wraps java.net.HttpURLConnection. The library is thread safe. HttpRequest and HttpResponse are immutable. So it should be easy to wrap in an execution framework of your choice. If you're including this in some other public library. Do your users a favor and change the fully qualified name so they don't have version conflicts if they're using a different version of this library. The easiest way to do that is just to copy the source into your project.

The Akka HTTP modules implement a full server- and client-side HTTP stack on top of akka-actor and akka-stream. It’s not a web framework but rather a more general toolkit for providing and consuming HTTP-based services. While interaction with a browser is of course also in scope it is not the primary focus of Akka HTTP. Akka HTTP follows a rather open design and many times offers several different API levels for “doing the same thing”. You get to pick the API level of abstraction that is most suitable for your application. This means that, if you have trouble achieving something using a high-level API, there’s a good chance that you can get it done with a low-level API, which offers more flexibility but might require you to write more application code. Akka HTTP has been driven with a clear focus on providing tools for building integration layers rather than application cores. As such it regards itself as a suite of libraries rather than a framework.

Finch is a thin layer of purely functional basic blocks atop of Finagle for building composable HTTP APIs. Its mission is to provide the developers with simple and robust HTTP primitives being as close as possible to the bare metal Finagle API.