Http4s provides a standard interface for defining services and clients. This enables an ecosystem of interchangeable server and client backends.

There are also integrations for entities, metrics, and more. Check out the "Related Projects" section of the navigation menu for the complete list of integrations.


Http4s Ember is a server and client backend developed in the core repository.

libraryDependencies ++= Seq(
  "org.http4s" %% "http4s-ember-server" % "1.0.0-M41",
  "org.http4s" %% "http4s-ember-client" % "1.0.0-M41",

Backend Integrations

Backend Platform Http Client Http Server Websocket Client Websocket Server Proxy support (Client)
Ember JDK 8+ / Node.js 16+ / Native
Blaze JDK 8+
Netty JDK 8+
JDK Http Client JDK 11+
Servlet JDK 8+
DOM Browsers
Feral Serverless

Entity Integrations

Http4s has multiple smaller modules for Entity encoding and decoding support of common types.