http4k - HTTP toolkit written in Kotlin that enables the serving and consuming of HTTP services in a functional and consistent way

http4k is an HTTP toolkit written in Kotlin that enables the serving and consuming of HTTP services in a functional and consistent way. It consists of a core library http4k-core providing a base HTTP implementation + a number of abstractions for various functionalities (such as servers, clients, templating etc) that are provided as optional add-on libraries.

http4k apps can be simply mounted into a running Server, Serverless platform, or compiled to GraalVM and run as a super-lightweight binary. In a single line of code you can switch your server between Java (built-in), Apache, Jetty, Netty, Undertow, Ktor, or Ratpack. In a single line of code you can also switch your client implementation between Java (built-in), Apache, Jetty, and OkHttp.