Quickstart

Depending on your learning situation, there are a number of options to get started with http4k…

Help - I’m new and scared!

Follow a tutorial: There is a step-by-step beginner tutorial. This will get you up and running with a basic buildable project.

I know what I’m doing but would like a helping hand…

From within the IDE

You can create new http4k projects directly from IntelliJ by installing our http4k IntelliJ plugin from the JetBrains Marketplace or directly from the IDE itself. This will allow you to generate a fully set-up http4k project for either Server or Serverless platforms, including Gradle files and using any of the 150+ http4k ecosystem modules.

OR…

Using a friendly web GUI

We have developed a set of useful tools for Developers working with the http4k toolset to turbo-charge app development. Collectively, this is known as the http4k Toolbox. These tools include:

  • A Project Wizard that generates entire bootstrap Server and Serverless project source folders - including fully working starter code, build tooling, extra modules and packaging options.
  • From OpenAPI v2 & V3 specification JSON/YAML, generate an entire working http4k Server, Client and Model objects (generated from JSON Schema) in with either of the standard and http4k-connect client styles.
  • Generate Kotlin Data Class definitions from an inputted JSON, YAML, or XML document.
  • Convert any HTTP request to http4k code - a bit like “convert to CURL” but with your favourite HTTP toolkit!

I’ve got a project and want to add http4k to it

Add http4k into an existing project: This simple example demonstrates how to serve and consume HTTP services using http4k. To install, add these dependencies to your Gradle file:

dependencies {
    
    implementation(platform("org.http4k:http4k-bom:6.12.0.0"))

    implementation("org.http4k:http4k-core")
    implementation("org.http4k:http4k-server-undertow")
    implementation("org.http4k:http4k-client-apache")
}

The following creates a simple endpoint, binds it to a Undertow server then starts, queries, and stops it.

package content.quickstart

import org.http4k.client.ApacheClient
import org.http4k.core.Method
import org.http4k.core.Request
import org.http4k.core.Response
import org.http4k.core.Status.Companion.OK
import org.http4k.server.Undertow
import org.http4k.server.asServer

fun main() {
    val app = { request: Request -> Response(OK).body("Hello, ${request.query("name")}!") }

    val server = app.asServer(Undertow(9000)).start()

    val client = ApacheClient()

    val request = Request(Method.GET, "http://localhost:9000").query("name", "John Doe")

    println(client(request))

    server.stop()
}

I want to see what http4k can do!

We have a page dedicated to how http4k can be used in a variety of scenarios. See http4k In Action.

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