ZIO, ZIO HTTP Server, and Scala-Cli

By Alvin Alexander. Last updated: March 31, 2024

As a brief note today, this is a very little ZIO HTTP Server application. I’m sharing it here because it’s currently a fairly simple example, and also because I show how to include the necessary ZIO dependencies using Scala-CLI:

//> using scala "3"
//> using lib "dev.zio::zio::2.0.21"
//> using lib "dev.zio::zio-http::3.0.0-RC4"
//> using lib "dev.zio::zio-json::0.6.2"
package foo

/**
  Helpful ZIO HTTP URLs:
  ----------------------
- https://zio.dev/zio-http/
- https://zio.github.io/zio-http/docs/v1.x/getting-started/
- https://zio.dev/zio-http/getting-started/
*/

// SCALA-CLI NOTES:
// ----------------
// Set up your IDE:
//     scala-cli setup-ide .
// Run me like this:
//     scala-cli ThisFilename.scala

import zio.*
import zio.ZIOAppDefault
import zio.http.*

object ZioHttpServer extends ZIOAppDefault:

    // ZIO HTTP 101:
    // val app = Handler.text("Hello, world").toHttpApp

    val app =
        Routes(
            Method.GET / "todo" -> {
                Handler.text(s"1. wake up\n2. make coffee")
            },
            Method.GET / "blog" / "1" -> 
                handler(Response.text("1st blog post"))
        ).toHttpApp

    def run = Server.serve(app)
                    .provide(Server.defaultWithPort(8888))
                    // OR: provide(Server.default)   // port 8080

In the future I’ll be writing much more about ZIO and ZIO HTTP, but for today, this is a little ZIO HTTP server starter application.

Running the ZIO HTTP server app with Scala-CLI

Before I go, note that you start and run this ZIO HTTP server application like this:

scala-cli ZioHttpServer.scala

This current source code will listen on Port 8888, and once it’s running, you can access the HTTP service with a curl command like this:

curl -i localhost:8090/todo

In summary, if you are interested in seeing a small ZIO HTTP server application, and also how to see it work with Scala-CLI, I hope this example is helpful.

scala

dependencies

http

port

server

ZIO, ZIO HTTP Server, and Scala-Cli

Running the ZIO HTTP server app with Scala-CLI

books by alvin