omhs 0.1.0 — back after ~5 years.

Mike

1 min read

·

Aug 14, 2026

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A long time ago I wrote a tiny Netty wrapper because I didn’t want to pull heavy dependencies into a project — just Sinatra-like routing. And now, five years later, it’s on Scala 3.

I tried before and dropped it (life got busy). This time it’s done.

What’s in this release:

• Scala 3 alongside 2.13 — same DSL
• Netty 4.1.137, refreshed play-json / circe / jsoniter modules
• Maven Central (omhs-dsl + JSON support)
• CI on both Scala versions

The hard part was the routing macros. On Scala 2, ~> expanded into an anonymous ExecutableRule subclass. Scala 3 quoted macros don’t generate that cleanly, so ExecutableRule now takes a runner: List[ParamDef[_]] => AsyncResult, and the macro only builds that function. Same DSL, different codegen.

Artefacts are here.

How to use:

// scala
import com.github.fntz.omhs._
import com.github.fntz.omhs.playjson.JsonSupport
import RoutingDSL._
import play.api.libs.json.{Format, Json}
import scala.concurrent.Future

case class Person(id: Int, name: String)

@main def main(): Unit = {
  implicit val personJson: Format[Person] = Json.format[Person]
  implicit val personBodyReader: BodyReader[Person] = JsonSupport.reader[Person]()
  implicit val personBodyWriter: BodyWriter[Person] = JsonSupport.writer[Person]()

  import AsyncResult.Implicits._
  import scala.concurrent.ExecutionContext.Implicits.global

  val simpleGetRoute = get("ping") ~> { () =>
    "pong"
  }

  val getWithParamsRoute = get("bar" / string) ~> { (x: String) =>
    s"given: $x"
  }

  val postPersonRoute = post("person" <<< body[Person]) ~> { (p: Person) =>
    val x = p.copy(name = "new")
    Future(x)
  }

  val route1 = new Route().addRules(
    simpleGetRoute,
    getWithParamsRoute,
    postPersonRoute
  )

  val server = OMHSServer.init(9000, route1.toHandler(Setup.default), None)

  server.start()

  sys.addShutdownHook(server.stop())
  new java.util.concurrent.CountDownLatch(1).await()
}