Scala handlers.
Nuxt applications.

Write Nuxt server routes as plain Scala.js functions. h34s runs them on a Kyo core, with a first-class ZIO adapter. Your services stay in your app.

Get started Explore the handler API

Release 0.2.0-alpha.1 is an alpha on GitHub Packages. The repository demo is optional.

Handlers.scala

Your application handler

@JSExportTopLevel("default", "kyo-greeting-post")
val personalizedGreeting: EventHandler = AppHandler
  .define: request =>
      for
        input    <- request.body.json[GreetingRequest]
        greeting <- Env.use[Greetings](_.greet(input.name))
      yield greeting
  .at(Route.post("/api/kyo/greeting"))

@JSExportTopLevel("default", "zio-greeting-post")
val personalizedGreeting: EventHandler = AppHandler
  .define: request =>
      for
        input    <- request.body.json[GreetingRequest]
        greeting <- ZIO.serviceWithZIO[Greetings](_.greet(input.name))
      yield greeting
  .at(Route.post("/api/zio/greeting"))

Define AppHandler to provide your services

POST /api/kyo/greeting response shape

{ "data": { "message": "Hello, Scala!" } }

AppHandler, Greetings and GreetingRequest are your application code.

Tour the whole project

Pick what you need.Scala.jsKyo coreZIO adapterh3NuxtYour database

YOUR STARTING POINT

Start where you are.

One toolbox. Three ways in.
Choose the path that fits your application.

Start a new project

Create a Nuxt app, choose your h34s modules, and add your first Scala handler.

Start building

Bring Scala to Nuxt

Add Scala handlers alongside the TypeScript routes you already have.

Explore the Nuxt path

Bring Nuxt to Scala

Keep your Scala.js models and services. Give them a Nuxt frontend.

Explore the Scala path

FROM REQUEST TO RESPONSE

Build the whole handler.

See the architecture

KYO

Kyo handlers & services

Request in, body out. Wire your services once in your app.

ZIO

The ZIO adapter

Write ordinary ZIO programs over the same core.

APP

Configuration & lifetimes

Read runtime config from Scala. Share pools safely.

DATABASE

PostgreSQL, your way

Plug in kyo-sql or Skunk directly. No wrapper needed.

LIFECYCLE

Streams & cancellation

Keep resources alive until a response finishes.

Debug in Scala

Follow Nuxt errors back to the original Scala source.

SMALL STEPS. CLEAR BOUNDARIES.

A working foundation.
A clear direction.

0.1.0-alpha.1 has the older API. 0.2.0-alpha.1 moves the core to Kyo, adds a ZIO adapter, Scala configuration, shared resources and one schema per model. Routes declared in Scala are on main for the next release; packaging remains planned.

What works today

Scala handlers.Nuxt applications.