Your first API

Build a small JSON API with only the atlantus CLI.

1. Scaffold

atlantus new hello-api
cd hello-api

2. Add a route module

Create app/routes/hello.atl:

module hello

get "/hello" {
  def hello(req) {
    return json({ message: "Hello, Atlantus!" })
  }
}

get "/hello/{name}" {
  def hello_name(req) {
    let name = req.param("name")
    return json({ message: "Hello, " + name + "!" })
  }
}

3. Wire the module

Open the scaffold entry (usually app/main.atl or app/routes/mod.atl) and import your module the same way other route modules are imported in the generated tree. If the scaffold already globs routes, a new file under app/routes/ may be enough — run atlantus check and fix any “unknown module” diagnostics.

Typical pattern:

import routes.hello

(Exact import syntax follows your generated app/ layout — prefer matching existing imports in the scaffold.)

4. Run

atlantus check --path .
atlantus dev --path . --port 3000

curl -sS http://127.0.0.1:3000/hello
curl -sS http://127.0.0.1:3000/hello/Ada

5. HTML page (optional)

get "/hi/{name}" {
  def hi(req) {
    let name = req.param("name")
    return view("hello/show", { "name": name })
  }
}

app/views/hello/show.html:

@extends("layouts/app")
@section("content")
<h1>Hello, {{ name }}!</h1>
@endsection

See HTML views.

Response helpers

More: Built-in API.

Checklist

• atlantus check green
• Route listed when atlantus dev starts
• curl returns the expected JSON

Next: Project layout.