Scala-Play-Slick-Demo/modules/api/src/main/scala/com/example/models/Library.scala

package com.example.models

import play.api.libs.json.Json
import java.time.Instant

final case class Book(id: Long, title: String, authorId: Long, createdAt: Instant)
final case class NewBook(title: String, authorId: Long)
final case class BookDTO(title: String, authorId: Long, createdAt: Instant)
final case class Author(id: Long, name: String)
final case class NewAuthor(name: String)

object Book {
    implicit val bookJsonWrite = Json.format[Book]
}