Models are simple classes that define how the output of your Controllers should look like. To create a model simply create a class that extends the Model class inside Models directory. Make sure to add the @Field decorator to each filed you want to show to the user:

import { Field, Model } from '@Typetron/Models';

export class Article extends Model {
    id: number;

    title: string;

    content: string;

    author: string;

    createdAt: Date;

Having this done, you can use the newly created model inside your controller.

import { Controller, Get } from '@Typetron/Router'; 
import { Article as ArticleModel } from 'App/Models/Article';
import { Article } from 'App/Entities/Article';

class ArticleController {
    async all() {
        return ArticleModel.from(await Article.all());

This is a great way to expose to the user only what fields are needed and not show them fields with sensitive data like password hashes.