2. Build

This guide will walk through adding functionality to a new application, and explain key concepts as we go. We’ll define some API methods, implement their business logic, and test them. We refer to this process as API-Driven Development.

Part 1: Handling Requests

2.1. Controller

The first section of this guide walks through creating a new Controller, implementing handlers, and configuring routes. We’ll cover how to build endpoints for both REST and GraphQL.

2.2. Service

Controllers typically invoke Services to perform heavy-lifting tasks that aren’t directly related to communicating with the client.

2.3. Policy

Policies decide whether a request should reach a Controller. If you’ll be authenticating users, evaluating permissions, or anything like that, you’ll want to know how to build Policies.

Part 2: Dealing with Data

2.4. Model

If your application deals with data, you’ll want to encapsulate your schema and queries in Models and Resolvers.

2.5. Resolver

Resolvers are to Models as Services are to Controllers. They take care of the work involved with storing/retrieving data to/from the data store.