vapor-docs/3.0/docs/vapor/application.md

Application

Every application in Vapor starts as an Application. Application is a open class, meaning it can be subclassed to add extra properties, but that's usually not necessary.

Application is Extendable, has a Config and Services.

Application may behave differently depending on it's Environment.

Creating a basic application

Creating and running an application is only 2 lines of code.

let application = Application()

// Set up your routes etc..

try application.run()

If not overridden, Application comes with it's own set of default services.

You can override the default config, environment and services like so:

let config: Config = ...
let environment = Environment.production
let services = Services()

// configure services, otherwise there's no Server and Router

Application routing services

In order to add routes to an Application you need to get a router first. The default services set up for Application support AsyncRouter and SyncRouter

let async = try app.make(AsyncRouter.self)
let sync = try app.make(SyncRouter.self)