# Mobile Buy SDK Sample Swift App The Swift sample app demonstrates how to use the SDK within a Swift app. The app includes an Objective-C bridging header. ### Getting started First, add your shop domain, API key and Channel ID to the `ViewController.swift`. ```swift let shopDomain = "" let apiKey = "" let channelId = "" let productId = "" ``` ### Overview The sample app also demonstrates how to use the `BUYClient` to obtain a product by calling `getProductById()`. ```swift client.getProductById(productId) { (product, error) -> Void in } ```