--- title: Singleton API Clients in iOS: A Good Practice or an... description: Examines the common Singleton API client pattern in iOS development, outlining its appeal for small projects but highlighting hidden costs as apps scale:... canonical: https://daily.dev/posts/singleton-api-clients-in-ios-a-good-practice-or-an-architectural-trap--vcdotfpp5 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Singleton API Clients in iOS: A Good Practice or an Architectural Trap? | daily.dev og:description: Examines the common Singleton API client pattern in iOS development, outlining its appeal for small projects but highlighting hidden costs as apps scale:... og:url: https://daily.dev/posts/singleton-api-clients-in-ios-a-good-practice-or-an-architectural-trap--vcdotfpp5 og:image: https://api.daily.dev/og/posts/vCdOTfpp5.png og:image:alt: Singleton API Clients in iOS: A Good Practice or an Architectural Trap? og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Singleton API Clients in iOS: A Good Practice or an Architectural Trap? **[Medium](https://daily.dev/sources/medium_js)** · 6 min read · 0 upvotes · 0 comments ## Summary Examines the common Singleton API client pattern in iOS development, outlining its appeal for small projects but highlighting hidden costs as apps scale: hidden dependencies, testing difficulty, global mutable state, and tight coupling. Proposes dependency injection as the preferred alternative — creating a single APIClient instance at app startup and passing it through layers (ViewModel → Repository → APIClient → URLSession) via a protocol. Also covers when singletons are genuinely appropriate (analytics, logging, caching) and addresses URLSession.shared and Alamofire's Session.default in the same context. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Don’t Separate Networking From Your UI — Eliminate It From the App](https://daily.dev/posts/don-t-separate-networking-from-your-ui-eliminate-it-from-the-app-plxe82lqw) · Medium · 1 upvotes · 0 comments - [Borrowing from Kotlin/Android to Architect Scalable iOS Apps in SwiftUI](https://daily.dev/posts/borrowing-from-kotlin-android-to-architect-scalable-ios-apps-in-swiftui-zar5rarxu) · InfoQ · 0 upvotes · 0 comments - [Building A Reusable Http Client In Swift](https://daily.dev/posts/building-a-reusable-http-client-in-swift-uvzy7wzug) · AzamSharp · 1 upvotes · 0 comments - [The Modern Guide to Android SDK Development: Architecture & API Design \(Part 1 of 3\)](https://daily.dev/posts/the-modern-guide-to-android-sdk-development-architecture-api-design-part-1-of-3--97izvnm7x) · ProAndroidDev · 2 upvotes · 0 comments - [Unmasking a hidden singleton](https://daily.dev/posts/unmasking-a-hidden-singleton-n5dz15e17) · monday Engineering · 40 upvotes · 0 comments --- Tags: [#ios](https://daily.dev/tags/ios), [#networking](https://daily.dev/tags/networking), [#swift](https://daily.dev/tags/swift), [#dependency-injection](https://daily.dev/tags/dependency-injection) [View this post on daily.dev](https://daily.dev/posts/singleton-api-clients-in-ios-a-good-practice-or-an-architectural-trap--vcdotfpp5) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Singleton API Clients in iOS: A Good Practice or an Architectural Trap?","url":"https://daily.dev/posts/singleton-api-clients-in-ios-a-good-practice-or-an-architectural-trap--vcdotfpp5","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/singleton-api-clients-in-ios-a-good-practice-or-an-architectural-trap--vcdotfpp5"},"datePublished":"2026-07-24T04:34:24.180Z","dateModified":"2026-07-24T04:35:49.759Z","description":"Examines the common Singleton API client pattern in iOS development, outlining its appeal for small projects but highlighting hidden costs as apps scale:...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/d6ab0a9a223ee01bc82d647f54feb2d2?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/d6ab0a9a223ee01bc82d647f54feb2d2?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Medium","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Medium","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/medium","url":"https://daily.dev/sources/medium_js"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/singleton-api-clients-in-ios-a-good-practice-or-an-architectural-trap--vcdotfpp5","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"ios,networking,swift,dependency-injection","timeRequired":"PT6M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Medium","item":"https://daily.dev/sources/medium_js"},{"@type":"ListItem","position":3,"name":"Singleton API Clients in iOS: A Good Practice or an Architectural Trap?"}]} ```