Server-Sent Events as Your Mobile Real-Time Layer

--- title : " SSE on Ktor: Replace 90% of Your WebSocket Use Cases" published : true description : " Build a production-ready Server-Sent Events backend with Ktor and a shared KMP client — automatic reconnection, Last-Event-ID replay, and zero custom sync logic." tags : kotlin, android, mobile, api canonical_url : https://blog.mvpfactory.co/sse-on-ktor-replace-90-percent-of-your-websocket-use-cases --- ## What We Will Build Let me show you a pattern I use in every project that needs real-time server-to-client updates. We will build an SSE-powered order tracking endpoint in Ktor and a shared Kotlin Multiplatform client that runs identically on Android and iOS. By the end, you will have automatic reconnection, missed-event replay via `Last-Event-ID` , and backpressure handled by Kotlin Flows — all in roughly 30 lines of server code. ## Prerequisites - Kotlin 1.9+ and Ktor 3.x (server and client) - Kotlin Multiplatform project targeting Android and iOS - Basic familiarity with Kotlin Flow