Ktor Framework Guide

Applies to: Ktor 2.x, Kotlin 1.9+, Microservices, REST APIs, WebSockets

Overview

Ktor is a lightweight, asynchronous framework built by JetBrains for Kotlin. It leverages coroutines for non-blocking I/O and provides a flexible plugin system for extensibility.

Best For: Microservices, lightweight APIs, real-time applications, Kotlin-native projects

Key Characteristics:

• Native Kotlin coroutines (non-blocking by default)
• Modular plugin architecture (install only what you use)
• Type-safe routing DSL
• Built-in test engine (testApplication)
• Multiple server engines: Netty, Jetty, CIO, Tomcat
• First-class WebSocket support
• Multiplatform HTTP client