stack-kotlin-ktor-patterns

name	stack-kotlin-ktor-patterns
description	Kotlin Ktor web framework — routing, content negotiation, serialization, plugins
license	Apache-2.0
metadata	{"author":"manuel-retamozo-garcia","version":"1.0"}
capabilities	["kotlin"]

Ktor Server Patterns

Comprehensive Ktor patterns for building robust, maintainable HTTP servers with Kotlin coroutines.

When to Use

• Building Ktor HTTP servers
• Configuring Ktor plugins (Auth, CORS, ContentNegotiation, StatusPages)
• Implementing REST APIs with Ktor
• Setting up dependency injection with Koin
• Writing Ktor integration tests with testApplication
• Working with WebSockets in Ktor

Core Rules

1. Clean Route DSL: Keep route files thin, delegates endpoints using extension functions like Route.userRoutes(). Delegate logic to services, not in the route bodies.
2. Content Negotiation: Use kotlinx.serialization for content negotiation, configuring the JSON parser with explicit settings (ignoreUnknownKeys = true, explicitNulls = false).
3. Robust Error Handling: Handle exceptions centrally using the StatusPages plugin, mapping custom domain exceptions (e.g. NotFoundException) to appropriate HTTP status codes.
4. JWT Authentication: Protect resources by nesting them inside authenticate("jwt") blocks. Extract credentials safely using principal<JWTPrincipal>().
5. Dependency Injection: Initialize services, repositories, and database connection instances using Koin. Inject dependencies into routes using by inject().

References

For full code examples, project layout structures, Custom Serializers, WebSockets connections, and BearerAuth integration tests, refer to:

• Kotlin Ktor Web Framework Patterns & Examples