Introduction

The best first step is the guided Creating Your First Kora Application tutorial. It walks through a minimal HTTP service and explains how @KoraApp, @Component, @HttpController, and @HttpRoute fit together in a real Gradle project.

Use the documentation in two complementary ways:

• Guides are step-by-step tutorials. They explain the concepts, the code shape, and the reasoning behind each module.
• Repository examples are complete runnable services. They are useful when you want to compare your project with a working application or copy a proven setup.

Every guide and every example targets the same toolchain: JDK 25, Gradle 9.5+, the io.koraframework:kora-bom BOM, and, for Kotlin, Kotlin 2.4.10 with KSP 2.3.11. The toolchain itself is described in Compatibility and Build System.

Guided Learning Path

Start with the basics:

• Creating Your First Kora Application - build and run the smallest useful HTTP service.
• Dependency Injection Introduction and Dependency Injection - learn Kora's compile-time graph, components, modules, tags, and factories.
• HOCON Configuration, YAML Configuration and JSON - add the common foundation every service needs.

Then move to application features:

• HTTP and API: HTTP Server, Advanced HTTP Server, HTTP Client, Advanced HTTP Client, OpenAPI HTTP Server, Advanced OpenAPI HTTP Server, and OpenAPI HTTP Client.
• Data access: JDBC Database, Advanced JDBC Database, and Cassandra Database.
• Integration modules: Kafka Messaging, gRPC Server, Advanced gRPC Server, gRPC Client, Advanced gRPC Client, and S3.
• Production concerns: Cache, Multi-Level Cache, Resilience, and Validation.
• Observability: Metrics, Tracing, and Probes.
• Testing: Component Testing, Integration Testing, and Black-Box Testing.

Many guides also link to finished Java and Kotlin applications in the kora-examples repository, so you can read the tutorial and immediately inspect the complete project structure.

Repository Examples

A large number of complete services using different Kora modules can be found in the kora-examples repository.

Useful starting points include:

Java Kotlin

• Hello World service
• CRUD service
• HTTP server
• HTTP client
• JDBC database
• Kafka
• OpenAPI HTTP server generation
• OpenAPI HTTP client generation
• PetClinic application

Each example service includes tests that show how to verify the application with the Kora JUnit 5 extension and how to run black-box checks with Testcontainers.

• Hello World service
• CRUD service
• HTTP server
• HTTP client
• JDBC database
• Kafka
• OpenAPI HTTP server generation
• OpenAPI HTTP client generation
• PetClinic application

Each example service includes tests that show how to verify the application with the Kora JUnit 5 extension and how to run black-box checks with Testcontainers.

The finished applications that the guides themselves build live next to the examples, under guides/java and guides/kotlin.

Project Templates

Java Kotlin

You can create a new Java service with the Kora Java template.

You can create a new Kotlin service with the Kora Kotlin template.