Introduction to Korus Framework
Korus Framework is a Build-Time Dependency Injection (BT-DI) framework designed for ultra-fast Java applications.
It removes reflection, classpath scanning, and runtime dependency wiring entirely — delivering performance comparable to Quarkus and Micronaut while preserving a clean, Spring-like developer experience.
Created and maintained by Vinit Shinde (Aug 2025 – Present).
GitHub Repository: korus-projects
What is Korus?
Korus is a modern Java framework built around annotation processing, compile-time bean creation, and a lightweight Undertow runtime.
All routing, dependency wiring, configuration metadata, and validation logic is generated during compilation, not at runtime.
This enables:
- Zero Reflection
- Zero Classpath Scanning
- Zero Dynamic Proxies
- Instant Startup Times
- Low Memory Footprint
- Strict Compile-time Safety
Korus aims to provide the ergonomics of Spring Boot with the performance profile of Quarkus and Micronaut.
Architecture Overview
Korus uses a two-module architecture:
1. Korus Processor (Build-Time Engine)
Responsible for:
- Annotation scanning & model building
- Generating bean wiring at compile time
- Creating DI registries
- Performing circular dependency detection
- Generating route metadata
- Jandex-based indexing for fast lookups
- Auto-generating a
KorusMainboot class - Eliminating the need for a user-defined
main()method
2. Korus Framework (Runtime Engine)
A lightweight Undertow-powered runtime that:
- Loads pre-generated classes instantly
- Does not perform any reflection
- Does not scan classpath packages
- Uses static indexes + generated registries
- Boots in ~0.12s – 0.25s
Build-Time Dependency Injection
Korus generates concrete bean classes and wiring logic during compilation:
- Direct constructor/method injection written into generated Java files
- Deterministic topological sort for bean initialization
- Compile-time detection of circular dependencies
- Complete removal of runtime scanning and proxies
This gives Korus its signature performance benefits.
Performance Comparison
Below is an approximate comparison of startup times and memory usage:
| Framework | DI Style | Startup Time | Memory |
|---|---|---|---|
| Spring Boot | Runtime | 1.5s – 2.5s | 120–250MB |
| Quarkus | Build-Time | 0.8s – 1.5s | 60–90MB |
| Micronaut | Build-Time | 0.6s – 1.2s | 50–150MB |
| Korus | Build-Time | 0.12s – 0.25s | ~50MB |
Korus competes in the same category as Quarkus/Micronaut —
but focuses on having a cleaner compilation model and a simpler runtime.
Roadmap & Future Improvements
Planned enhancements:
- Multi-Module Architecture (Core, Web, Data)
- Better separation of runtime components
- Source-level architecture improvements inspired by Micronaut
- More flexible configuration system
- First-class modularity support
Next Steps
Now that you understand what Korus is, you can explore:
- How Korus boots with build-time compilation
- How dependency injection works at compile time
- How routes, beans, and registries are generated
- How to create your first Korus application
Check out the documentation to learn more about Korus Framework.