Quarkus Core Guidelines
Apply Quarkus core guidelines for CDI beans, configuration, profiles, and lifecycle.
What is covered in this Skill?
- @QuarkusMain and application entry (when custom main is needed)
- CDI scopes: @ApplicationScoped, @Singleton, @Dependent; bean disambiguation (@Default, @Alternative, @Named)
- Constructor injection with @Inject
- CDI interceptors (@Interceptor, @InterceptorBinding) for cross-cutting concerns
- CDI events: @Observes StartupEvent / ShutdownEvent, @ObservesAsync for async dispatch
- Programmatic injection with Instance<T> for dynamic bean selection
- @ConfigMapping and structured configuration with Bean Validation (@Valid)
- Profile-specific properties (%dev, %test, %prod) and @IfBuildProfile
- Startup and shutdown observers (@Startup, @PreDestroy)
- Virtual threads with @RunOnVirtualThread (Java 21+)
- Native-image safety: @RegisterForReflection, @DisabledOnNativeImage
Scope: Apply recommendations based on the reference rules and good/bad code examples.
Constraints
Before applying any Quarkus changes, ensure the project compiles. If compilation fails, stop immediately. After applying improvements, run full verification.
- MANDATORY: Run
./mvnw compile or mvn compile before applying any change
- PREREQUISITE: Project must compile successfully before applying Quarkus core improvements
- SAFETY: If compilation fails, stop immediately — compilation failure is a blocking condition
- BLOCKING CONDITION: Compilation errors must be resolved by the user before proceeding
- VERIFY: Run
./mvnw clean verify or mvn clean verify after applying improvements
- BEFORE APPLYING: Read the reference for detailed rules, good/bad patterns, and constraints
When to use this skill
- Review Java code for Quarkus application structure and CDI
- Apply best practices for Quarkus configuration and beans
- Improve CDI interceptors, events, or programmatic injection in Quarkus
- Add virtual-thread configuration or tune CDI lifecycle
- Review Quarkus CDI bean lifecycle and configuration
Workflow
- Read reference and assess project context
Read references/401-frameworks-quarkus-core.md and inspect the current project setup before proposing changes.
- Gather scope and decide target improvements
Identify requested outcomes, constraints, and the minimum safe set of changes to apply.
- Apply framework-aligned changes
Implement or refactor configuration/code following the reference patterns and project conventions.
- Run verification and report results
Execute appropriate build/tests and summarize what changed, what was verified, and any follow-up actions.
Reference
For detailed guidance, examples, and constraints, see references/401-frameworks-quarkus-core.md.