403 Frameworks Quarkus Validation

Quarkus Validation Guidelines

Apply Quarkus validation best practices at REST boundaries.

What is covered in this Skill?

• Bean Validation annotations on DTOs and command models
• @Valid and boundary validation in Jakarta REST resources
• Validation groups and custom constraints
• Validation error mapping for client-safe responses
• Consistent handling of invalid inputs across endpoints

Scope: Apply recommendations based on the reference rules and good/bad examples.

Constraints

Before applying validation changes, ensure the project compiles. After improvements, run full verification.

• MANDATORY: Run ./mvnw compile or mvn compile before applying any change
• SAFETY: If compilation fails, stop immediately
• VERIFY: Run ./mvnw clean verify or mvn clean verify after applying improvements
• BEFORE APPLYING: Read the reference for detailed rules and examples

When to use this skill

• Add validation support in Quarkus
• Review Quarkus validation rules
• Improve request validation in Quarkus REST APIs
• Add custom validation constraints in Quarkus
• Validate Quarkus @ConfigMapping properties
• Improve validation error mapping with ExceptionMapper in Quarkus

Workflow

• Read reference and assess project context

Read references/403-frameworks-quarkus-validation.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 validation-related 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/403-frameworks-quarkus-validation.md.