| name | 503-frameworks-micronaut-validation |
| description | Use when you need to design, review, or improve validation in Micronaut applications — including Bean Validation on @Controller methods, @Body @Valid, query/path parameter validation, @ConfigurationProperties validation, custom constraints, nested DTO validation, and ExceptionHandler mapping for constraint violations. This should trigger for requests such as Add validation support in Micronaut; Review Micronaut validation rules; Improve request validation in Micronaut REST APIs; Add custom validation constraints in Micronaut; Validate Micronaut configuration properties. Part of cursor-rules-java project |
| license | Apache-2.0 |
| metadata | {"author":"Juan Antonio Breña Moral","version":"0.16.0"} |
Micronaut Validation Guidelines
Apply Micronaut validation best practices at HTTP API boundaries.
What is covered in this Skill?
- Bean Validation annotations on DTOs and command models
- @Valid / @Validated usage in Micronaut controllers
- Validation groups and custom validators
- Consistent mapping of validation failures to 400 responses
- Safe and predictable validation error payloads
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 Micronaut
- Review Micronaut validation rules
- Improve request validation in Micronaut REST APIs
- Add custom validation constraints in Micronaut
- Validate Micronaut configuration properties
- Improve constraint violation handling in Micronaut
Workflow
- Read reference and assess project context
Read references/503-frameworks-micronaut-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/503-frameworks-micronaut-validation.md.
