| name | 502-frameworks-micronaut-rest |
| description | Use when you need to design, review, or improve REST APIs with Micronaut — including @Controller routes, HTTP status codes, DTOs, Bean Validation, exception handlers, pagination, idempotency, ETag/If-Match, caching headers, versioning, contract-first OpenAPI (OpenAPI Generator), optional runtime OpenAPI via micronaut-openapi, and security annotations. This should trigger for requests such as Review or improve Micronaut @Controller REST APIs; Add validation, error handling, or align controllers with the OpenAPI contract on Micronaut HTTP layer. Part of cursor-rules-java project |
| license | Apache-2.0 |
| metadata | {"author":"Juan Antonio Breña Moral","version":"0.16.0"} |
Micronaut REST API Guidelines
Apply REST design principles for Micronaut HTTP applications.
What is covered in this Skill?
- Semantic HTTP with @Get/@Post/@Put/@Patch/@Delete and HttpResponse status control
- Resource-oriented paths and stable DTO contracts
- @Valid on request bodies with Bean Validation
- Centralized error mapping (ExceptionHandler / problem JSON when applicable)
- Pagination with Pageable and bounded sizes
- OpenAPI contract file (API-first) and OpenAPI Generator for server stubs
- Security annotations (@Secured) on sensitive routes
- Idempotency-Key for retried writes
- ETag / If-Match for optimistic concurrency
- Cache-Control discipline
- API versioning patterns
- ISO-8601 time types in DTOs
Scope: Apply recommendations based on the reference rules and good/bad code examples.
Constraints
Compile before REST refactors; verify after.
- 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
- EDGE CASE: If request scope is ambiguous, stop and ask a clarifying question before applying changes
- EDGE CASE: If required inputs, files, or tooling are missing, report what is missing and ask whether to proceed with setup guidance
When to use this skill
- Review or improve Micronaut @Controller REST APIs
- Add validation, error handling, or align controllers with the OpenAPI contract on Micronaut HTTP layer
Workflow
- Read reference and assess project context
Read references/502-frameworks-micronaut-rest.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/502-frameworks-micronaut-rest.md.
