Quarkus REST API Guidelines

• Resource classes, @Path, HTTP method mapping, and resource URI design
• Status codes, Location headers, and Response building
• DTOs and Bean Validation at the boundary; ISO-8601 for date/time fields
• ExceptionMapper for consistent error JSON (RFC 7807 Problem Details)
• API versioning strategies (URI path, Accept header)
• Idempotency with Idempotency-Key header
• Optimistic concurrency: ETag, If-Match, If-None-Match
• HTTP caching with Cache-Control headers
• API deprecation: Sunset and Deprecation headers
• Pagination, sorting, and filtering query parameters
• OpenAPI documentation with SmallRye (MicroProfile OpenAPI)
• Reactive vs blocking considerations; @RunOnVirtualThread
• Security integration at the filter layer

Constraints

• MANDATORY: Run

  ./mvnw compile

  or

  mvn compile

  before applying any change
• PREREQUISITE: Project must compile before applying REST API improvements
• SAFETY: If compilation fails, stop immediately
• 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 and examples

When to use this skill

• Review or improve JAX-RS resources in a Quarkus project
• Design HTTP APIs with validation and error handling on Quarkus
• Add API versioning, idempotency, ETag concurrency, or deprecation headers
• Implement pagination, sorting, or RFC 7807 Problem Details error responses

Reference