Quarkus REST API Guidelines
Apply REST API design principles on Quarkus using Jakarta REST (JAX-RS).
What is covered in this Skill?
- 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
- Optional
/openapi via SmallRye; API-first contract maintained in openapi.yaml (codegen)
- Reactive vs blocking considerations; @RunOnVirtualThread
- Security integration at the filter layer
Scope: Apply recommendations based on the reference rules and good/bad code examples.
Constraints
Before applying REST changes, ensure the project compiles. After applying improvements, run full verification.
- 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
- Improve Quarkus REST resources and exception mappers
Workflow
- Read reference and assess project context
Read references/402-frameworks-quarkus-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/402-frameworks-quarkus-rest.md.
1---2name: 402-frameworks-quarkus-rest3description: Use when you need to design, review, or improve REST APIs with Quarkus REST (Jakarta REST) — including resource classes, HTTP methods, status codes, request/response DTOs, Bean Validation, exception mappers, optional runtime OpenAPI exposure (SmallRye), contract-first generation from OpenAPI, content negotiation, pagination, sorting and filtering, API versioning, idempotency (Idempotency-Key), optimistic concurrency (ETag / If-Match), HTTP caching (Cache-Control), API deprecation (Sunset / Deprecation headers), RFC 7807 Problem Details, ISO-8601 for time in contracts, and security-aware boundaries. This should trigger for requests such as 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; Improve Quarkus REST resources and exception mappers. Part of Plinth Toolkit4license: Apache-2.05---6# Quarkus REST API Guidelines
7
8Apply REST API design principles on Quarkus using Jakarta REST (JAX-RS).
9
10**What is covered in this Skill?**
11
12- Resource classes, @Path, HTTP method mapping, and resource URI design
13- Status codes, Location headers, and Response building
14- DTOs and Bean Validation at the boundary; ISO-8601 for date/time fields
15- ExceptionMapper for consistent error JSON (RFC 7807 Problem Details)
16- API versioning strategies (URI path, Accept header)
17- Idempotency with Idempotency-Key header
18- Optimistic concurrency: ETag, If-Match, If-None-Match
19- HTTP caching with Cache-Control headers
20- API deprecation: Sunset and Deprecation headers
21- Pagination, sorting, and filtering query parameters
22- Optional `/openapi` via SmallRye; API-first contract maintained in `openapi.yaml` (codegen)
23- Reactive vs blocking considerations; @RunOnVirtualThread
24- Security integration at the filter layer
25
26**Scope:** Apply recommendations based on the reference rules and good/bad code examples.
27
28## Constraints
29
30Before applying REST changes, ensure the project compiles. After applying improvements, run full verification.
31
32- **MANDATORY**: Run `./mvnw compile` or `mvn compile` before applying any change
33- **PREREQUISITE**: Project must compile before applying REST API improvements
34- **SAFETY**: If compilation fails, stop immediately
35- **BLOCKING CONDITION**: Compilation errors must be resolved by the user before proceeding
36- **VERIFY**: Run `./mvnw clean verify` or `mvn clean verify` after applying improvements
37- **BEFORE APPLYING**: Read the reference for detailed rules and examples
38
39## When to use this skill
40
41- Review or improve JAX-RS resources in a Quarkus project
42- Design HTTP APIs with validation and error handling on Quarkus
43- Add API versioning, idempotency, ETag concurrency, or deprecation headers
44- Implement pagination, sorting, or RFC 7807 Problem Details error responses
45- Improve Quarkus REST resources and exception mappers
46
47## Workflow
48
491. **Read reference and assess project context**
50
51Read `references/402-frameworks-quarkus-rest.md` and inspect the current project setup before proposing changes.
52
532. **Gather scope and decide target improvements**
54
55Identify requested outcomes, constraints, and the minimum safe set of changes to apply.
56
573. **Apply framework-aligned changes**
58
59Implement or refactor configuration/code following the reference patterns and project conventions.
60
614. **Run verification and report results**
62
63Execute appropriate build/tests and summarize what changed, what was verified, and any follow-up actions.
64
65## Reference
66
67For detailed guidance, examples, and constraints, see [references/402-frameworks-quarkus-rest.md](references/402-frameworks-quarkus-rest.md).
gabrielmoreira