---
name: spring-boot-architecture-04d62dc0ecda
description: Structure Spring Boot 3+ projects with feature packaging and clean layering. Use when structuring Spring Boot 3 projects, defining layers, or applying architecture patterns.
metadata:
  triggers:
    files:
    - 'pom.xml'
    - 'build.gradle'
    keywords:
    - structure
    - layering
    - dto
    - controller
    - "@RestController"
    - "@Service"
    - "@Repository"
    - "@Entity"
    - "@Bean"
    - "@Configuration"
---
# Spring Boot Architecture Standards

## **Priority: P0 (CRITICAL)**

## Organize by Feature

- **Package by Feature**: Prefer `com.app.feature` (e.g., `user`, `order`) over technical layers (`controllers`) for scalability.
- **Dependency Rule**: Outer layers (Web) depend on Inner (Service). Inner layers MUST NOT depend on Outer.
- **DTO Pattern**: ALWAYS use DTOs for API inputs/outputs. NEVER return `@Entity` directly.
- **Java Records**: Use `record` for DTOs to ensure immutability (Java 17+).

See [implementation examples](references/implementation.md) for Java Record DTOs, controller patterns, and global exception handling.

## Define Layer Responsibilities

1. **Controller (Web)**: Handle HTTP, Validation (`@Valid`), DTO mapping. Delegate logic to Service.
2. **Service (Business)**: Transaction boundaries, orchestration. Returns Domain/DTOs.
3. **Repository (Data)**: Database interactions only. Returns Entities/Projections.

## Design API Layer

- **Global Error Handling**: Use `@RestControllerAdvice` with `ProblemDetails` (RFC 7807).
- **Validation**: Use Jakarta Bean Validation (`@NotNull`, `@Size`) on DTOs.
- **Response**: Use `ResponseEntity` for explicit status or `ResponseStatusException`.

## Verification Checklist (Mandatory)

- [ ] **No Entities in API**: all API responses using DTOs/Records instead of JPA Entities?
- [ ] **Validation**: `@Valid` and Jakarta Bean Validation constraints present on all input DTOs?
- [ ] **Layer coupling**: Services depend on Controllers? (Prohibited)
- [ ] **Transactionality**: business transactions correctly bounded with `@Transactional` in Service layer?
- [ ] **Error Details**: `ProblemDetails` used for consistent error responses?

## Anti-Patterns

- **No Fat Controllers**: Move business logic to Services.
- **No Leaking Entities**: Use DTOs instead of JPA Entities in APIs.
- **No Circular Dependencies**: Use Events or refactor to decouple services.
- **No God Classes**: Split large services into single-responsibility components.

## References

- [Implementation Examples](references/implementation.md)

---
Source attribution: HoangNguyen0403
Original project: https://github.com/HoangNguyen0403/agent-skills-standard
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2026 Gabriel Moreira

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: HoangNguyen0403
Original project: https://github.com/HoangNguyen0403/agent-skills-standard
Attribution basis: Upstream repository explicitly recorded in package mirror path

Fields of work: Development & Engineering
Roles: Backend Developer, DevOps / SRE, Full-Stack Developer
Specialties: Backend, Cross Platform
Tools: Spring Boot
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: f8df3a24de074b9a8c507bcf45aa30c06b2cef6f27acdedd0003665cb9d9d6e6