Layered Architecture

Layered Architecture is a skill for Claude Code, Codex from niels-emmer/myace. It costs 22 tokens per session (304 once invoked), scanned A, original, MIT.

A guide for structuring Spring Boot applications into controllers, services, and repositories, with clear rules for data objects, transactions, and errors.

In plain words
What is it for?
Use it when designing or reviewing Spring Boot code, deciding where logic belongs, handling database transactions, or mapping errors to HTTP responses.
Why use it?
It keeps HTTP handling, business rules, and database access separate, making the application easier to change and reducing architectural drift.

Skill for Claude CodeCodex

Which agent this was written for is unclear — built for aider. Also seen: mentions Codex; built for aider; mentions OpenCode.

Good fit Use it when designing or reviewing Spring Boot code, deciding where logic belongs, handling database transactions, or mapping errors to HTTP responses.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/niels-emmer/myace/layered-architecture
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add niels-emmer/myace --skill layered-architecture
Clone the repo
git clone --depth 1 https://github.com/niels-emmer/myace

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for Layered Architecture

README.md
[![agentmods](https://agentmods.dev/badge/skills/niels-emmer/myace/layered-architecture/github.svg)](https://agentmods.dev/skills/niels-emmer/myace/layered-architecture)
Your own site
<a href="https://agentmods.dev/skills/niels-emmer/myace/layered-architecture"><img src="https://agentmods.dev/badge/skills/niels-emmer/myace/layered-architecture/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for Layered Architecture

Your own site · 80×15
<a href="https://agentmods.dev/skills/niels-emmer/myace/layered-architecture"><img src="https://agentmods.dev/badge/skills/niels-emmer/myace/layered-architecture.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 22 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 304 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00022 $0.00304
Opus 5 $0.00011 $0.00152
Sonnet 5 $0.00004 $0.00061
Haiku 4.5 $0.00002 $0.00030

Measured 7d ago against content hash 72d436ad2b91, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

Layered Architecture scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

collections/additional/java-spring/skills/layered-architecture/SKILL.md · 25 lines

What it actually says

Purpose

Prevent architectural drift in Spring Boot applications by enforcing clear layer boundaries.

Checklist

  • Controller layer: handles HTTP concerns only (request mapping, validation, response serialization). Never contains business logic or data access.
  • Service layer: contains business logic and transaction boundaries. Never returns JPA entities to controllers — use DTOs or projections.
  • Repository layer: data access only. Spring Data JPA repositories or custom DAO implementations. Never contains business logic.
  • DTO boundaries: controllers receive request DTOs and return response DTOs. Services receive and return domain objects or DTOs. Entities never cross the controller boundary.
  • @Transactional: on service-layer methods, not controllers. Read-only transactions for query methods.
  • Exception hierarchy: domain exceptions (extending RuntimeException) caught at the controller boundary and mapped to appropriate HTTP status codes via @ControllerAdvice.

Expected output

A Spring Boot application where each layer has a single responsibility, entities never reach controllers, and exceptions are consistently mapped to HTTP responses.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago First seen · 25 lines · 22 tokens per session scan A 72d436ad2b91

Subscribe to this mod's changes

Layered Architecture is a skill published in the GitHub repository niels-emmer/myace (1 stars, last pushed 4d ago), licensed MIT. It adds 22 tokens to every session and 304 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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