architecting-code

A set of software design rules for deciding how code is divided into modules and layers. It focuses on keeping business decisions separate from details such as user interfaces, databases, and frameworks.

In plain words
What is it for?
Use it when choosing module boundaries, dependency directions, plugin structures, shared state, or concurrency boundaries in an application.
Why use it?
It helps prevent tightly connected code, unclear ownership, and changes in one part of a system causing unnecessary work elsewhere.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/rootbr/rooted/architecting-code
Any agent
npx skills add rootbr/rooted --skill architecting-code
Clone the repo
git clone --depth 1 https://github.com/rootbr/rooted

Made for: Claude Code, Codex.

Per session 167 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,349 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00167 $0.02349
Opus 5 $0.00084 $0.01175
Sonnet 5 $0.00033 $0.00470
Haiku 4.5 $0.00017 $0.00235

Measured 2d ago against content hash 8c623dd01765, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

architecting-code 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 2d 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.

plugins/code-quality/skills/architecting-code/SKILL.md · 115 lines

How it starts

The opening of the file, as written. The whole thing — 115 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Architecting Code

Evidence base: Robert C. Martin, Clean Architecture: A Craftsman's Guide to Software Structure and Design (Pearson, 2017). Chapter references cite Clean Architecture unless noted.

Load-bearing rule — architecture is measured by cost of change

Architecture is "the significant design decisions that shape a system, where significant is measured by cost of change" (Booch, via Henney, Foreword). Optimise the kinds of changes the system actually experiences to be cheap, not rare — and size the architecture to the problem, not to a textbook.

The Dependency Rule

  • Source-code dependencies always point toward higher-level policy; details implement interfaces owned by the policy layer — the DIP mechanism that makes the rule enforceable (PART III SOLID summary; Appendix A ROSE)
  • When crossing a boundary, invert the dependency so the caller holds an interface the detail implements (Appendix A, Union Accounting)
  • High-level policy compiles with zero knowledge of UI, database, or framework types — only of the abstractions it owns (Ch 17; Appendix A 4-Tel Vectorization)

SOLID at the module level

  • SRP — every module has exactly one reason to change, defined by one actor/stakeholder (Ch 7; PART III summary)
  • OCP — add new behaviour by adding new code, not by editing existing, already-tested code (Ch 8; PART III summary)
  • LSP — a subtype's contract must allow substitution anywhere the supertype is used, including in tests (Ch 9)
  • ISP — never force a module to depend on interface members it doesn't use; unused methods still pin recompile/redeploy (Ch 10)
  • DIP — high-level policy never imports concretions; details implement policy-owned interfaces; factories sit at the boundary (Ch 11)

Component cohesion (what belongs together)

  • REP — Reuse/Release Equivalence — the granule of reuse is the granule of release; unreleased code is not reusable (Ch 13)
  • CCP — Common Closure — classes that change together belong in the same component (component-level SRP) (Ch 13)
  • CRP — Common Reuse — classes that are used together belong in the same component; never drag unrelated classes along (component-level ISP) (Ch 13)

Read the full file on GitHub · 115 lines

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. 2d ago First seen · 115 lines · 167 tokens per session scan A 8c623dd01765

Subscribe to this mod's changes

architecting-code is a skill published in the GitHub repository rootbr/rooted (21 stars, last pushed 26d ago), licensed Apache-2.0. It adds 167 tokens to every session and 2,349 once invoked, about $0.0008 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 2026-08-30.

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