solid-principles

A Java code-review and refactoring guide based on the SOLID principles, a set of rules for keeping classes focused and easier to change.

In plain words
What is it for?
Use it to review class design, assess whether a class does too much, and plan refactorings that separate responsibilities or reduce dependencies.
Why use it?
It helps identify classes with too many responsibilities, overly broad interfaces, or tightly coupled dependencies before they become difficult to maintain.

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/adamw7/tools/solid-principles
Any agent
npx skills add adamw7/tools --skill solid-principles
Clone the repo
git clone --depth 1 https://github.com/adamw7/tools

Made for: Claude Code, Codex.

Per session 84 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,420 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 $0.00084 $0.01420
Opus 5 $0.00042 $0.00710
Sonnet 5 $0.00017 $0.00284
Haiku 4.5 $0.00008 $0.00142

Measured yesterday against content hash 5580ceab15d1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

solid-principles 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 yesterday.

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.

.claude/skills/solid-principles/SKILL.md · 143 lines

How it starts

The opening of the file, as written. The whole thing — 143 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SOLID Principles Skill

Review and apply SOLID in the tools reactor. The heuristics below are the fast path; long before/after code lives in examples.md next to this file — load it only when a worked example would actually help.

Quick reference

Letter Principle One-liner
S Single Responsibility One class = one reason to change
O Open/Closed Open for extension, closed for modification
L Liskov Substitution Subtypes must be substitutable for base types
I Interface Segregation Many specific interfaces beat one general one
D Dependency Inversion Depend on abstractions, not concretions

S — Single Responsibility

One reason to change.

Detect: imports from unrelated domains · a name containing "And", "Manager" or "Handler" · methods that use none of the fields · you cannot describe the class in one sentence without "and".

Fix: Extract Class / Move Method.

Here: an AdoptionStep is one stage of the adoption and nothing else; ClaudeCodeEnforcerRule.report(...) is the one exit point every enforcer rule funnels its violations through; the uniqueness core knows nothing about its MCP adapter (ArchUnit fails the build if it learns).


O — Open/Closed

New behaviour arrives as a new class, not an edit to an old one.

Detect: an if/else or switch on a type or status that keeps growing · adding a feature means editing a core class.

Fix: Strategy, Template Method, Decorator, Factory.

Here: GitHubRepoAdopter composes a List<AdoptionStep>, so a new stage is a new step, not a branch; a new tree output format is a new ProjectTreeSerializer; BudgetedContext decorates any Context instead of teaching Finder about budgets; AbstractFinder template-methods the depth-bounded traversal and lets subclasses supply only findDirectDependencies.


L — Liskov Substitution

A subtype may not surprise a caller holding the base type.

Read the full file on GitHub · 143 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. yesterday First seen · 143 lines · 84 tokens per session scan A 5580ceab15d1

Subscribe to this mod's changes

solid-principles is a skill published in the GitHub repository adamw7/tools (11 stars, last pushed 4d ago), licensed MIT. It adds 84 tokens to every session and 1,420 once invoked, about $0.0004 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.