Modular Design Principles

Q: What is a Claude Code skill and how does the Modular Design Principles skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Modular Design Principles is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Product category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Product · Sub-category: roadmap · Last updated: 2026-05-21

type:generator type:review

Technology-agnostic guidance for modular systems: bounded contexts, clear boundaries, composability, state isolation, explicit contracts, failure containment, scaffolding workflows, split/merge criteria, sub-units inside a context, and compliance review signals. Use when designing or reviewing module structure, service boundaries, package layout, cross-cutting dependencies, "how should we split this?", modularity assessments, coupling between domains, greenfield context design, or architecture discussions without assuming a specific framework, language, or repository layout. Do NOT use for executing the full Patterns 1–5 repo decomposition pipeline or per-pattern inventories (use modular-decomposition), phased extraction roadmaps as the main deliverable (use decomposition-planning-roadmap), or end-to-end legacy migration strategy (use legacy-migration-planner).

Security AStatic scan found no risk patternsHow grading works ›

From the source SKILL.md

Use this skill when reasoning about structure and boundaries in any codebase. It intentionally avoids framework names, folder conventions, and tooling — map principles to your stack locally.

What this skill does

Modular Design Principles is a community-contributed Claude Code skill in the roadmap sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/modular-design-principles/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use when designing or reviewing module structure, service boundaries, package layout, cross-cutting dependencies, "how should we split this?", modularity assessments, coupling between domains, greenfield context design, or architecture discussions without assuming a specific framework, language, or repository layout. Do NOT use for executing the full Patterns 1–5 repo decomposition pipeline or per-pattern inventories (use modular-decomposition), phased extraction roadmaps as the main deliverable (use decomposition-planning-roadmap), or end-to-end legacy migration strategy (use legacy-migration-planner).

Who uses this skill

The Modular Design Principles Claude Code skill is built for product managers, product designers, and cross-functional teams planning, shipping, and measuring product features. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 190,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/modular-design-principles
curl -L https://claudskills.com/skills/modular-design-principles/SKILL.md \
  -o ~/.claude/skills/modular-design-principles/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/modular-design-principles/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/modular-design-principles/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\modular-design-principles\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Modular Design Principles Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/modular-design-principles/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Modular Design Principles skill do?

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Modular Design Principles skill?

Use Modular Design Principles when your Claude Code task falls under the Product category — specifically in the roadmap area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Modular Design Principles" or describe the task and let Claude pick). Browse related skills at /category/product/.

What is a Claude Code skill and how does the Modular Design Principles skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Modular Design Principles is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Product category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/tech-leads-club/agent-skills/blob/HEAD/packages/skills-catalog/skills/(architecture)/modular-design-principles/SKILL.md
Author: tech-leads-club
Website: https://agent-skills.techleads.club/

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

tech-leads-club. (2026). Modular Design Principles [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/modular-design-principles/

BibTeX

@misc{modular-design-principles-2026,
  author    = {tech-leads-club},
  title     = {Modular Design Principles [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/modular-design-principles/}
}

Embed this skill

Promote, attribute, or link this skill from your own README, blog post, or documentation. All three snippets are free to use — no sign-up, no API key. More distribution surfaces →

Badge

[![ClaudSkills](https://claudskills.com/badge/modular-design-principles.svg)](https://claudskills.com/skills/modular-design-principles/?utm_source=badge&utm_medium=readme&utm_campaign=skill_badge)

Security scan

Grade A · scanned 2026-08-24 — free static scan against the OWASP Agentic Skills Top 10.

No risk patterns were found in any of the ten OWASP-aligned categories. How grading works ›

✓ Prompt injection
✓ Data exfiltration
✓ Supply chain
✓ Reverse shell
✓ Credentials
✓ Execution
✓ Filesystem
✓ Persistence
✓ Obfuscation
✓ Network

Show this grade on your repo (click to copy):

[![Security: A](https://img.shields.io/badge/Security-A-2e7d32)](https://claudskills.com/skills/modular-design-principles/#security)

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