Architecture Patterns
secondsky/claude-skills
Implement proven backend architecture patterns including Clean Architecture, Hexagonal Architecture, and Domain-Driven Design.
Runs a five-step analysis of a monolith: size components, find shared domain logic, flatten hierarchy, measure coupling and group components into candidate domains.
Install Modular Decomposition
$ npx skills add tech-leads-club/agent-skills --skill modular-decomposition -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install tech-leads-club/agent-skills modular-decomposition --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/tech-leads-club/agent-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/'packages/skills-catalog/skills/(architecture)/modular-decomposition' .claude/skills/modular-decomposition && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "modular-decomposition" agent skill from https://github.com/tech-leads-club/agent-skills/tree/main/packages/skills-catalog/skills/(architecture)/modular-decomposition into .claude/skills/modular-decomposition/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "modular-decomposition", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/tech-leads-club/agent-skills/tree/main/packages/skills-catalog/skills/(architecture)/modular-decompositionType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add tech-leads-club/agent-skills --skill modular-decomposition -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install tech-leads-club/agent-skills modular-decomposition --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/tech-leads-club/agent-skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/'packages/skills-catalog/skills/(architecture)/modular-decomposition' .agents/skills/modular-decomposition && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "modular-decomposition" agent skill from https://github.com/tech-leads-club/agent-skills/tree/main/packages/skills-catalog/skills/(architecture)/modular-decomposition into .agents/skills/modular-decomposition/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "modular-decomposition", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add tech-leads-club/agent-skills --skill modular-decomposition -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install tech-leads-club/agent-skills modular-decomposition --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/tech-leads-club/agent-skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/'packages/skills-catalog/skills/(architecture)/modular-decomposition' .cursor/skills/modular-decomposition && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "modular-decomposition" agent skill from https://github.com/tech-leads-club/agent-skills/tree/main/packages/skills-catalog/skills/(architecture)/modular-decomposition into .cursor/skills/modular-decomposition/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "modular-decomposition", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/tech-leads-club/agent-skills.git --path 'packages/skills-catalog/skills/(architecture)/modular-decomposition'--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add tech-leads-club/agent-skills --skill modular-decomposition -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install tech-leads-club/agent-skills modular-decomposition --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/tech-leads-club/agent-skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/'packages/skills-catalog/skills/(architecture)/modular-decomposition' .gemini/skills/modular-decomposition && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "modular-decomposition" agent skill from https://github.com/tech-leads-club/agent-skills/tree/main/packages/skills-catalog/skills/(architecture)/modular-decomposition into .gemini/skills/modular-decomposition/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "modular-decomposition", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install tech-leads-club/agent-skills modular-decompositionInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add tech-leads-club/agent-skills --skill modular-decomposition -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/tech-leads-club/agent-skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/'packages/skills-catalog/skills/(architecture)/modular-decomposition' .github/skills/modular-decomposition && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "modular-decomposition" agent skill from https://github.com/tech-leads-club/agent-skills/tree/main/packages/skills-catalog/skills/(architecture)/modular-decomposition into .github/skills/modular-decomposition/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "modular-decomposition", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add tech-leads-club/agent-skills --skill modular-decomposition -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install tech-leads-club/agent-skills modular-decomposition --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/tech-leads-club/agent-skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/'packages/skills-catalog/skills/(architecture)/modular-decomposition' .opencode/skills/modular-decomposition && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "modular-decomposition" agent skill from https://github.com/tech-leads-club/agent-skills/tree/main/packages/skills-catalog/skills/(architecture)/modular-decomposition into .opencode/skills/modular-decomposition/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "modular-decomposition", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
modular-decomposition- GitHub stars
- 7k
- Token cost
- ~1.7k tokens
- SKILL.md length
- 557 words
- Files
- 13 (incl. references)
- Skills in repo
- 74
- Repo updated
- First seen
- Licence
- Custom licence
At a glance
Runs a five-step analysis of a monolith: size components, find shared domain logic, flatten hierarchy, measure coupling and group components into candidate domains.
- Works in 6 steps: Scope: Confirm the task is structural… → Order: Run patterns 1 → 2 → 3 → 4 → 5 in… → Load references: For each pattern, open… → …
- Deciding how to split a monolith before extracting any services
- SKILL.md covers How to Use, Prerequisites, Ordered workflow (Patterns 1–5) and Pattern 6 — planning and…, plus 1 more section
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
The skill runs five numbered patterns in order against your repository before any service extraction: identify and size components, find common domain logic, fix flattening and hierarchy problems, analyze coupling, then group components by domain. Each pattern is a markdown file under `references/` that the agent loads for its step, and short quick-reference versions exist for most of them.
Results from earlier steps feed later ones, so the component inventory shapes the coupling and grouping analysis. For Pattern 5 it can add domain-driven design strategic analysis of subdomains and bounded contexts using `references/domain-analysis.md`. If you limit the scope, the agent states which patterns were skipped and what that does to later conclusions.
The output is a report per pattern or one combined report, tied to files, dependencies and metrics in your repo. Extraction order and phased roadmaps belong to a separate decomposition-planning-roadmap skill.
When your agent uses it
- Deciding how to split a monolith before extracting any services
- Sizing components to see which are good candidates for extraction
- Finding duplicated domain logic spread across modules
- Measuring coupling between packages or modules
Example prompts
- “Inventory and size the components under src/ and tell me which could be extracted.”
- “Find duplicated domain logic across our billing and orders modules.”
- “Group these modules into domains and check the bounded contexts with DDD.”
Workflow steps
6 steps, taken from the first numbered list in SKILL.md.
- Scope: Confirm the task is structural analysis (inventory → coupling → grouping), not roadmap authoring. If unclear, ask once whether they…
- Order: Run patterns 1 → 2 → 3 → 4 → 5 in that order. Do not skip a step unless the user explicitly limits scope; if they do, state which…
- Load references: For each pattern, open the matching references/pattern-NN-*.md file and follow its instructions. Use the optional…
- Carry context forward: Reuse outputs from earlier patterns in later ones (e.g. component inventory from Pattern 1 informs coupling in 4…
- Domain language (Pattern 5): If subdomains or bounded contexts need grounding beyond structure, read references/domain-analysis.md before…
- Deliver: Produce clear, actionable findings per pattern or one consolidated report—always tied to evidence from the repository (files…
What it can do on your machine
Read from SKILL.md and the folder at commit 6df68d5. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Modular Decomposition loads about 1.7k tokens when it runs, and up to ~35k if it reads all its reference files. Until then it costs about 223 tokens; SKILL.md has 557 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
Its licence (Custom licence) doesn't allow us to republish the file, so here is its outline and opening line. It has 557 words (~1,731 tokens).
“This skill runs the Patterns 1–5 analysis pipeline before service extraction. Each pattern is plain markdown under references/; load the file for that step and execute it against the user’s codebase.”
- name
- modular-decomposition
Files
SKILL.md and 12 other files (references) in packages/skills-catalog/skills/(architecture)/modular-decomposition of tech-leads-club/agent-skills.
- SKILL.md
- references/domain-analysis-examples.md
- references/domain-analysis-quick-reference.md
- references/domain-analysis.md
- references/pattern-01-identify-and-size-quick-reference.md
- references/pattern-01-identify-and-size.md
- references/pattern-02-common-domain-quick-reference.md
- references/pattern-02-common-domain.md
- references/pattern-03-flattening-quick-reference.md
- references/pattern-03-flattening.md
- references/pattern-04-coupling.md
- references/pattern-05-domain-grouping-quick-reference.md
- references/pattern-05-domain-grouping.md
Open the folder on GitHubat commit 6df68d5
Compare with similar skills
Modular Decomposition next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Modular Decomposition this skilltech-leads-club/agent-skills | 7k | — | ~1.7k | Automated safety check: Pass | Custom licence | |
| Architecture Patternssecondsky/claude-skills | 227 | 11 repos | ~2.4k | Automated safety check: Pass | MIT | |
| Architecture PatternsKartikLabhshetwar/better-shot | 2.4k | 2 repos | ~1.4k | Automated safety check: Pass | Custom licence | |
| Brooks Audithyhmrright/brooks-lint | 1.5k | 1 repos | ~537 | Automated safety check: Pass | MIT | |
| Birdview ReviewQiuner/birdview | 727 | — | ~580 | Automated safety check: Pass | MIT | |
| Py Rigmudrii/hermesd | 118 | — | ~6.3k | Automated safety check: Pass | MIT |
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Related
Categories
Questions about Modular Decomposition
What does Modular Decomposition do?
Runs a five-step analysis of a monolith: size components, find shared domain logic, flatten hierarchy, measure coupling and group components into candidate domains. The skill runs five numbered patterns in order against your repository before any service extraction: identify and size components, find common domain logic, fix flattening and hierarchy problems, analyze coupling, then group components by domain. Each pattern is a markdown file under `references/` that the agent loads for its step, and short quick-reference versions exist for most of them.
When should I use Modular Decomposition?
Modular Decomposition fits situations like: deciding how to split a monolith before extracting any services; sizing components to see which are good candidates for extraction; finding duplicated domain logic spread across modules; measuring coupling between packages or modules.
How do I install Modular Decomposition in Claude Code?
Run `npx skills add tech-leads-club/agent-skills --skill modular-decomposition -a claude-code`. Or copy the skill folder (packages/skills-catalog/skills/(architecture)/modular-decomposition in tech-leads-club/agent-skills) into .claude/skills/modular-decomposition in your project. Claude Code loads it when a task matches its description.
How do I install Modular Decomposition in Codex?
Run `npx skills add tech-leads-club/agent-skills --skill modular-decomposition -a codex`. Or copy the skill folder (packages/skills-catalog/skills/(architecture)/modular-decomposition in tech-leads-club/agent-skills) into .agents/skills/modular-decomposition in your project. Codex loads it when a task matches its description.
Can I use Modular Decomposition in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add tech-leads-club/agent-skills --skill modular-decomposition -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/modular-decomposition, .gemini/skills/modular-decomposition, .github/skills/modular-decomposition and .opencode/skills/modular-decomposition in your project.
What does Modular Decomposition need to run?
SKILL.md names no scripts, command-line tools or credentials: Modular Decomposition is instructions for the agent only.
Does Modular Decomposition access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Modular Decomposition safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Modular Decomposition use?
Modular Decomposition has a licence file (the repository's licence) that doesn't match a standard licence. Read it on GitHub before reusing the skill.
How many tokens does Modular Decomposition use?
About 1.7k tokens (SKILL.md is roughly 6.9k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 33k tokens, read only when the agent opens those files.
What are the alternatives to Modular Decomposition?
Skills that share tags, products or a category with Modular Decomposition: Architecture Patterns (secondsky/claude-skills, 227 stars), Architecture Patterns (KartikLabhshetwar/better-shot, 2.4k stars), Brooks Audit (hyhmrright/brooks-lint, 1.5k stars) and Birdview Review (Qiuner/birdview, 727 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Modular Decomposition?
tech-leads-club (a GitHub organization) maintains it in tech-leads-club/agent-skills, which has 7,043 GitHub stars. The repository holds 74 skills in this directory. The repository was last updated on October 8, 2026.
Source: tech-leads-club/agent-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.