# domain-driven-design

A skill that makes the agent model code around the business domain: bounded contexts, aggregates, one shared language. Useful when the codebase has drifted away from the business.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 7200 installs · ★ 2508
- Author: wondelai
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/wondelai/skills/tree/HEAD/domain-driven-design/SKILL.md
- Updated: 2026-09-10
- HTML: https://affpapa.org/en/nevibecode/skills/wondelai-domain-driven-design

## What it does

The skill pushes the agent to understand the business before it names anything. Three parts sit inside: a ubiquitous language, bounded contexts with a context map, and the entity, value object and aggregate split. Each comes with a table of code applications, from naming methods after domain verbs to wrapping a legacy system behind an anti-corruption layer.

It also scores the model: 1 point per satisfied row of a quick diagnostic, 7 rows in total, plus up to 3 for depth such as a rich core domain, invariants inside aggregates, language consistent across conversation, code and tests. The agent reports the score and the rows that failed. A 5–6 band means leaky boundaries or anemic objects, so it is worth checking where your logic actually lives.

This is strategic design, not layering. For architecture layers it points at `clean-architecture`, for complexity at `software-design-philosophy`, so it will not hand you a folder skeleton. The language part needs domain experts in the room, since the agent has nothing to derive it from on its own.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add wondelai/skills --skill domain-driven-design -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/domain-driven-design/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/domain-driven-design/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add wondelai/skills --skill domain-driven-design -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/domain-driven-design/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add wondelai/skills --skill domain-driven-design -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/domain-driven-design/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install wondelai/skills domain-driven-design
```

2. **Manually: put the files in place**
- File: `.github/skills/domain-driven-design/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add wondelai/skills --skill domain-driven-design -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/wondelai/skills --path domain-driven-design
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/domain-driven-design/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add wondelai/skills --skill domain-driven-design -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/wondelai/skills/tree/HEAD/domain-driven-design/SKILL.md

## When to use it
- split a monolith along context boundaries
- agree on class names with domain experts
- move invariants out of services and into aggregates
- put an anti-corruption layer in front of a foreign API
- score a domain model against a 7-row checklist

## Example prompts
- Our code doesn't match the business. Map the context boundaries in this repo and name them.
- Break this monolith into services and show me the context map.
- Score the order model with your diagnostic and list the rows that fail.

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: 42713e279e2ef596.

BEGIN THIRD-PARTY FILE 42713e279e2ef596
```text
---
name: domain-driven-design
description: 'Model software around the business domain using bounded contexts, aggregates, and ubiquitous language. Use when the user mentions "domain modeling", "bounded context", "aggregate root", "ubiquitous language", "anti-corruption layer", "context mapping", "domain events", "strategic design", "the code doesnt match the business", or "how do we split this big system". Also trigger when breaking a monolith into services, defining service boundaries, or aligning code structure with business processes. Covers entities vs value objects, domain events, and context mapping strategies. For architecture layers, see clean-architecture. For complexity, see software-design-philosophy.'
license: MIT
metadata:
  author: wondelai
  version: "1.4.0"
---

# Domain-Driven Design Framework

Framework for tackling software complexity by modeling code around the business domain. The greatest risk in software is not technical failure -- it is building a model that does not reflect how the business actually works.

## Core Principle

**The model is the code; the code is the model.** Software should embody a deep, shared understanding of the business domain. When domain experts and developers speak the same language and that language is directly expressed in the codebase, complexity becomes manageable and the system evolves gracefully as the business changes.

## Scoring

**Goal: 10/10.** Score a domain model by awarding **1 point per satisfied row of the Quick Diagnostic** (7 rows) plus up to 3 points for depth: +1 if the Core Domain has a genuinely rich model (not just CRUD), +1 if invariants live inside aggregates rather than in services, +1 if the ubiquitous language is consistent across conversation, code, and tests. Bands: **9-10** = expert-readable names, explicit context boundaries with ACLs, small aggregates, behavior-rich entities, events for cross-aggregate flow, an identified Core Domain; **5-6** = some domain language but leaky boundaries or anemic objects; **<=3** = technical naming, one model for everything, logic scattered in services. Report the score and the specific diagnostic rows failing.

## Framework

### 1. Ubiquitous Language

**Core concept:** A shared, rigorous language between developers and domain experts, used consistently in conversation, documentation, and code. When the language changes, the code changes -- and awkward naming in code feeds back into refining the language.
```
END THIRD-PARTY FILE 42713e279e2ef596

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