ddd-pattern

ddd-pattern is a skill for Claude Code from hamzaPixl/pixl-ai. It costs 58 tokens per session (970 once invoked), scanned A, original, MIT.

A refactoring guide based on Domain-Driven Design, a way to organize software around the real business concepts it represents.

In plain words
What is it for?
Use it to identify separate business areas, define entities and value objects, organize repositories, enforce valid states, and add domain events.
Why use it?
It helps untangle code when different parts of a system use the same terms differently or when business rules are mixed with technical details.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Part of the pixl-crew plugin — 93 skills, 14 agents, 6 hooks shipped together

Good fit Use it to identify separate business areas, define entities and value objects, organize repositories, enforce valid states, and add domain events.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/hamzapixl/pixl-ai/ddd-pattern
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.

Any agent
npx skills add hamzaPixl/pixl-ai --skill ddd-pattern
Clone the repo
git clone --depth 1 https://github.com/hamzaPixl/pixl-ai

Made for: Claude Code.

Or install pixl-crew, the plugin that ships this one along with the rest of its 93 skills, 14 agents, 6 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for ddd-pattern

README.md
[![agentmods](https://agentmods.dev/badge/skills/hamzapixl/pixl-ai/ddd-pattern.svg)](https://agentmods.dev/skills/hamzapixl/pixl-ai/ddd-pattern)
Your own site
<a href="https://agentmods.dev/skills/hamzapixl/pixl-ai/ddd-pattern"><img src="https://agentmods.dev/badge/skills/hamzapixl/pixl-ai/ddd-pattern.svg" alt="Measured on agentmods" height="20"></a>
Per session 58 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 970 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00058 $0.00970
Opus 5 $0.00029 $0.00485
Sonnet 5 $0.00012 $0.00194
Haiku 4.5 $0.00006 $0.00097

Measured 7d ago against content hash d39f1d45c5ed, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

ddd-pattern 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 7d 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.

packages/crew/skills/ddd-pattern/SKILL.md · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Overview

This skill applies Domain-Driven Design (DDD) tactical and strategic patterns to an existing codebase. It starts with domain discovery — analyzing existing code to identify implicit domain concepts, relationships, and bounded context boundaries. It then models the domain explicitly, separates the domain layer from infrastructure, optionally adds domain events, and verifies the result.

The skill adapts to the target project's language (Python or TypeScript), framework, and existing architecture.

Why DDD matters: Bounded contexts prevent coupling by giving each concept one authoritative home — when "User" means different things in Auth vs Billing, separate models prevent changes in one from breaking the other. Private constructors on entities enforce domain invariants at the creation boundary, making invalid states unrepresentable.

Required References

Before starting, read references/backend/ddd-patterns.md for tactical patterns (entities, value objects, aggregates, repositories, domain events).

Step 1: Discovery

Analyze existing code to identify domain concepts, map relationships between entities, detect implicit bounded contexts, and catalog business rules buried in service or controller code.

If the user provides a domain analysis or explicit model, parse it into discovery format and skip to Step 2.

Actions:

  1. Scan the codebase for entity-like classes, service classes, and data models
  2. Identify implicit domain concepts from naming, relationships, and business logic
  3. Map relationships between entities (associations, dependencies, event flows)
  4. Detect bounded context boundaries (where concepts change meaning)
  5. Catalog business rules currently embedded in controllers/services

Step 2: Model

Define bounded contexts with clear boundaries, model entities with identity and lifecycle, extract value objects for descriptive concepts, define aggregates with invariants and consistency boundaries.

Key patterns (see reference.md for details):

Read the full file on GitHub · 85 lines

Files

What ships with it

1 file 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. 7d ago First seen · 85 lines · 58 tokens per session scan A d39f1d45c5ed

Subscribe to this mod's changes

ddd-pattern is a skill published in the GitHub repository hamzaPixl/pixl-ai (2 stars, last pushed 4mo ago), licensed MIT. It adds 58 tokens to every session and 970 once invoked, about $0.0003 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 2026-08-31.

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