domain-modeling

domain-modeling is a skill for Claude Code from elct9620/ai-coding-skills. It costs 0 tokens per session (3,450 once invoked), scanned A, original, Apache-2.0.

A way to describe business concepts as software objects, such as things with identity, descriptive values, grouped rules and events. It follows Domain-Driven Design, a software design approach that keeps code close to the language and rules of the business.

In plain words
What is it for?
Use it when defining business logic, creating domain objects, setting boundaries around groups of related data and modelling business events.
Why use it?
It helps teams decide what the important business concepts are and where their rules belong before building the system.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the coding plugin — 9 skills, 4 commands shipped together

Good fit Use it when defining business logic, creating domain objects, setting boundaries around groups of related data and modelling business events.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/elct9620/ai-coding-skills/domain-modeling
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 elct9620/ai-coding-skills --skill domain-modeling
Clone the repo
git clone --depth 1 https://github.com/elct9620/ai-coding-skills

Made for: Claude Code.

Or install coding, the plugin that ships this one along with the rest of its 9 skills, 4 commands.

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 domain-modeling

README.md
[![agentmods](https://agentmods.dev/badge/skills/elct9620/ai-coding-skills/domain-modeling/github.svg)](https://agentmods.dev/skills/elct9620/ai-coding-skills/domain-modeling)
Your own site
<a href="https://agentmods.dev/skills/elct9620/ai-coding-skills/domain-modeling"><img src="https://agentmods.dev/badge/skills/elct9620/ai-coding-skills/domain-modeling/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for domain-modeling

Your own site · 80×15
<a href="https://agentmods.dev/skills/elct9620/ai-coding-skills/domain-modeling"><img src="https://agentmods.dev/badge/skills/elct9620/ai-coding-skills/domain-modeling.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,450 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00000 $0.03450
Opus 5 $0.00000 $0.01725
Sonnet 5 $0.00000 $0.00690
Haiku 4.5 $0.00000 $0.00345

Measured 9d ago against content hash 10d9aa807185, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

domain-modeling 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 9d 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.

skills/domain-modeling/SKILL.md · 343 lines

How it starts

The opening of the file, as written. The whole thing — 343 lines — stays where its author put it; the contents beside it link to each section on GitHub.

  • Need to persist domain objects? → Use schema for database table design
  • Deciding how to structure classes around patterns? → Use design-patterns
  • Deciding how the system is structured — layers, modules, where the domain layer lives? → Use architecture. Structure follows the model, so the aggregate boundaries you settle here are what it mirrors.

Relationship to architecture

Domain modelling and architecture are different kinds of problem. This skill decides what the domain concepts are — Entity, Value Object, Aggregate, Domain Event. architecture decides how the system is structured around them.

The link runs in one direction: structure follows the model. A bounded context's boundary normally aligns with the aggregate boundaries defined here, so this tactical work comes first and the strategic layout mirrors it — which is why architecture defers context partitioning to these boundaries rather than inventing its own.

This skill is for when the domain is thick enough to model explicitly — rich invariants, real aggregates, ubiquitous-language tension. If the system is small and CRUD-heavy with no invariants worth enforcing, the tactical vocabulary is overhead; keep the domain objects plain. Whether to add surrounding structure at all is architecture's force judgement, not a precondition for this skill.

Applicability Rubric

Condition Pass Fail
Rich invariants Business rules span multiple fields/objects and must hold together Field-level validation only
Aggregate candidates Objects that must change together to maintain a rule Independent CRUD records
Ubiquitous language tension Same word means different things to different teams/features One obvious vocabulary
Complex process modeling Multi-step workflow with state transitions Simple create/read/update

Apply when: At least one condition passes. If none pass, the domain is likely too thin for DDD's tactical vocabulary — keep the domain objects plain and let architecture decide the surrounding structure.

Read the full file on GitHub · 343 lines

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. 9d ago First seen · 343 lines · 0 tokens per session scan A 10d9aa807185

Subscribe to this mod's changes

domain-modeling is a skill published in the GitHub repository elct9620/ai-coding-skills (5 stars, last pushed 4d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 3,450 tokens. 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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