# Principle Model The Domain

> Model the Domain

- Skill: `theonlyfusioncube/principle-model-the-domain` (Agent Skill)
- Install (CLI): `npx skillmds@latest add theonlyfusioncube/principle-model-the-domain`
- Raw SKILL.md: https://api.skillmd.com/api/skills/theonlyfusioncube/principle-model-the-domain/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: TheOnlyFusionCube (https://skillmd.com/u/theonlyfusioncube)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/theonlyfusioncube/principle-model-the-domain

---

# Model the Domain

## Trigger

When stateful logic accumulates branches or repeated shape assumptions.

## Rule

Encode the domain in the right structure: state machine, typed model, table, registry, reducer, boundary, or collection instead of scattered conditionals.

## Application

1. Name the concrete decision this principle changes.
2. Apply the rule to that decision, not as a decorative citation.
3. Prefer evidence from the current repository/runtime over generic preference.
4. If the principle conflicts with an explicit user constraint, keep the constraint and state the tradeoff.