# Domain Modeling

Build and sharpen a project's domain model.

- Repository: https://github.com/windmill-labs/windmill (18352 stars)
- Category: Engineering
- License: see repository
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add windmill-labs/windmill --skill domain-modeling -g -a claude-code -y`
Codex: `npx skills add windmill-labs/windmill --skill domain-modeling -g -a codex -y`
Cursor: `npx skills add windmill-labs/windmill --skill domain-modeling -g -a cursor -y`
Gemini CLI: `npx skills add windmill-labs/windmill --skill domain-modeling -g -a gemini-cli -y`

## Description

Build and sharpen a project's domain model. Use when the user wants to pin down domain terminology or a ubiquitous language, or when another skill needs to maintain the domain model.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Domain Modeling

Actively build and sharpen the project's domain model as you design. This is the *active* discipline, challenging terms, inventing edge-case scenarios, and writing the glossary and decisions down the moment they crystallise. (Merely *reading* `CONTEXT.md` for vocabulary is not this skill, that's a one-line habit any skill can do. This skill is for when you're changing the model, not just consuming it.)

## File structure

Most repos have a single context:

```
/
├── CONTEXT.md
└── src/
```

If a `CONTEXT-MAP.md` exists at the root, the repo has multiple contexts. The map points to where each one lives:

```
/
├── CONTEXT-MAP.md
└── src/
    ├── ordering/
    │   └── CONTEXT.md
    └── billing/
        └── CONTEXT.md
```

Create files lazily, only when you have something to write. If no `CONTEXT.md` exists, create one when the first term is resolved.

## During the session

### Challenge against the glossary

When the user uses a term that conflicts with the existing language in `CONTEXT.md`, call it out immediately. "Your glossary defines 'cancellation' as X, but you seem to mean Y, which is it?"

### Sharpen fuzzy language

When the user uses vague or overloaded terms, propose a precise canonical term. "You're saying 'account', do you mean the Customer or the User? Those are different things."

### Discuss concrete scenarios

When domain relationships are being discussed, stress-test them with specific scenarios. Invent scenarios that probe edge cases and force the user to be precise about the boundaries between concepts.

### Cross-reference with code

When the user states how something works, check whether the code agrees. If you find a contradiction, surface it: "Your code cancels entire Orders, but you just said partial cancellation is possible, which is right?"

### Update CONTEXT.md inline

The rest: https://github.com/windmill-labs/windmill/blob/HEAD/.agents/skills/domain-modeling/SKILL.md