domain-modeling

Files (7)

• ADR-FORMAT.md
• GLOSSARY-FORMAT.md
• LICENSE
• SKILL.md
• openai.yaml · agents/
• origin.json
• check-glossary.ts · scripts/

SKILL.md (first lines)

# Domain Modeling

Challenge domain terms against concrete scenarios and code. Record resolved terms in the glossary and qualifying decisions in ADRs.

## File structure

Most repos have a single context:

```
/
├── GLOSSARY.md
├── docs/
│   └── adr/
│       ├── 0001-event-sourced-orders.md
│       └── 0002-postgres-for-write-model.md
└── src/
```

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

```
/
├── GLOSSARY-MAP.md
├── docs/
│   └── adr/                          ← system-wide decisions
├── src/
│   ├── ordering/
│   │   ├── GLOSSARY.md
│   │   └── docs/adr/                 ← context-specific decisions
│   └── billing/
│       ├── GLOSSARY.md
│       └── docs/adr/
```

Create files lazily: only when you have something to write. If no `GLOSSARY.md` exists, create one when the first term is resolved. If no `docs/adr/` exists, create it when the first ADR is needed.

## During the session

### Challenge against the glossary

When the user uses a term that conflicts with the existing language in `GLOSSARY.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. Propose the plainest word that stays unambiguous, as [GLOSSARY-FORMAT.md](./GLOSSARY-FORMAT.md) defines it, and treat a term you coined yourself with the same suspicion as the user's. "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 GLOSSARY.md inline

When a term is resolved, update `GLOSSARY.md` right there. Don't batch these up: capture them as they happen. Use the format in [GLOSSARY-FORMAT.md](./GLOSSARY-FORMAT.md).

`GLOSSARY.md` should be totally devoid of implementation details. Do not treat `GLOSSARY.md` as a spec, a scratch pad, or a repository for implementation decisions. It is a glossary and nothing else.

### Check the language

After you add aliases under `_Avoid_`, run `bun scripts/check-glossary.ts` from the project root, with the path resolved from this skill's directory. It finds `GLOSSARY.md`, the older `CONTEXT.md`, or a map of contexts, and prints each avoided alias in the project's Markdown with its file, line, and the term to use. Change each hit to the glossary term, unless the text quotes the old word on purpose.

When the project has no CI step for it, offer one. The project's CI can't see this plugin, so copy the script into the project with a line naming its source. Run it with `--base origin/<default-branch>` on a full-history checkout, so a change fails only on the aliases it adds.

### Offer ADRs sparingly

Only offer to create an ADR when all three are true:

1. **Hard to reverse**: the cost of changing your mind later is meaningful
2. **Surprising without context**: a future reader will wonder "why did they do it this way?"
3. **The result of a real trade-off**: there were genuine alternatives and you picked one for specific reasons

If any of the three is missing, skip the ADR. Use the format in [ADR-FORMAT.md](./ADR-FORMAT.md).

From Camgineer/cstack, MIT.

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