domain-modeling Skill (mattpocock/skills) for Claude Code: What It Does and How to Install It

Makes Claude build and sharpen your project's vocabulary as you design, writing GLOSSARY.md and decision records the moment a term is settled.

Installs: 919.8K; on skills.sh
Stars: 309.2K; on GitHub
Files: 3; besides SKILL.md
Updated: Nov 2026; last repo commit

domain-modeling makes Claude challenge your words while you work. If you say "account" and your glossary says Customer and User are different, it asks which you mean. It invents edge-case scenarios, checks whether your code agrees with what you just said, and updates GLOSSARY.md right away.

It starts when you discuss terminology, edit a glossary or record an architecture decision (ADR). It creates files only when it has something to write, and offers an ADR only when the choice is hard to reverse, surprising and a real trade-off. It writes markdown files in your repo, runs no scripts and needs no API key.

Good for

Developers naming things in a new or messy codebase
Teams that want a shared glossary the AI also follows
Architects who record decisions as ADRs

Install domain-modeling

Claude Code

Copy this prompt.

Install the domain-modeling skill in Claude Code. Run this command:

npx skills add https://github.com/mattpocock/skills --skill domain-modeling

Then check that it loaded and tell me how to use it.

2
Paste it into Claude Code. It shows the change and asks before running it.

Requires Node.js.

From its listing on skills.sh. Source.

What's in the skill

When it loads

Build and sharpen a project's domain model. Use when discussing codebase terminology, writing or editing a GLOSSARY.md, or recording or editing an ADR.

Sections in SKILL.md

File structure
During the session
Challenge against the glossary
Sharpen fuzzy language
Discuss concrete scenarios
Cross-reference with code
Update GLOSSARY.md inline
Offer ADRs sparingly

Key facts

Author: Matt Pocock (mattpocock/skills)
License: MIT
Installs on skills.sh: 919,836 (Nov 2, 2026)
GitHub stars: 309,237 (whole repo, Nov 2, 2026)
Last commit: Nov 1, 2026 (repo)
Files it bundles: SKILL.md, ADR-FORMAT.md, GLOSSARY-FORMAT.md, agents/openai.yaml
Starts: Can start when your request matches its description

What it includes

Calls out terms that conflict with GLOSSARY.md
Read · Challenge against the glossary
Proposes one precise term for vague or overloaded words
Sharpen fuzzy language
Invents edge cases to force exact boundaries between concepts
Discuss concrete scenarios
Checks whether the code agrees with what you said
Files · Cross-reference with code
Writes each term as soon as it is resolved, using GLOSSARY-FORMAT.md
Write · Update GLOSSARY.md inline
Suggests a record only for hard-to-reverse, surprising, real trade-offs (ADR-FORMAT.md)
Write · Offer ADRs sparingly
One GLOSSARY.md and docs/adr, or a GLOSSARY-MAP.md pointing to per-context glossaries
Files · Single or multi-context layout

From the official docs

Questions

What does the domain-modeling skill do?

It builds your project's domain language while you design. It challenges terms, proposes precise ones, tests them against scenarios and your code, and writes them into GLOSSARY.md as you go.

How do I install it?

Use the install box at the top of this page. triage also calls this skill, so install the whole set if you use triage.

What is a GLOSSARY.md and an ADR?

GLOSSARY.md lists your project's terms and what they mean. An ADR is a short record of a design decision and why you made it. The skill says the glossary holds no implementation details.

When does it write an ADR?

Only when the decision is hard to reverse, surprising without context and a real trade-off. If any of the three is missing, it skips it.

Does it need an API key or scripts?

No. It reads your code and writes markdown files. Two bundled guides define the glossary and ADR formats.

Is it safe?

It creates and edits markdown files in your repo, so review changes in git. skills.sh audits: Gen Agent Trust Hub pass, Socket pass, Snyk pass.

Information

updated Nov 2, 2026

Repository: mattpocock/skills
Folder: skills/engineering/domain-modeling

mattpocock/skills skills.sh

Sources

Docs, issue trackers and discussions this page is built from.

Show all 3

domain-modeling SKILL.md · github.com
skills.sh listing and audits · skills.sh
mattpocock/skills · github.com