kensaurus Domain Modeling
A shared language between user, agent, and codebase pays off every session: consistent naming, fewer tokens spent describing concepts, and a codebase the agent can navigate by vocabulary. Adapted from mattpocock/skills (MIT).
This is the active discipline — challenging terms, inventing edge-case
scenarios, and writing the glossary and decisions down the moment they
crystallize. Merely reading CONTEXT.md for vocabulary is a one-line habit any
skill can do; this skill is for changing the model, not consuming it.
File structure
/
├── CONTEXT.md ← the glossary (create on first resolved term)
├── docs/adr/ ← architectural decision records
│ └── 0001-<dash-case-title>.md
└── src/
Create files lazily — only when there is something to write. CONTEXT.md is a
glossary and nothing else: no implementation details, no spec content, no
scratch notes.
CONTEXT.md entry format
**<Canonical term>**:
<One- or two-line definition in domain language, not implementation language.>
_Avoid_: <rejected synonyms, comma-separated>
During the session
- Challenge against the glossary. When the user uses a term that conflicts
with
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 a term is vague or overloaded, propose a precise canonical term: "You're saying 'account' — do you mean the Customer or the User?"
- Stress-test with concrete scenarios. Invent edge-case scenarios that force precision about the boundaries between concepts.
- Cross-reference with code. When the user states how something works, check whether the code agrees, and surface contradictions.
- Update
CONTEXT.mdinline. Capture each resolved term the moment it is resolved — don't batch.
ADRs — offer sparingly
Only offer to create an ADR when all three hold:
- Hard to reverse — changing your mind later costs something real.
- Surprising without context — a future reader will ask "why this way?"
- A real trade-off — genuine alternatives existed and one was picked for specific reasons.
ADR body: Status, Context (the forces), Decision (what and why), Consequences
(what becomes easier/harder). Number sequentially in docs/adr/.
Related: grilling (use both in one session to interview and capture the
language), design-prd, docs-coauthor.