ConnorGriffin 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.)
Two files, two different contents: sharpened glossary terms go to
CONTEXT.md; decisions that constrain architecture or behaviour go to the
repository's resolved ADR home. With active OpenSpec, that is the change's
design.md; otherwise follow references/ADR-FORMAT.md. Don't
conflate them — a term is not a decision, and a decision is not a definition.
File structure
Most repos have a single context (the docs/adr/ trees below illustrate a repo
with no existing decision record; resolve the ADR's home first, per
references/ADR-FORMAT.md):
/
├── CONTEXT.md
├── docs/
│ └── adr/
│ ├── adr-42-event-sourced-orders.md
│ └── adr-57-postgres-for-write-model.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
├── docs/
│ └── adr/ ← system-wide decisions
├── src/
│ ├── ordering/
│ │ ├── CONTEXT.md
│ │ └── docs/adr/ ← context-specific decisions
│ └── billing/
│ ├── CONTEXT.md
│ └── docs/adr/
Create files lazily — only when you have something to write. If no
CONTEXT.md exists, create one when the first term is resolved. An ADR goes
wherever the repo already records decisions (references/ADR-FORMAT.md),
and a new docs/adr/ is created only when that resolves to docs/adr/.
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?"
When the model touches module shape — interfaces, seams, adapters — use the
codebase-design skill's vocabulary rather than inventing your own terms for
architecture; keep CONTEXT.md itself limited to domain language (see
references/CONTEXT-FORMAT.md).
Update CONTEXT.md inline
When a term is resolved, update CONTEXT.md right there. Don't batch these
up — capture them as they happen. Use the format in
references/CONTEXT-FORMAT.md.
CONTEXT.md should be totally devoid of implementation details. Do not treat
CONTEXT.md as a spec, a scratch pad, or a repository for implementation
decisions. It is a glossary and nothing else.
Offer ADRs sparingly
Only offer to create an ADR when all three are true:
- Hard to reverse — the cost of changing your mind later is meaningful
- Surprising without context — a future reader will wonder "why did they do it this way?"
- 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 references/ADR-FORMAT.md.