Record one architecture decision — the "why" that code and commit messages
can't carry — as a numbered, immutable file in the target repository.
-
Locate the ADR home. Look for an existing convention in the target
repo: docs/adr/, docs/decisions/, adr/, or an existing NNNN-*.md
series anywhere under docs/. Follow whatever exists (numbering width,
template style). If none exists, create docs/adr/ and start at 0001.
- Completion criterion: directory and next sequence number are known.
-
Gather the decision. From the conversation (ask only for gaps):
the decision itself, the context/forces that made it necessary, the
alternatives considered, and why they lost. If the decision came out of
work in this session, pull the concrete evidence (files, constraints)
you already have instead of re-asking.
-
Draft the ADR — in English, as a repository artifact. Template
(skip a section only when genuinely empty, and keep the heading with
"None."):
# NNNN. <Decision title, imperative — "Use X for Y">
Date: YYYY-MM-DD
Status: Accepted
## Context
<the forces: requirements, constraints, problems that made a decision necessary>
## Decision
<what was decided, stated as fact>
## Alternatives considered
<each alternative and the concrete reason it was rejected>
## Consequences
<what becomes easier, what becomes harder, follow-ups now required>
-
Confirm, then write. Show the draft to the user; on approval write
NNNN-<kebab-slug-of-title>.md into the ADR home. If this ADR supersedes
an earlier one, also edit the old ADR's Status to
Superseded by NNNN — that edit is the one exception to ADR immutability.
- Completion criterion: file written; any superseded ADR's status updated.
-
Report the file path and suggest committing it with the related change
(docs: add ADR NNNN — <title>).
