create-adr

name	create-adr
description	Record an architecture/design decision as an ADR (Architecture Decision Record) in the target repository's docs/adr/. Use when the user wants to document a design decision, its alternatives and consequences, or says "record this decision" / "write an ADR".
allowed-tools	Read Glob Grep Write Bash(git *)

Create ADR

Record one architecture decision — the "why" that code and commit messages can't carry — as a numbered, immutable file in the target repository.

An ADR records a decision made, not a proposal under discussion. If the decision isn't settled yet, help settle it in conversation first; write the ADR after.

Steps

1. 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.

2. 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.

3. 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>
   

4. 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 If this ADR supersedes an earlier one, also edit the old ADR's Status to Superseded by NNNN — that edit is the one exception to ADR immutability.

   • Completion criterion: file written; any superseded ADR's status updated.

5. Report the file path and suggest committing it with the related change (docs: add ADR NNNN — <title>).

Failure modes

• The "decision" is still an open question → don't write a Status: Accepted ADR for it; either help decide first or, if the user wants the open state recorded, use Status: Proposed and say so.
• Two decisions in one request → two ADRs; one record per decision.