adr-convention

name	adr-convention
description	Use when creating, reviewing, or referencing architectural decision records — defines the ADR format, three-gate creation threshold, and local/hub flavors

ADR Convention

Three-Gate Threshold

Only create an ADR when ALL THREE gates are true:

1. Hard to reverse — changing this decision later requires significant rework
2. Surprising without context — a future reader would wonder "why did they do it this way?"
3. Real trade-off — genuine alternatives existed with different pros/cons

If any gate fails, the decision is normal engineering — document it in the spec, plan, or code comment instead.

Format

File: docs/decisions/YYYY-MM-DD-<kebab-slug>.md

---
id: ADR-NNN        # Sequential. Scan docs/decisions/*.md for highest existing ID, increment.
date: YYYY-MM-DD
status: accepted   # accepted | superseded
type: technical    # technical | contract | convention | infrastructure | data
epic: EPIC-NNN     # Optional. Link to parent epic if applicable.
repos: [repo-a]    # Hub flavor only. Omit for local decisions.
---

Four required body sections:

# [Decision Title]

## Context
[Why this decision was needed. What problem or constraint triggered it.]

## Decision
[What was decided. Concrete, actionable statements.]

## Alternatives Considered
[What else was evaluated and why it was rejected. Brief — one line per alternative is fine.]

## Consequences
[What follows from this decision. Cross-reference enforcement docs if they exist.]

Hub Variant

Hub agreements (cross-repo decisions) add:

• repos: frontmatter field (required) — which repos are affected
• ## Affected Repos section with per-repo details
• ### Details sub-section under Decision for repo-specific implementation notes
• Default type is contract unless the agreement is a convention or infrastructure decision

Pipeline Integration

Command	Role	Behavior
plan	Active	Three-gate check after plan review; prompt to create ADR or flag for review
feature	Light	Prompt on YAGNI overrides and non-obvious approach decisions
tech-review	Passive	Read existing ADRs; tag findings as ADR candidates; never auto-create
start	Reference	Point to this skill for local ADR format
epic	Reference	Point to this skill for hub ADR format

ID Generation

Scan all docs/decisions/*.md files for id: ADR-NNN in frontmatter. Take the highest number, increment by one. If no ADR files exist, start at ADR-001.

Related

• ADR-001 defines the skill size budget: docs/decisions/2026-04-29-skill-size-budget.md
• ADR-002 defines the domain glossary: docs/decisions/2026-04-29-domain-glossary-convention.md
• ADR-003 defines token mode scope: docs/decisions/2026-04-29-token-mode-scope.md
• skills/skill-authoring/SKILL.md enforces the 100-line budget from ADR-001