architecture-decision-records

name	architecture-decision-records
description	Manages the ADR (Architecture Decision Record) registry. Use when recording tech-stack choices, design patterns, or infrastructure decisions with context, alternatives, and rationale. Supports listing, searching, or creating formal ADR documents.
context	fork
agent	technical-director
allowed-tools	Read, Glob, Grep, Write, Bash
argument-hint	[title or decision topic]
user-invocable	true
effort	4
when_to_use	When needing to make a formal technology decision and record the underlying reasoning in docs/architecture/.

Architecture Decision Records

Workflow Protocol

1. Determine the next ADR number by scanning docs/architecture/ for existing ADRs.
2. Gather context by reading related code and existing ADRs.
3. Guide the user through the decision by asking clarifying questions if the title alone is insufficient.
4. Generate the ADR following the template below.
5. Save the ADR to docs/architecture/adr-[NNNN]-[slug].md.
6. Update the Index Table in docs/architecture/README.md or docs/technical/DECISIONS.md.

When to write an ADR vs skip

Write ADR	Skip ADR
New framework/database adoption	Minor version upgrades
API design patterns	Bug fixes
Security architecture	Implementation details
Integration patterns	Routine maintenance

ADR lifecycle

Proposed → Accepted → Deprecated → Superseded
              ↓
           Rejected

Template (MADR format — use this)

# ADR-NNNN: [Title]

## Status
Accepted | Proposed | Deprecated | Superseded by ADR-XXXX

## Context
[Problem statement, current situation, constraints, scale]

## Decision Drivers
- [Must/Should/Could requirement]

## Considered Options
### Option 1: [Name] — [one-line summary]
Pros: ... | Cons: ...

### Option 2: [Name]
Pros: ... | Cons: ...

## Decision
We will use **[Option N]** because [key rationale].

## Consequences
**Positive:** ...
**Negative:** ...
**Risks:** ... Mitigation: ...

## Related ADRs
- ADR-XXXX: [relationship]

Quick examples

Lightweight ADR (for clear-cut decisions):

# ADR-0012: Adopt TypeScript for Frontend

**Status**: Accepted | **Date**: 2024-01-15 | **Deciders**: @alice, @bob

## Context
50+ React components with prop-type-mismatch bugs. PropTypes are runtime-only.

## Decision
TypeScript for all new frontend code. Migrate incrementally with `allowJs: true`.

## Consequences
Good: Compile-time errors, better IDE support.
Bad: Learning curve, initial slowdown.

Y-Statement (for concise formal record):

In the context of **building a microservices architecture**,
facing **need for centralized auth and rate limiting**,
we decided for **Kong Gateway**
and against **AWS API Gateway and custom Nginx**,
to achieve **vendor independence and plugin extensibility**,
accepting **we manage Kong infrastructure ourselves**.

File structure

docs/adr/
├── README.md              # Index table
├── template.md
├── 0001-use-postgresql.md
└── 0003-mongodb-deprecated.md  # [SUPERSEDED by 0020]

Index table (maintain in README.md)

ADR	Title	Status	Date
0001	Use PostgreSQL	Accepted	2024-01-10
0003	MongoDB for profiles	Deprecated	2023-06-15

Key rules

• Never modify accepted ADRs — write a new one to supersede
• Write early — before implementation starts, not after
• Max 1-2 pages — if longer, decision scope is too broad
• State real cons — an ADR without honest tradeoffs has no value
• Update status — mark deprecated when superseded; link the new ADR

Automation

# With adr-tools
adr init docs/adr
adr new "Use PostgreSQL as Primary Database"
adr new -s 3 "Deprecate MongoDB"   # -s supersedes ADR 3
adr generate toc > docs/adr/README.md