architecture-decision-record

Architecture Decision Records

Architecture Decision Records (ADRs) are lightweight documents that capture important architectural decisions along with their context and consequences. This skill provides templates, examples, and best practices for creating and maintaining ADRs in your projects.

Overview

• Making significant technology choices (databases, frameworks, cloud providers)
• Designing system architecture or major components
• Establishing patterns or conventions for the team
• Evaluating trade-offs between multiple approaches
• Documenting decisions that will impact future development

Why ADRs Matter

ADRs serve as architectural memory for your team:

• Context Preservation: Capture why decisions were made, not just what was decided
• Onboarding: Help new team members understand architectural rationale
• Prevent Revisiting: Avoid endless debates about settled decisions
• Track Evolution: See how architecture evolved over time
• Accountability: Clear ownership and decision timeline

ADR Format (Nygard Template)

Each ADR should follow this structure:

1. Title

Format: ADR-####: [Decision Title] Example: ADR-0001: Adopt Microservices Architecture

2. Status

Current state of the decision:

• Proposed: Under consideration
• Accepted: Decision approved and being implemented
• Superseded: Replaced by a later decision (reference ADR number)
• Deprecated: No longer recommended but not yet replaced
• Rejected: Considered but not adopted (document why)

3. Context

What to include:

• Problem statement or opportunity
• Business/technical constraints
• Stakeholder requirements
• Current state of the system
• Forces at play (conflicting concerns)

4. Decision

What to include:

• The choice being made
• Key principles or patterns to follow
• What will change as a result
• Who is responsible for implementation

Be specific and actionable:

• ✅ "We will adopt microservices architecture using Node.js with Express"
• ❌ "We will consider using microservices"

5. Consequences

What to include:

• Positive outcomes (benefits)
• Negative outcomes (costs, risks, trade-offs)
• Neutral outcomes (things that change but aren't clearly better/worse)

6. Alternatives Considered

Document at least 2 alternatives:

For each alternative, explain:

• What it was
• Why it was considered
• Why it was not chosen

7. References (Optional)

Links to relevant resources:

• Meeting notes or discussion threads
• Related ADRs
• External research or articles
• Proof of concept implementations

ADR Lifecycle

Proposed → Accepted → [Implemented] → (Eventually) Superseded/Deprecated
          ↓
      Rejected

Best Practices

1. Keep ADRs Immutable

Once accepted, don't edit ADRs. Create new ADRs that supersede old ones.

• ✅ Create ADR-0015 that supersedes ADR-0003
• ❌ Update ADR-0003 with new decisions

2. Write in Present Tense

ADRs are historical records written as if the decision is being made now.

• ✅ "We will adopt microservices"
• ❌ "We adopted microservices"

3. Focus on 'Why', Not 'How'

ADRs capture decisions, not implementation details.

• ✅ "We chose PostgreSQL for relational consistency"
• ❌ "Configure PostgreSQL with these specific settings..."

4. Review ADRs as Team

Get input from relevant stakeholders before accepting.

• Architects: Technical viability
• Developers: Implementation feasibility
• Product: Business alignment
• DevOps: Operational concerns

5. Number Sequentially

Use 4-digit zero-padded numbers: ADR-0001, ADR-0002, etc. Maintain a single sequence even with multiple projects.

6. Store in Git

Keep ADRs in version control alongside code:

• Location: /docs/adr/ or /architecture/decisions/
• Format: Markdown for easy reading
• Branch: Same branch as implementation

Quick Start Checklist

Option 1: Use Script-Enhanced Generator (Recommended)

• [ ] Run /create-adr [number] [title] to generate ADR with auto-filled context
• [ ] ADR number, date, and author are auto-populated
• [ ] Review and fill in decision details
• [ ] Set Status to "Proposed" and review with team

Option 2: Use Static Template

• [ ] Copy ADR template from assets/adr-template.md
• [ ] Assign next sequential number (check existing ADRs)
• [ ] Fill in Context: problem, constraints, requirements
• [ ] Document Decision: what, why, how, who
• [ ] List Consequences: positive, negative, neutral
• [ ] Describe at least 2 Alternatives: what, pros/cons, why not chosen
• [ ] Add References: discussions, research, related ADRs
• [ ] Set Status to "Proposed"
• [ ] Review with team
• [ ] Update Status to "Accepted" after approval
• [ ] Link ADR in implementation PR
• [ ] Update Status to "Implemented" after deployment

Available Scripts

• scripts/create-adr.md - Dynamic ADR generator with auto-filled context
• Auto-fills: ADR number, date, author, total ADRs count
• Usage: /create-adr [number] [title]
• Uses $ARGUMENTS and !command for dynamic context

• assets/adr-template.md - Static template for manual use

Rules Quick Reference

Common Pitfalls to Avoid

❌ Too Technical: "We'll use Kubernetes with these 50 YAML configs..." ✅ Right Level: "We'll use Kubernetes for container orchestration because..."

❌ Too Vague: "We'll use a better database" ✅ Specific: "We'll use PostgreSQL 15+ for transactional data because..."

❌ No Alternatives: Only documenting the chosen solution ✅ Comparative: Document why alternatives weren't chosen

❌ Missing Consequences: Only listing benefits ✅ Balanced: Honest about costs and trade-offs

❌ No Context: "We decided to use Redis" ✅ Contextual: "Given our 1M+ concurrent users and sub-50ms latency requirement..."

Related Skills

• ork:api-design: Use when designing APIs referenced in ADRs
• ork:database-patterns: Use when ADR involves database choices
• security-checklist: Consult when ADR has security implications

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Skill Version: 2.0.0 Last Updated: 2026-01-08 Maintained by: AI Agent Hub Team

Capability Details

adr-creation

Keywords: adr, architecture decision, decision record, document decision Solves:

• How do I document an architectural decision?
• Create an ADR
• Architecture decision template

adr-best-practices

Keywords: when to write adr, adr lifecycle, adr workflow, adr process, adr review, quantify impact Solves:

• When should I write an ADR?
• How do I manage ADR lifecycle?
• What's the ADR review process?
• How to quantify decision impact?
• ADR anti-patterns to avoid
• Link related ADRs

tradeoff-analysis

Keywords: tradeoff, pros cons, alternatives, comparison, evaluate options Solves:

• How do I analyze tradeoffs?
• Compare architectural options
• Document alternatives considered

consequences

Keywords: consequence, impact, risk, benefit, outcome Solves:

• What are the consequences of this decision?
• Document decision impact
• Risk and benefit analysis