Create ADR Skill

Purpose: Document architectural decisions to provide context for future developers and maintain institutional knowledge about why technical choices were made.

When to Use This Skill

Trigger this skill when:

• Making significant architectural decisions
• Choosing between competing technologies or approaches
• Designing new system components or APIs
• Refactoring that changes system structure
• After implementing a feature that involved design trade-offs

Skip ADR Creation If

• Only minor bug fixes or refactoring
• Documentation or test-only changes
• Configuration tweaks without architectural impact
• Trivial changes with obvious implementation

Workflow

1. Gather Context

Review the implementation to understand:

• What technical decisions were made
• Why this approach was chosen
• What alternatives existed
• What trade-offs were accepted

If reviewing existing code:

git diff main...HEAD
git log --oneline main..HEAD

2. Investigate Further

If the diff doesn't provide enough context:

• Read referenced files/functions
• Check configuration files
• Review related tests
• Look at dependencies added

3. Create the ADR

Location: docs/adr/NNNN-descriptive-title.md

Naming convention:

• Sequential number (0001, 0002, etc.)
• Lowercase with hyphens
• Descriptive but concise

Examples:

• 0001-use-jwt-for-authentication.md
• 0002-adopt-event-sourcing-for-orders.md
• 0003-postgres-over-mysql.md

4. Use the Template

Use the template from ./assets/adr-template.md to structure the document.

Key sections to complete:

• Status: Proposed, Accepted, Deprecated, or Superseded
• Context: The problem or opportunity driving the decision
• Decision: What was decided and the technical approach
• Consequences: Positive, negative, and risks
• Alternatives: What else was considered and why it wasn't chosen

Quality Guidelines

Good ADRs have:

• Specific technical details (not vague descriptions)
• Concrete examples and code snippets where helpful
• Honest assessment of trade-offs
• Links to relevant resources or prior art

Avoid:

• Vague justifications ("it's better")
• Missing alternatives section
• No discussion of consequences
• Too much implementation detail (that belongs in code comments)

Example

User: "Document the decision to use Redis for caching"

Skill activates:

1. Review caching implementation
2. Identify alternatives considered (Memcached, in-memory, etc.)
3. Document trade-offs (complexity vs performance)
4. Create docs/adr/0005-redis-for-application-cache.md

Integration

Works well with:

• Major feature implementations
• System refactoring efforts
• Technology migrations
• API design decisions