---
description: "Create numbered ADR documenting architectural decision"
argument-hint: "<title> [variant]"
allowed-tools: ["Read", "Write", "Grep", "Glob"]
---

# Create Architecture Decision Record

Create a new Architecture Decision Record (ADR) documenting an architectural decision.

## Your Task

1. **Parse Arguments**:
   - Extract decision title from `$ARGUMENTS`
   - Check for variant keyword: `lightweight`, `full`, or `madr`
   - If variant found, remove it from title
   - Default variant: `nygard` (Nygard style)

2. **Determine ADR Number**:
   - Scan `docs/adr/` directory
   - Find highest existing ADR number (format: `XXXX-*`)
   - Increment by 1
   - If no ADRs exist, start with `0001`
   - Format as 4-digit padded number (e.g., `0001`, `0023`)

3. **Sanitize Title for Filename**:
   - Convert title to kebab-case
   - Remove special characters
   - Lowercase all letters
   - Example: "Use Redis for Caching" → `use-redis-for-caching`

4. **Gather Context**:
   - Search codebase for relevant information about the decision topic
   - Look for related code, configs, or documentation
   - Understand current state and alternatives
   - Keep context concise but informative

5. **Load Template**:
   - Template location: `commands/docs/templates/adr/`
   - Select based on variant:
     - `nygard` → `nygard.md` (default)
     - `lightweight` → `lightweight.md`
     - `full` → `full.md`
     - `madr` → `madr.md`

6. **Populate Template**:
   Replace placeholders:
   - `{{ADR_NUMBER}}` - 4-digit number
   - `{{ADR_TITLE}}` - Original title (Title Case)
   - `{{DATE}}` - Current date (YYYY-MM-DD)
   - `{{CONTEXT}}` - Gathered context from codebase
   - `{{PROJECT_NAME}}` - Git repo or directory name

7. **Create ADR File**:
   - Filename: `docs/adr/XXXX-kebab-case-title.md`
   - Ensure `docs/adr/` directory exists
   - Write populated content
   - Set initial status to "Proposed"

8. **Report Creation**:
   - Show ADR number and title
   - Display file path
   - Provide next steps

## Template Variants

### Nygard Style (Default)
Michael Nygard's ADR format - concise and focused.

**Sections:**
- Title with number
- Status
- Context
- Decision
- Consequences

**Use when:** Most decisions, balanced detail

### Lightweight
Minimal ADR for quick decisions.

**Sections:**
- Title with number
- Status
- Decision
- Rationale

**Use when:** Simple, straightforward decisions

### Full
Comprehensive ADR with detailed sections.

**Sections:**
- Title with number
- Status
- Context
- Decision Drivers
- Considered Options
- Decision
- Consequences (Positive, Negative, Neutral)
- Pros and Cons
- Related Decisions
- References

**Use when:** Complex, high-impact decisions

### MADR
Markdown Architectural Decision Records format.

**Sections:**
- Title with number
- Status
- Context and Problem Statement
- Decision Drivers
- Considered Options
- Decision Outcome
- Consequences

**Use when:** Following MADR standard

## Usage

Basic ADR creation (uses Nygard template):
```
/docs:adr "Database Migration Strategy"
/docs:adr "API Authentication Approach"
/docs:adr "Microservices Communication Pattern"
```

With template variant override:
```
/docs:adr lightweight "Use Redis for Session Storage"
/docs:adr full "Adopt Event-Driven Architecture"
/docs:adr madr "Select Database Technology"
```

## ADR Numbering

- **First ADR**: `0001-record-architecture-decisions.md` (meta-ADR)
- **Subsequent ADRs**: Auto-incremented (0002, 0003, etc.)
- **Format**: `XXXX-kebab-case-title.md`

## ADR Status Lifecycle

Update status in the ADR as the decision progresses:

1. **Proposed** - Initial proposal (default)
2. **Accepted** - Decision approved
3. **Deprecated** - No longer recommended
4. **Superseded** - Replaced by another ADR

## Context Gathering Examples

```bash
# For database decisions
!`find . -name "*.sql" -o -name "*models.py" -o -name "*schema.prisma" | head -10`

# For API decisions
!`grep -r "router\|endpoint\|api" --include="*.py" --include="*.ts" --include="*.js" . | head -20`

# For architecture decisions
!`find . -name "docker-compose.yml" -o -name "*.config.js" -o -name "*.config.ts" | head -10`
```

## Important Notes

- **One Decision per ADR**: Keep focused on a single decision
- **Context Matters**: Include "why" even if it seems obvious
- **Link Related ADRs**: Reference superseded or related decisions
- **Early Documentation**: Create ADRs early in decision process
- **Imperative Language**: Use "we will" not "we should"
- **Status Updates**: Update status as decision progresses

## Example Output

```
Architecture Decision Record Created ✓

ADR-0006: Use Redis for Session Storage
File: docs/adr/0006-use-redis-for-session-storage.md
Status: Proposed
Template: Nygard Style

Next Steps:
  1. Review and refine the decision context
  2. Fill in consequences (positive/negative)
  3. Discuss with team
  4. Update status to "Accepted" when approved
  5. Reference this ADR in related code/docs
```

## When to Create ADRs

Create an ADR when making:
- Technology stack decisions
- Architecture pattern choices
- Database or storage decisions
- API design choices
- Security architecture decisions
- Deployment strategy decisions
- Major library/framework selections
- Cross-cutting concerns (logging, caching, etc.)

## Best Practices

- **Create early**: Document decisions before implementation
- **Be honest**: Document the real reasons, not ideal reasons
- **Include alternatives**: Show what was considered
- **Accept trade-offs**: Acknowledge negative consequences
- **Link to code**: Reference implementation in the ADR
- **Review regularly**: Revisit ADRs during retrospectives
- **Update status**: Keep status current as decisions evolve

---

**Template Location**: `commands/docs/templates/adr/`
**Output Directory**: `docs/adr/`