Design Architecture

You are helping a developer design the architecture for a feature by exploring multiple approaches.

Progress is saved to .artifacts/{feature-slug}/ for session continuity.

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Goal

Design multiple implementation approaches with different trade-offs and help user select the best one.

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Instructions

Feature context: $ARGUMENTS

Actions

1. Launch 2-3 code-architect agents in parallel with different focuses:

   • Minimal changes: Smallest change, maximum reuse of existing code
   • Clean architecture: Maintainability, elegant abstractions
   • Pragmatic balance: Speed + quality trade-off

2. Review all approaches and form your opinion on which fits best for this specific task

   • Consider: small fix vs large feature, urgency, complexity, team context

3. Present to user:

   • Brief summary of each approach
   • Trade-offs comparison
   • Your recommendation with reasoning
   • Concrete implementation differences

4. Ask user which approach they prefer

Artifact

After user selects approach, create design.md:

# {Feature Name} - Design

## Chosen Approach
{Name of chosen approach}

## Rationale
{Why this approach was selected}

## Approaches Considered

### Approach A: {Name}
- **Summary**: {brief description}
- **Pros**: {list}
- **Cons**: {list}
- **Effort**: {estimate}

### Approach B: {Name}
- **Summary**: {brief description}
- **Pros**: {list}
- **Cons**: {list}
- **Effort**: {estimate}

## Architecture Overview
{High-level description of the solution}

## Component Design
### {Component 1}
- Purpose: {what it does}
- Interface: {public API}
- Dependencies: {what it uses}

## Data Flow
{How data moves through the system}

## Integration Points
- {Where this connects to existing code}

## Risks and Mitigations
| Risk | Mitigation |
|------|------------|
| {risk} | {mitigation} |

Git Commits

Multiple as phase progresses:

• After presenting options: docs({feature-slug}): document architecture options
• After user selects approach: docs({feature-slug}): select {approach-name} approach

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Next Steps

After architecture is designed, guide the user to use:

• /harness:implement-feature to build the feature