Feature Planning

Systematically analyze feature requests and create detailed, actionable implementation plans.

When to Use

• Requests new feature ("add user authentication", "build dashboard")
• Asks for enhancements ("improve performance", "add export")
• Describes complex multi-step changes
• Explicitly asks for planning ("plan how to implement X")
• Provides vague requirements needing clarification

Planning Workflow

1. Understand Requirements

Ask clarifying questions:

• What problem does this solve?
• Who are the users?
• Specific technical constraints?
• What does success look like?

Explore the codebase: Use Task tool with subagent_type='Explore' and thoroughness='medium' to understand:

• Existing architecture and patterns
• Similar features to reference
• Where new code should live
• What will be affected

2. Analyze & Design

Identify components:

• Database changes (models, migrations, schemas)
• Backend logic (API endpoints, business logic, services)
• Frontend changes (UI, state, routing)
• Testing requirements
• Documentation updates

Consider architecture:

• Follow existing patterns (check CLAUDE.md)
• Identify reusable components
• Plan error handling and edge cases
• Consider performance implications
• Think about security and validation

Check dependencies:

• New packages/libraries needed
• Compatibility with existing stack
• Configuration changes required

3. Create Implementation Plan

Break feature into discrete, sequential tasks:

markdown
## Feature: [Feature Name]

### Overview
[Brief description of what will be built and why]

### Architecture Decisions
- [Key decision 1 and rationale]
- [Key decision 2 and rationale]

### Implementation Tasks

#### Task 1: [Component Name]
- **File**: `path/to/file.py:123`
- **Description**: [What needs to be done]
- **Details**:
  - [Specific requirement 1]
  - [Specific requirement 2]
- **Dependencies**: None (or list task numbers)

#### Task 2: [Component Name]
...

### Testing Strategy
- [What types of tests needed]
- [Critical test cases to cover]

### Integration Points
- [How this connects with existing code]
- [Potential impacts on other features]

Include specific references:

• File paths with line numbers (src/utils/auth.py:45)
• Existing patterns to follow
• Relevant documentation

4. Review Plan with User

Confirm:

• Does this match expectations?
• Missing requirements?
• Adjust priorities or approach?
• Ready to proceed?

5. Execute with plan-implementer

Launch plan-implementer agent for each task:

Task tool with:
- subagent_type: 'plan-implementer'
- description: 'Implement [task name]'
- prompt: Detailed task description from plan

Execution strategy:

• Implement sequentially (respect dependencies)
• Verify each task before next
• Adjust plan if issues discovered
• Let test-fixing skill handle failures
• Let git-pushing skill handle commits

Best Practices

Planning:

• Start broad, then specific
• Reference existing code patterns
• Include file paths and line numbers
• Think through edge cases upfront
• Keep tasks focused and atomic

Communication:

• Explain architectural decisions
• Highlight trade-offs and alternatives
• Be explicit about assumptions
• Provide context for future maintainers

Execution:

• Implement one task at a time
• Verify before moving forward
• Keep user informed
• Adapt based on discoveries

Integration

• plan-implementer agent: Receives task specs, implements
• test-fixing skill: Auto-triggered on test failures
• git-pushing skill: Triggered for commits