First Project

This guide walks you through creating a simple todo management feature using SDD Tool.

1. Initialize Project

mkdir todo-app
cd todo-app
npm init -y
sdd init

2. Start Claude Code

claude

3. Write Constitution

Define the core principles of your project:

/sdd.constitution React-based todo management app

The AI will help you write the project principles through conversation.

Example Constitution

# Todo App Constitution

## Core Principles
- User experience is the top priority
- Must work offline

## Technical Principles
- Use React + TypeScript
- Store data in local storage

## Forbidden
- No external API dependencies

4. Write Feature Spec

/sdd.spec Add todo feature

The AI will help you write the spec through conversation.

Example Spec

---
id: add-todo
title: "Add Todo"
status: draft
---

# Add Todo

## Requirements

### REQ-01: Todo Input
- The system SHALL support todo text input
- Empty text SHALL be rejected

## Scenarios

### Scenario 1: Successful Todo Addition
- **GIVEN** the user is on the todo input form
- **WHEN** they enter "Buy milk" and click the add button
- **THEN** "Buy milk" is added to the todo list

5. Implementation Plan

/sdd.plan

The AI will create a technical implementation plan.

6. Task Breakdown

/sdd.tasks

The AI will break down the work into executable task units.

7. Tool Check

/sdd.prepare

Verify and create necessary subagents and skills.

8. Implementation

/sdd.implement

The AI guides sequential TDD-style implementation:

1. Write tests
2. Implement code
3. Verify tests pass
4. Move to next task

9. Validation

/sdd.validate

Validate that the spec is correctly written.

Complete!

Your first SDD-based feature is finished.

Next Steps

• Understanding Workflow
• Best Practices