Sdd

Spec-Driven Development (SDD)

*Structure for AI-assisted development*

AI coding assistants are powerful but chaotic. You prompt, you get code, but then what? No documentation of decisions, no way to verify the code matches what you needed, and a codebase that's impossible to explain to teammates.

SDD brings structure to AI-assisted development. Every change starts with a spec, gets broken into a plan, and ends with verified implementation. Specialized agents handle each concern instead of one AI doing everything poorly.

Installation

Quick Start

Get started with the tutorial →

How It Works

Specs Are the Source of Truth

Every change lives in a markdown specification before it lives in code:

Specs include frontmatter metadata, acceptance criteria in Given/When/Then format, and references to domain concepts.

Four Change Types

Specialized Agents

Instead of one general-purpose AI, SDD uses 7 specialized agents:

Commands

Reducing Permission Prompts

SDD commands create many files. To reduce permission prompts, add this to your .claude/settings.local.json:

See Permissions Setup for full configuration options.

Documentation

- Getting Started - First project tutorial
- Workflows - Feature, bugfix, and refactor workflows
- Commands - Full command reference
- Agents - What each agent does
- Components - Component types reference
- Configuration Guide - Config system details
- Permissions Setup - Reduce permission prompts

Project Structure

When you run /sdd I want to initialize a new project, you get:

Architectural Patterns

- CMDO Backend - Controller Model DAL Operator with strict layer separation
- MVVM Frontend - Model-View-ViewModel with TanStack ecosystem
- Contract-First API - OpenAPI specs generate TypeScript types
- Immutability Enforced - readonly…