SpecDD is an open-source framework for specification-driven development in software, infrastructure, automation, and documentation projects. It provides a shared source of truth for intent, requirements, boundaries, and completion criteria for both humans and AI agents.
Key features:
- Uses small, local, human-readable
.sddfiles that live beside the code they describe - Documents intent, architecture, behavior, boundaries, and implementation tasks
- Works with all major file-aware coding agents (OpenAI Codex, Claude Code, GitHub Copilot, Cursor, etc.)
- Language-agnostic: works with JavaScript, TypeScript, Python, Go, PHP, Java, C#, Rust, Ruby, and more
- Supports both greenfield and existing projects
- Includes a CLI tool for setup and framework updates
- Uses path-based resolution and constraint inheritance
- Provides a universal spec language with sections for purpose, ownership, requirements, contracts, and tasks
Use cases:
- Breaking large projects into small implementation areas
- Giving AI agents durable project context inside the repository
- Structuring design documents and preserving architecture boundaries
- Capturing business behavior near implementation
- Improving consistency between code, tests, and intent
- Reducing correction loops in AI-assisted development
