OpenSpec is a lightweight spec-driven development (SDD) framework designed specifically to align humans and AI coding assistants before any code gets written. Think of it as "version control for intent" - you create explicit, reviewable specifications that guide AI assistants to build what you actually want, not what they infer from chat history.
OpenSpec distinguishes itself from alternatives (GitHub's Spec Kit, AWS Kiro) through two key principles:
1. Brownfield-First Design Most SDD tools assume greenfield (0→1) development. OpenSpec excels at existing codebase modification (1→n), especially when changes span multiple specifications. The folder structure reflects this: