CodexSpec

CodexSpec is a toolkit that guides software development through Requirements-First Spec-Driven Development (SDD), where confirmed requirements take priority and nothing becomes binding until explicitly approved. Instead of moving directly to code, teams define what to build and why before deciding how. It integrates with Claude Code via slash commands and provides persistent requirement capture, automatic quality reviews, and cross-artifact consistency checks.

The toolkit emphasizes team collaboration with multi-language support, constitution-based development principles, and traceable task breakdowns. It preserves requirement coverage through conditional test-driven development and helps teams recover from interruptions by persisting specifications and plans. The maker indicates it was built with Claude Code.