OpenSpec is an open-source, specification-driven development framework designed for teams and individuals building software with AI coding assistants such as Cursor, Claude Code, GitHub Copilot and Codex. Rather than relying on prompts and chat history alone, OpenSpec introduces a lightweight process for documenting what a system should do before code is written.
At its core, OpenSpec creates a persistent layer of project knowledge that lives alongside the codebase. Proposed changes are captured as specifications, design decisions, implementation tasks and requirement updates, giving both humans and AI agents a shared understanding of intent. This helps reduce the common problem of AI tools losing context, misunderstanding requirements, or generating solutions that drift away from the original objective.
Unlike traditional specification approaches, OpenSpec is intentionally lightweight and designed for iterative development. It is particularly useful for existing products and codebases where understanding how a system should behave is often more valuable than understanding how it is currently implemented.
For designers, product teams and developers working with AI-assisted workflows, OpenSpec provides a practical way to move from vague prompts and conversations toward documented decisions, traceable requirements and more predictable outcomes. It effectively acts as a bridge between strategy, planning and implementation, ensuring that intent survives long after a chat session ends.