What is OpenSpec and how does it help with AI coding?

OpenSpec is a tool for Spec-Driven Development (SDD). It requires documenting functionality before coding, which provides AI assistants like Claude with a clear source of truth, drastically reducing errors and hallucinations.

What are the core requirements for a specification document?

Documents must use Delta sections (ADDED/MODIFIED/REMOVED), include mandatory keywords (MUST/SHALL/SHOULD), and define Gherkin-style scenarios (WHEN/THEN/AND) for validation.

Can OpenSpec be used on existing projects?

Yes, OpenSpec is specifically designed for 'brownfield' projects. Its dual-folder system allows you to manage new changes in a separate directory before merging them into the main specifications.

Does this support multi-agent workflows?

Yes, the OpenSpec skill is designed to manage complex tasks by allowing a main agent to orchestrate multiple sub-agents to perform code exploration, modification, and reporting in parallel.

OpenSpec SDD Assistant

Name: OpenSpec SDD Assistant
Author: ruan-cat

byruan-cat

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Productivity & Workflow

Implements specification-driven development to align human intent with AI execution through structured documentation and validation.

OpenSpec is a specialized tool designed to facilitate specification-driven development (SDD) when working with AI coding assistants. It eliminates AI hallucinations and unpredictable outputs by enforcing a rigorous workflow: documenting requirements in a 'specs/' source-of-truth and managing incremental updates via a 'changes/' folder. By using strict Gherkin scenarios and mandatory requirement keywords (MUST/SHALL), it ensures that AI agents follow precise blueprints, making it ideal for team collaboration and long-term maintenance of complex codebases.

Key Features

01Slash command integration for Claude Code, Cursor, and other AI tools

021 GitHub stars

03Strict format validation for requirements using MUST/SHALL and Gherkin scenarios

04Automated initialization of project context and AI-compatible instructions

05Dual-folder model for separating established specs from proposed changes

06Multi-agent task orchestration for large-scale code implementation

Use Cases

01Creating living documentation that automatically syncs with codebase evolution

02Developing high-quality features in existing (brownfield) projects

03Aligning team requirements and architectural decisions before AI generation

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add ruan-cat/monorepo openspec

For use in Claude.ai and ChatGPT

Download Skill