Why OpenSpec?

Agree before you build. Stay organized. Work fluidly. Use your tools.

🤝

Agree Before You Build

Human and AI align on specs before code gets written. No more vague prompts or unpredictable results.

📁

Stay Organized

Each change gets its own folder with proposal, specs, design, and tasks. Everything in one place.

🔄

Work Fluidly

Update any artifact anytime, no rigid phase gates. Iterate freely and adapt as you go.

🛠️

Use Your Tools

Works with 20+ AI assistants via slash commands. No lock-in, no vendor restrictions.

📊

Spec Delta Review

Understand changes at a high level without digging through code. Review proposals in seconds.

💾

Persistent Context

Specifications live alongside code in your repository. Context persists beyond chat sessions.

See It In Action

Simple workflow, powerful results

Create a Change

You: /opsx:new add-dark-mode

AI creates the change folder structure and prepares the proposal.

Generate Planning Docs

You: /opsx:ff # "fast-forward"

AI generates proposal.md, specs/, design.md, and tasks.md automatically.

Implement

You: /opsx:apply

AI implements all tasks systematically, following the specs and design.

Quick Start

Get started in minutes. Requires Node.js 20.19.0 or higher.

1. Install OpenSpec

npm install -g @fission-ai/openspec@latest

Also works with pnpm, yarn, bun, and nix

2. Initialize Your Project

cd your-project
openspec init

3. Start Building

# Tell your AI:
/opsx:new <what-you-want-to-build>

Supported Tools

OpenSpec works with 20+ AI coding assistants:

Claude Code Cursor GitHub Copilot Windsurf RooCode Cline Amazon Q Codex And 12+ more

View full list →

Example Workflow

Real-world usage example

You: /opsx:new add-dark-mode

AI: Created openspec/changes/add-dark-mode/
Ready to create: proposal

You: /opsx:ff # "fast-forward" - generate all planning docs

AI: ✓ proposal.md — why we're doing this, what's changing
✓ specs/ — requirements and scenarios
✓ design.md — technical approach
✓ tasks.md — implementation checklist
Ready for implementation!

You: /opsx:apply

AI: Implementing tasks...
✓ 1.1 Add theme context provider
✓ 1.2 Create toggle component
✓ 2.1 Add CSS variables
✓ 2.2 Wire up localStorage
All tasks complete!

You: /opsx:archive

AI: Archived to openspec/changes/archive/2025-01-23-add-dark-mode/
Specs updated. Ready for the next feature.

How We Compare

OpenSpec vs alternatives

vs. Spec Kit (GitHub)

Spec Kit: Thorough but heavyweight. Rigid phase gates, lots of Markdown, Python setup.

OpenSpec: Lighter and lets you iterate freely. No Python required. 5-minute setup vs 30 minutes.

vs. BMAD

BMAD: Powerful multi-agent system but complex setup and steep learning curve.

OpenSpec: Simple, focused on spec management. Get started in minutes, not days.

vs. Kiro (AWS)

Kiro: Powerful but locked into their IDE and limited to Claude models.

OpenSpec: Works with the tools you already use. No vendor lock-in.

vs. Nothing

Without specs: Vague prompts and unpredictable results. Context lost in chat history.

OpenSpec: Brings predictability without the ceremony. Persistent context.

View Detailed Comparison

OpenSpec: The Most Loved Spec Framework