The most loved spec framework. Our philosophy: Follow @0xTab on X for updates · Join the OpenSpec Discord for help and questions. Using OpenSpec in a team? Email here for access to our Slack channel. OpenSpec Dashboard Requires Node.js 20.19.0 or higher. Install OpenSpec globally: Then navigate to your project directory and initialize: Now tell your AI: /opsx:propose If you want the expanded workf
Add this skill
npx mdskills install Fission-AI/openspecWell-documented spec framework with clear workflows and slash commands for AI-guided development
The most loved spec framework.
Our philosophy:
→ fluid not rigid
→ iterative not waterfall
→ easy not complex
→ built for brownfield not just greenfield
→ scalable from personal projects to enterprises
Tip:
New workflow now available! We've rebuilt OpenSpec with a new artifact-guided workflow.
Run
/opsx:propose "your idea"to get started. → Learn more here
Follow @0xTab on X for updates · Join the OpenSpec Discord for help and questions.
Using OpenSpec in a team? Email here for access to our Slack channel.
You: /opsx:propose add-dark-mode
AI: Created openspec/changes/add-dark-mode/
✓ 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.
OpenSpec Dashboard
Requires Node.js 20.19.0 or higher.
Install OpenSpec globally:
npm install -g @fission-ai/openspec@latest
Then navigate to your project directory and initialize:
cd your-project
openspec init
Now tell your AI: /opsx:propose
If you want the expanded workflow (/opsx:new, /opsx:continue, /opsx:ff, /opsx:verify, /opsx:sync, /opsx:bulk-archive, /opsx:onboard), select it with openspec config profile and apply with openspec update.
Note:
Not sure if your tool is supported? View the full list – we support 20+ tools and growing.
Also works with pnpm, yarn, bun, and nix. See installation options.
→ Getting Started: first steps
→ Workflows: combos and patterns
→ Commands: slash commands & skills
→ CLI: terminal reference
→ Supported Tools: tool integrations & install paths
→ Concepts: how it all fits
→ Multi-Language: multi-language support
→ Customization: make it yours
AI coding assistants are powerful but unpredictable when requirements live only in chat history. OpenSpec adds a lightweight spec layer so you agree on what to build before any code is written.
vs. Spec Kit (GitHub) — Thorough but heavyweight. Rigid phase gates, lots of Markdown, Python setup. OpenSpec is lighter and lets you iterate freely.
vs. Kiro (AWS) — Powerful but you're locked into their IDE and limited to Claude models. OpenSpec works with the tools you already use.
vs. nothing — AI coding without specs means vague prompts and unpredictable results. OpenSpec brings predictability without the ceremony.
Upgrade the package
npm install -g @fission-ai/openspec@latest
Refresh agent instructions
Run this inside each project to regenerate AI guidance and ensure the latest slash commands are active:
openspec update
Model selection: OpenSpec works best with high-reasoning models. We recommend Opus 4.5 and GPT 5.2 for both planning and implementation.
Context hygiene: OpenSpec benefits from a clean context window. Clear your context before starting implementation and maintain good context hygiene throughout your session.
Small fixes — Bug fixes, typo corrections, and minor improvements can be submitted directly as PRs.
Larger changes — For new features, significant refactors, or architectural changes, please submit an OpenSpec change proposal first so we can align on intent and goals before implementation begins.
When writing proposals, keep the OpenSpec philosophy in mind: we serve a wide variety of users across different coding agents, models, and use cases. Changes should work well for everyone.
AI-generated code is welcome — as long as it's been tested and verified. PRs containing AI-generated code should mention the coding agent and model used (e.g., "Generated with Claude Code using claude-opus-4-5-20251101").
pnpm installpnpm run buildpnpm testpnpm run dev or pnpm run dev:clitype(scope): subjectTelemetry
OpenSpec collects anonymous usage stats.
We collect only command names and version to understand usage patterns. No arguments, paths, content, or PII. Automatically disabled in CI.
Opt-out: export OPENSPEC_TELEMETRY=0 or export DO_NOT_TRACK=1
Maintainers & Advisors
See MAINTAINERS.md for the list of core maintainers and advisors who help guide the project.
MIT
Install via CLI
npx mdskills install Fission-AI/openspecOpenSpec is a free, open-source AI agent skill. The most loved spec framework. Our philosophy: Follow @0xTab on X for updates · Join the OpenSpec Discord for help and questions. Using OpenSpec in a team? Email here for access to our Slack channel. OpenSpec Dashboard Requires Node.js 20.19.0 or higher. Install OpenSpec globally: Then navigate to your project directory and initialize: Now tell your AI: /opsx:propose If you want the expanded workf
Install OpenSpec with a single command:
npx mdskills install Fission-AI/openspecThis downloads the skill files into your project and your AI agent picks them up automatically.
OpenSpec works with Claude Code, Claude Desktop, Cursor, Vscode Copilot, Windsurf, Continue Dev, Codex, Gemini Cli, Amp, Roo Code, Goose, Opencode, Trae, Qodo, Command Code. Skills use the open SKILL.md format which is compatible with any AI coding agent that reads markdown instructions.