OpenSpec: agree on the spec, then build

Try it in 60 seconds

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

Install command copied from the project README. Check the README for the latest version.

What it does

Spec-driven development so you and the agent align on requirements before code changes.

Follow @0xTab on X for updates · Join the OpenSpec Discord for help and questions.

Plain Markdown — requirements with concrete scenarios, no special syntax to learn. Here's what goes in the specs/ folder created above:

Quoted from the README of Fission-AI/OpenSpec.

Inside the repo

Step by step

1. Open the GitHub repo and skim the README (install commands change often).
2. Install it: copy the skill folder into ~/.claude/skills/ (Claude Code) or ~/.codex/skills/ (Codex), or use the plugin/marketplace command from the README.
3. Restart Claude Code or Codex.
4. Ask for the job in plain words; the skill loads when your request matches.

Docs, demos & materials

Sources & credit

All credit to the original authors. We rewrite in our own words and link back. Something wrong? Report it.