Install & Init

One install, one command. By the end of this lesson you have a project directory with OpenSpec initialized and nothing else — a clean slate for lesson 03.

Install OpenSpec

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

Create your project and initialize

$ mkdir toast-notifications
$ cd toast-notifications
$ openspec init

OpenSpec will prompt you to select your AI tool. Pick the one you use — Claude Code, Cursor, Gemini CLI, or whatever's in the list. It sets up everything it needs for that tool automatically.

Your project looks like this afterward:

toast-notifications/
├── .claude/
└── openspec/
    ├── changes/
    ├── specs/
    └── config.yaml

The .claude folder is invisible — it's there, you don't need to touch it. The openspec/ folder is where your work lives. changes/ is where proposals and specs go. specs/ is where finalized specs accumulate over time. config.yaml is OpenSpec's configuration.

Nothing else yet. In lesson 03 you'll open your first change and write a proposal for the toast system — before a single line of code gets written.