OpenSpec Documentation

Welcome. This is the home for everything OpenSpec.

OpenSpec helps you and your AI coding assistant agree on what to build before any code is written. You describe the change, the AI drafts a short spec and a task list, you both look at the same plan, and then the work happens. No more discovering halfway through that the AI built the wrong thing.

If you read nothing else, read these two pages:

1. Getting Started: install, initialize, and ship your first change.
2. How Commands Work: where you actually type /opsx:propose (hint: in your AI chat, not the terminal). This trips up almost everyone once.

That second one matters more than it looks. OpenSpec has two halves: a command line tool you run in your terminal, and slash commands you give to your AI assistant. Knowing which is which saves you the most common moment of confusion.

The best habit to build first: when you’re not sure what to build, start with /opsx:explore. It’s a no-stakes thinking partner that reads your code, weighs options, and sharpens a fuzzy idea into a concrete plan before any code gets written. The Explore First guide makes the case.

Pick your path

I’m brand new. Start with Getting Started, then skim the Core Concepts at a Glance. When something feels mysterious, the FAQ and Glossary are nearby.

I have a problem but not a plan. This is the common case, and it has a dedicated answer: Explore First. Use /opsx:explore to think it through with the AI before committing to anything.

I have a big existing codebase. You don’t document all of it. Using OpenSpec in an Existing Project shows how to start on real, brownfield code without boiling the ocean.

I just want to get it working. Install, run openspec init, then read How Commands Work so your first slash command lands in the right place. Or hand the setup to your assistant with the AI-assisted install prompt.

I learn by example. The Examples & Recipes page walks through real changes start to finish: a small feature, a bug fix, a refactor, an exploration.

The AI just drafted a plan — now what? Read it. Reviewing a Change shows the two-minute pass that catches a wrong turn while it’s still cheap, and Writing Good Specs covers what a plan worth approving is made of.

I work on a team. OpenSpec on a Team shows how a change maps onto a branch and a pull request, and how teammates review a plan before the code.

I’m coming from the old workflow. The Migration Guide explains what changed and why, and promises your existing work is safe.

I want to bend it to my team’s process. Customization covers project config, custom schemas, and shared context.

Something’s broken. Troubleshooting collects the failures people actually hit, with fixes.

The whole map

Start here

Doc	What it gives you
Getting Started	Install, initialize, and run your first change end to end
Explore First	Use /opsx:explore to think through an idea before you commit
How Commands Work	Where slash commands run, what “interactive mode” means, terminal vs chat
Core Concepts at a Glance	The whole mental model on one page: specs, changes, deltas, archive
Installation	npm, pnpm, yarn, bun, Nix, a prompt that hands setup to your AI assistant, and how to verify it worked

Use it day to day

Doc	What it gives you
Workflows	Common patterns and when to reach for each command
Examples & Recipes	Full walkthroughs of real changes, copy-pasteable
Writing Good Specs	What a strong requirement and scenario look like, and how to right-size a change
Reviewing a Change	The two-minute pass on a drafted plan before any code is written
OpenSpec on a Team	How changes fit branches, pull requests, and review
Using OpenSpec in an Existing Project	Adopting OpenSpec on a large brownfield codebase
Editing & Iterating on a Change	Update artifacts, go back, reconcile manual edits
Commands	Reference for every /opsx:* slash command
CLI	Reference for every openspec terminal command

Understand it deeply

Doc	What it gives you
Concepts	The long-form explanation of specs, changes, artifacts, schemas, and archive
OPSX Workflow	Why the workflow is fluid instead of phase-locked, plus an architecture deep dive
Glossary	Every term defined in one place

Make it yours

Doc	What it gives you
Customization	Project config, custom schemas, shared context
Multi-Language	Generate artifacts in languages other than English
Supported Tools	The 30+ AI tools OpenSpec integrates with, and where files land
Community Showcase	Projects and resources built with and for OpenSpec

When you need help

Doc	What it gives you
FAQ	Quick answers to the questions people ask most
Troubleshooting	Concrete fixes for concrete failures
Migration Guide	Moving from the legacy workflow to OPSX

Coordinate across repos (beta)

Doc	What it gives you
Stores: User Guide	Plan in its own repo when your work spans repos or teams
Agent Contract	The machine-readable CLI surfaces agents drive

The thirty-second version

1. Install        npm install -g @fission-ai/openspec@latest
2. Initialize     cd your-project && openspec init
3. Explore        (in your AI chat)  /opsx:explore           ← optional, but a great habit
4. Propose        (in your AI chat)  /opsx:propose add-dark-mode
5. Build          (in your AI chat)  /opsx:apply
6. Archive        (in your AI chat)  /opsx:archive

Steps 1 and 2 happen in your terminal. The rest happen in your AI assistant’s chat. That split is the one thing worth memorizing, and How Commands Work explains exactly why. Step 3 is optional, but starting with /opsx:explore when you’re unsure is the habit most worth forming.

Where else to get help

• Discord: discord.gg/YctCnvvshC for questions, ideas, and help.
• GitHub Issues: github.com/Fission-AI/OpenSpec/issues for bugs and feature requests.
• openspec feedback "your message" sends feedback straight from your terminal (it opens a GitHub issue).

Found something in these docs that’s wrong, stale, or confusing? That’s a bug. Open an issue or a PR. Documentation improvements are some of the most valuable contributions you can make.