# Step 1: Set up

> Get your AI tools and the product repo onto your computer. You do this once, when you first join a repo.

Setup is the most engineer-dependent part, so it's the best place to ask for help. Everyone starts by asking.

## AI tools

You have three ways to run your AI assistant:

- **Claude Code desktop app** (easiest): a standalone app, no code editor needed.
- **Claude Code in the terminal**: the command-line version.
- **A code editor** like VS Code or Cursor, with the [Claude Code extension](https://code.claude.com/docs/en/vs-code).

You sign in with a Claude account. The desktop app uses a personal subscription (Pro or Max). To use API credits your organisation provides, use the terminal or an editor. Any of them works; the steps are the same, only the interface differs. (A common setup: Claude Code on the desktop app for building, and Codex for a second opinion on review.)

Getting your computer ready (the app or editor, plus a few tools the project needs) is a one-time setup an engineer can walk you through. To do it yourself, Claude Code's [setup guide](https://code.claude.com/docs/en/setup) covers it. Some repos also ship a design harness you install once; on a dx-harness repo, see [Install](/harness/install).

## Product repo

Most of this happens once. The first time, ask an engineer to walk through it with you.

### 1. Get access

An engineer adds you to the repo (on GitHub or GitLab) so you're allowed in.

### 2. Clone it

Cloning downloads the code to your computer.

- On the repo's web page, select **Code** and copy the **HTTPS** address (it starts with `https://`).
- Run `git clone [address]`, or ask your AI to do it.
- You sign in once; your computer remembers it after that (Keychain on a Mac, credential helpers on Windows and Linux). SSH, the `git@…` address, is an alternative some teams prefer.

> **Keep your access safe.** Your login is personal, so never share it or use a teammate's. Never put a token or key into a commit, an AI prompt, Slack, or email.

### 3. Get the `.env` values

A `.env` file holds the app's settings and secret keys, like a database address or an API key, kept out of the repo on purpose.

- Your engineer sends the real values through a secure channel, like a password manager or vault, not plain Slack.
- Paste them into your local `.env`. Without them, the app won't start.

### 4. Start the preview

Ask your AI for the command to run the project; it can read the repo and tell you exactly.

- The app opens in your browser at an address like `http://localhost:5173`. That's your **preview**: your own copy, where you view and test your changes.
- Start it fresh each session. If it stops, that's normal; ask your AI to start it again.
- Some apps need other pieces too, like a database; an engineer helps set those up the first time.