> ## Documentation Index
> Fetch the complete documentation index at: https://spreecommerce.org/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Adding to an existing Rails app

> This guide will show you how to add Spree to an existing Ruby on Rails application.

<Warning>
  This guide is aimed at advanced users who want to add Spree to an existing Rails application. If you are new to Spree, please follow the [Quickstart guide](/getting-started/quickstart).
</Warning>

## Overview

If you already have a Ruby on Rails application, you can add Spree to it by following these steps.

<Info>
  Spree works with **PostgreSQL**, **MySQL**, and **SQLite** — whatever database your Rails app already uses. No database migration is needed.
</Info>

## 1. Add Spree gems

Add these lines to your project `Gemfile`:

```ruby theme={"theme":"night-owl"}
spree_opts = { 'github': 'spree/spree', 'branch': 'main' }
gem 'spree', spree_opts # core, API, and CLI
gem 'spree_admin', spree_opts # Admin panel (optional)
gem 'spree_emails', spree_opts # transactional emails (optional)
```

And run the following command to install the gems:

```bash theme={"theme":"night-owl"}
bundle install
```

## 2. Run the install generators

Spree uses a modular installation approach. First install the core, then add optional components.

### Install core Spree

This installs core models, API, CLI, and authentication:

```bash theme={"theme":"night-owl"}
bin/rails g spree:install --user_class=Spree::User --authentication=devise
```

**Core installation options:**

| Option             | Description                                           |
| ------------------ | ----------------------------------------------------- |
| `user_class`       | The class for your users, eg. `Spree::User` or `User` |
| `admin_user_class` | The class for admin users (defaults to `user_class`)  |
| `authentication`   | Authentication gem: `devise` or `custom`              |
| `migrate`          | Whether to run migrations (default: true)             |
| `seed`             | Whether to run the seed file (default: true)          |
| `sample`           | Whether to add sample data (default: false)           |
| `admin_email`      | Email of the first admin user                         |
| `admin_password`   | Password of the first admin user                      |

### Install Admin Panel (optional)

```bash theme={"theme":"night-owl"}
bin/rails g spree:admin:install
bin/rails g spree:admin:devise  # if using Devise authentication
```

### Add sample data (optional)

To add sample data to your store, run:

```bash theme={"theme":"night-owl"}
bin/rake spree:load_sample_data
```

This will add some products, categories and multiple markets to your store.

## Accessing Admin Panel

Navigate to [http://localhost:3000/admin](http://localhost:3000/admin) and log in with the default credentials:

|              |                     |
| ------------ | ------------------- |
| **Email**    | `spree@example.com` |
| **Password** | `spree123`          |

Upon successful authentication, you should see the admin screen:

<Frame caption="Spree Admin Dashboard">
  <img src="https://mintcdn.com/spreecommerce/cQFxCIv2IPZLev6h/images/spree_admin_dashboard.png?fit=max&auto=format&n=cQFxCIv2IPZLev6h&q=85&s=effae741cd385f1dd8618eedd326449c" width="3024" height="1576" data-path="images/spree_admin_dashboard.png" />
</Frame>

***

Congrats! You've set up your Spree Commerce and it's looking amazing!

Give Spree a [GitHub Star](https://github.com/spree/spree)<Icon icon="star" iconType="solid" color="#FFD43B" />, why don't ya? Thank you for supporting Spree open-source! <Icon icon="heart" iconType="solid" color="#FF0000" />

Need support or want to give some feedback? Join our [Discord](https://discord.spreecommerce.org/)