Shopify API

The Shopify API gem allows Ruby developers to programmatically access the admin section of Shopify stores.

The API is implemented as JSON over HTTP using all four verbs (GET/POST/PUT/DELETE). Each resource, like Order, Product, or Collection, has its own URL and is manipulated in isolation. In other words, we’ve tried to make the API follow the REST principles as much as possible.

Usage

Requirements

All API usage happens through Shopify applications, created by either shop owners for their own shops, or by Shopify Partners for use by other shop owners:

Shop owners can create applications for themselves through their own admin: https://docs.shopify.com/api/authentication/creating-a-private-app
Shopify Partners create applications through their admin: http://app.shopify.com/services/partners

For more information and detailed documentation about the API visit https://developers.shopify.com/

Ruby version

This gem requires Ruby 2.3.1 as of version 4.3. If you need to use an older Ruby version then update your Gemfile to lock onto an older release than 4.3.

Installation

Add shopify_api to your Gemfile:

gem 'shopify_api'

Or install via gem

gem install shopify_api

Getting Started

ShopifyAPI uses ActiveResource to communicate with the REST web service. ActiveResource has to be configured with a fully authorized URL of a particular store first. To obtain that URL you can follow these steps:

First create a new application in either the partners admin or your store admin. For a private App you'll need the API_KEY and the PASSWORD otherwise you'll need the API_KEY and SHARED_SECRET.

If you're not sure how to create a new application in the partner/store admin and/or if you're not sure how to generate the required credentials, you can read the related shopify docs on the same.
For a private App you just need to set the base site url as follows:
```
shop_url = "https://#{API_KEY}:#{PASSWORD}@#{SHOP_NAME}.myshopify.com/admin"
ShopifyAPI::Base.site = shop_url
```
That's it, you're done, skip to step 6 and start using the API!

For a partner app you will need to supply two parameters to the Session class before you instantiate it:
```
ShopifyAPI::Session.setup(api_key: API_KEY, secret: SHARED_SECRET)
```
Shopify maintains omniauth-shopify-oauth2 which securely wraps the OAuth flow and interactions with Shopify (steps 3 and 4 above). Using this gem is the recommended way to use OAuth authentication in your application.
In order to access a shop's data, apps need an access token from that specific shop. This is a two-stage process. Before interacting with a shop for the first time an app should redirect the user to the following URL:
```
GET https://SHOP_NAME.myshopify.com/admin/oauth/authorize
```
with the following parameters:
- client_id – Required – The API key for your app
- scope – Required – The list of required scopes (explained here: https://help.shopify.com/api/guides/authentication/oauth#scopes)
- redirect_uri – Required – The URL where you want to redirect the users after they authorize the client. The complete URL specified here must be identical to one of the Application Redirect URLs set in the App's section of the Partners dashboard. Note: in older applications, this parameter was optional, and redirected to the Application Callback URL when no other value was specified.
- state – Optional – A randomly selected value provided by your application, which is unique for each authorization request. During the OAuth callback phase, your application must check that this value matches the one you provided during authorization. This mechanism is important for the security of your application.
- grant_options[] - Optional - Set this parameter to per-user to receive an access token that respects the user's permission level when making API requests (called online access). This is strongly recommended for embedded apps.
We've added the create_permission_url method to make this easier, first instantiate your session object:
```
session = ShopifyAPI::Session.new("SHOP_NAME.myshopify.com")
```
Then call:
```
scope = ["write_products"]
permission_url = session.create_permission_url(scope)
```
or if you want a custom redirect_uri:
```
permission_url = session.create_permission_url(scope, "https://my_redirect_uri.com")
```
Once authorized, the shop redirects the owner to the return URL of your application with a parameter named 'code'. This is a temporary token that the app can exchange for a permanent access token.

Before you proceed, make sure your application performs the following security checks. If any of the checks fails, your application must reject the request with an error, and must not proceed further.
- Ensure the provided state is the same one that your application provided to Shopify during Step 3.
- Ensure the provided hmac is valid. The hmac is signed by Shopify as explained below, in the Verification section.
- Ensure the provided hostname parameter is a valid hostname, ends with myshopify.com, and does not contain characters other than letters (a-z), numbers (0-9), dots, and hyphens.
If all security checks pass, the authorization code can be exchanged once for a permanent access token. The exchange is made with a request to the shop.
```
POST https://SHOP_NAME.myshopify.com/admin/oauth/access_token
```
with the following parameters:
- client_id – Required – The API key for your app
- client_secret – Required – The shared secret for your app
- code – Required – The token you received in step 3
and you'll get your permanent access token back in the response.

There is a method to make the request and get the token for you. Pass all the params received from the previous call and the method will verify the params, extract the temp code and then request your token:
```
token = session.request_token(params)
```
This method will save the token to the session object and return it. All fields returned by Shopify, other than the access token itself, are stored in the session's extra attribute. For a list of all fields returned by Shopify, read our OAuth documentation. If you requested an access token that is associated with a specific user, you can retreive information about this user from the extra hash:
```
# a list of all granted scopes
granted_scopes = session.extra['scope']
# a hash containing the user information
user = session.extra['associated_user']
# the access scopes available to this user, which may be a subset of the access scopes granted to this app.
active_scopes = session.extra['associated_user_scope']
# the time at which this token expires; this is automatically converted from 'expires_in' returned by Shopify
expires_at = session.extra['expires_at']
```
For the security of your application, after retrieving an access token you must validate the following:
1. The list of scopes in session.extra['scope'] is the same as you requested.
2. If you requested an online-mode access token, session.extra['associated_user'] must be present. Failing either of these tests means the end-user may have tampered with the url parameters during the OAuth authentication phase. You should avoid using this access token and revoke it immediately. If you use the omniauth-shopify-oauth2 gem these checks are done automatically for you.
For future sessions simply pass in the token and extra hash (optional) when creating the session object:
```
session = ShopifyAPI::Session.new("SHOP_NAME.myshopify.com", token, extra)
```

The session must be activated before use:

ShopifyAPI::Base.activate_session(session)

Now you're ready to make authorized API requests to your shop! Data is returned as ActiveResource instances:

shop = ShopifyAPI::Shop.current

# Get a specific product
product = ShopifyAPI::Product.find(179761209)

# Create a new product
new_product = ShopifyAPI::Product.new
new_product.title = "Burton Custom Freestlye 151"
new_product.product_type = "Snowboard"
new_product.vendor = "Burton"
new_product.save

# Update a product
product.handle = "burton-snowboard"
product.save

Alternatively, you can use #temp to initialize a Session and execute a command which also handles temporarily setting ActiveResource::Base.site:

products = ShopifyAPI::Session.temp("SHOP_NAME.myshopify.com", token) { ShopifyAPI::Product.find(:all) }

If you want to work with another shop, you'll first need to clear the session:
```
ShopifyAPI::Base.clear_session
```

Console

This package also supports the shopify-cli executable to make it easy to open up an interactive console to use the API with a shop.

Install the shopify_cli gem.

gem install shopify_cli

Obtain a private API key and password to use with your shop (step 2 in "Getting Started")
Use the shopify-cli script to save the credentials for the shop to quickly log in.
```
shopify-cli add yourshopname
```
Follow the prompts for the shop domain, API key and password.
Start the console for the connection.
```
shopify-cli console
```
To see the full list of commands, type:
```
shopify-cli help
```

Threadsafety

ActiveResource is threadsafe as of version 4.1 (which works with Rails 4.x and above).

If you were previously using Shopify's activeresource fork then you should remove it and use ActiveResource 4.1.

Using Development Version

Download the source code and run:

rake install

Additional Resources

API Reference: https://help.shopify.com/api/reference

Ask questions on the forums: http://ecommerce.shopify.com/c/shopify-apis-and-technology

tfitts/shopify_api