Shopify's API implements JSON to manipulate each API resource in isolation, providing a RESTfulinterface. All API usage happens through Shopify apps created by either store owners for their own shops, or by Shopify Partners for use by store owners.
Any Shopify app that you create will use the Shopify API to access another shop's data and automate almost any action from their shop admin dashboard. When a shop installs your app, all they're really doing is giving your app permission to access their shop's data through the API.
To properly install your app, you will need to provide your app with an authentication mechanism. Authentication mechanisms allow your app to interact with other Shopify stores. Shopify uses OAuth 2.0as its primary authentication mechanism but many of our developers and Shopify advocates also have authentication mechanisms (typically referred to as gems, connectors or adapters) available through software development kits (SDK). These SDKs are available in several programming languages. Take a look at our Libraries to see what is available in your preferred programming language. You will need to authenticate your app to install it in your development store.
Note
When developing your app, please respect the API calls limit. The API call limit operates using a "leaky bucket" algorithm as a controller. You can read more about how this will affect your app here.cv
Should you run into any problems along the way please bring your questions to our developer forums.