Update April 2021: App Bridge 2.0 now available
Migrating to App Bridge 2.0 will ensure your app is aligned with the future of Shopify. This new release of App Bridge also includes a more streamlined interface for actions and an improved architecture for tree-shaking.Learn more
Embedded apps are a crucial part of the Shopify ecosystem, allowing merchants to add functionality to their shops without leaving the familiar environment of the Shopify Admin. As a Shopify app developer, you've no doubt recognized the opportunity of building embedded apps to provide merchants with additional capabilities to help grow their businesses.
Over time, embedded apps have evolved from a tiny experiment to become more powerful than we could ever have imagined. Initially, Shopify Partners used tools called the Embedded App Software Development Kit (EASDK) and the Point of Sale Software Development Kit (POSSDK) to build embedded apps. But as our app ecosystem has grown, these tools haven't been able to keep up with developer needs.
Shopify App Bridge allows you to embed your app anywhere that merchants interact with their admin. A single front end written with Shopify App Bridge can power POS, desktop, and mobile experiences. Apps built with Shopify App Bridge are more performant and flexible, have more features, and can leverage hardware in a way that no other Shopify apps can. In this article, we look at the opportunities that developers can leverage using Shopify App Bridge.
Performance and flexibility
In a world before Shopify App Bridge, apps that wanted to be usable on both Shopify POS and the admin would need to use two separate client-side libraries: one for ShopifyPOS and one to embed in the web admin. Shopify App Bridge reduces this requirement to a single library, allowing for a more unified merchant experience and highly streamlined development flow.
Not only does Shopify App Bridge improve consistency and development efficiency, but it can also load apps up to four times faster than apps built with the EASDK or POSSDK.
You might also like: Building Shopify Apps: App Developers Share Their Experiences.
Actions and action sets
Actions are a new way for apps using Shopify App Bridge to interact with Shopify. By using actions, you gain control over many of Shopify's UI elements. The top bar, loading indicator, modals, resource pickers, and buttons are all available to make your app feel like a native Shopify experience. Actions can be easily dispatched to make things happen in context, like show a toast message or activate a contextual save bar.
The real power of actions is revealed once they're combined into action sets, persisted sets of actions that you can dispatch or subscribe to at any time. When you create an action set, its configuration is persisted and shared between Shopify and your app. Both sides are aware of the state of each action set: whether a modal is open, what lives inside the title bar, etc.
All action sets use the same interface to keep the API simple and consistent:
Create: Used to initialize an action set, sometimes with options.
Set: Allows you to update the configuration of an action set when available. For example, updating the title in the title bar.
Subscribe: Notifies you of events in Shopify’s UI, like when a modal is closed.
Dispatch: Sends actions to Shopify, activating functionality.
Aside from a few exceptions, creating an action set simply stores the configuration inside the shared state, and doesn’t do much on its own. Action sets get actions ready for you to dispatch.
Action types are statically defined actions that are available to action sets. These are the individual messages sent between your app and Shopify, to perform tasks and notify you of events. Using the toast message as an example, its action set is
Toast, and actions available to the toast action set are
CLEAR. Similarly, actions for the
Loading action set are
STOP. These are just two of the action sets available in Shopify App Bridge. As Shopify App Bridge continues to grow, we will be able to add even more action types to enable new capabilities.
Once you’ve created an action set, you can dispatch the actions it contains. You can also subscribe to actions dispatched by Shopify. For example, when a merchant closes a modal from the Shopify Admin, Shopify will dispatch a
CLOSE action that your app can subscribe to. Your app can provide a callback to be executed when the action is dispatched.
By combining a simple, consistent API—
subscribe—with statically defined actions, Shopify App Bridge offers you granular control with minimal cognitive overhead. This is also what makes Shopify App Bridge extensible. The use of actions also shifts away from methods tied to specific visual design. Instead, it provides you with composable building blocks grouped by their functionality.
Action sets also persist state transparently, allowing you to inspect the current state of your app using tools like Redux DevTools, and even replay past actions to help you debug.