# Add-ons
If you want to offer an app that requires another app to be installed, we offer add-ons.
Add-on are offered together with the main app in the Zaikio App Store and cannot be installed or subscribed to on their own.
Add-ons have exactly one main app and may only offer one plan (per offering). Otherwise, they are no different from other apps.
# Creating Add-ons
To create add-ons, the type Add-on must be selected during the app creation process and the main app must be selected as the parent of the add-on.
# Listing Add-ons in main app
Using the GET /organization/addons
endpoint (see Zaikio Hub API specification) you can list all published Add-ons for your app. You can also see if the authorized organisation is already connected or subscribed to this add-on.
# In-app purchase
In addition to listing each app, a redirect flow for creating subscriptions is also available, which brings customers back to a specific URL after they've completed the subscription process in the Zaikio hub.
Navigate to Add-ons in the sidebar of your app to manage permitted redirect URLs.
By redirecting the user to:
https://hub.sandbox.zaikio.com/addons/{ADDON_NAME}/subscriptions/new?organization_id={ORGANIZATION_ID}&redirect_uri=http://example.com/addon/subscription
Where ADDON_NAME
is the technical name of the Add-on app and ORGANIZATION_ID
is the UUID of the organisation that should subscribe to the Add-on. http://example.com/addon/subscription
should be the redirect URL that you added to list of allowed redirect URLs.
Once the organisation completes the subscription process in Zaikio, it is redirected back with the following parameters:
http://example.com/addon/subscription?organization_id={ORGANIZATION_ID}&addon={ADDON_NAME}
Where ADDON_NAME
is the technical name of the Add-on app and ORGANIZATION_ID
is the UUID of the organisation that subscribed to the Add-on.