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The JTL platform has three different event systems depending on what you’re building and what kind of events you need to handle. This guide explains each one, how they differ, and when to use which.

Event Systems at a Glance

AppBridge Events

In development: AppBridge publish/subscribe events are in development and not yet available. This section will be updated when the API ships.
What they will be: Real-time, bidirectional events between your Cloud App and the App Shell. Your app can both publish events (tell the host something happened) and subscribe to events (react when the host tells you something happened). How they will work: AppBridge events use the iframe messaging channel. When your app publishes an event, the App Shell receives it instantly. When the App Shell publishes an event, your app’s subscriber callback fires immediately. Communication is asynchronous and non-blocking, so your app continues executing while the message is delivered (no HTTP request, polling, or delay). When to use them (planned):
  • Notifying the JTL App Shell that your app completed an action (e.g. order verification finished)
  • Reacting to user navigation or context changes in the JTL-Wawi
  • Coordinating between your app and other platform components

Publish and Subscribe

AppBridge events will support two capabilities:
  • Publishing events: your app notifies the host that something happened (for example, a verification step completed or a generated description is ready to insert).
  • Subscribing to events: your app listens for events from the host and reacts when context changes (for example, the merchant navigates to a different record).
Topics will follow a resource:action naming convention (for example, order:verification:complete or inventory:updated) so the intent of an event is clear from its name alone.

Key Characteristics

Lifecycle Hooks

What they are: A URL defined in your app’s app.json that JTL loads in an iframe when a merchant installs your app. How they work: You define a configurationUrl in the lifecycle section of your manifest. When a merchant installs your app, JTL loads that URL inside the JTL Hub. Your app shows its onboarding UI, completes the AppBridge handshake, and signals setup is done by calling appBridge.method.call('setupCompleted'). When to use it:
  • Showing onboarding UI when a merchant installs your app
  • Verifying the session token from AppBridge and persisting the tenant connection
  • Collecting any configuration the merchant needs to provide

Manifest Configuration

The lifecycle hook is defined in your app.json:

Key Characteristics

The configurationUrl is the most important lifecycle hook. It’s the entry point for the merchant’s first interaction with your app. If this URL is unreachable when a merchant tries to install your app, the installation fails. Make sure it’s always available.
For implementation details, see the Quick Start: From Scratch guide, which walks through the full setup handshake.

SCX Events (Polling)

What they are: An event queue for marketplace channel integrations. When sellers (merchants using JTL) take actions like creating a new product offer, updating prices, or shipping an order, those actions are queued as events. Your channel integration polls the queue, processes the events, and acknowledges them. How they work: This is a pull-based system, not push-based. JTL doesn’t send events to your server. Instead, your app periodically calls GET /v1/channel/event to check for new events, processes them, and then calls DELETE /v1/channel/event to acknowledge them. Unacknowledged events are redelivered. When to use them:
  • Processing new product listings from sellers
  • Handling order status updates (paid, shipped, cancelled)
  • Syncing attribute and category changes

Poll → Process → Acknowledge

  1. Poll: Your app calls GET /v1/channel/event at regular intervals (recommended: every 60 seconds)
  2. Process: Handle each event based on its type (new offer, order update, attribute change, etc.)
  3. Acknowledge: Call DELETE /v1/channel/event with the IDs of events you’ve successfully processed

Event Structure

Each event in the eventList has this shape:

Acknowledging Events

After processing, acknowledge events by sending their IDs:
Always acknowledge events after successful processing. If you don’t acknowledge an event, it will be redelivered after a timeout — up to 10 times. After 10 delivery attempts, the event becomes a failed event and is permanently discarded.

Key Characteristics

Best Practices for SCX Event Polling

Choosing the Right Event System


What’s Next?

Cloud Apps: Handling Webhooks

Implementation guide for AppBridge events and lifecycle hooks in Cloud Apps.

Marketplace Channels: Channel API

Full guide to building a marketplace channel integration, including SCX event handling.

Rate Limiting

Manage your API usage when polling for events at regular intervals.

Error Handling

Handle failures in event processing and API calls.