How can I use the `postEvent` API to trigger a Customer Journey and send a personalized push notification?

You can instantly send a personalized push notification to a specific user based on an external trigger by combining the /postEvent API method with a Customer Journey. This is ideal for transactional notifications like order status updates.

Here’s how to set it up:

1. Create a Trigger-Based Customer Journey

First, you need a Journey that will listen for your API call and send the message.

1. Set the Entry Point: Create a new Customer Journey and choose Trigger-based as the entry point. Select Event as the trigger source. You can create a new event, for example, OrderReady.
2. Target by UserID: In the entry element settings, ensure you are targeting users by their UserID. This allows the Journey to start for the specific user identified in your API call.
3. Add a Push Message: Drag a Push Message element onto the canvas and connect it to the entry point.

4. Personalize the Content: In the push message editor, use Dynamic Content (Liquid templates) to insert data from the event attributes you'll be sending. Use the format {{ event_attribute.attribute_name | default: "fallback_value" }}.

   For example, if you plan to send name and item attributes, your message could be:

   Hi {{ event_attribute.name | default: "there" }}! Your {{ event_attribute.item | default: "order" }} is ready for pickup.

2. Trigger the Journey with a postEvent API Call

From your external system or backend, send a POST request to the /postEvent endpoint when you want to trigger the notification.

The request body must contain: * application: Your Pushwoosh Application Code. * userId: The User ID of the recipient. This must match the User ID registered in Pushwoosh. * event: The code for the event that triggers your Journey (e.g., OrderReady). * attributes: A JSON object containing the key-value pairs for personalization. The keys must match the attribute names used in your push message template.

Example API Request

Here is an example using cURL:

curl --request POST \
     --url https://api.pushwoosh.com/json/1.3/postEvent \
     --header 'Authorization: Token YOUR_API_ACCESS_TOKEN' \
     --header 'Content-Type: application/json' \
     --data '{
       "request": {
         "application": "XXXXX-XXXXX",
         "userId": "u12345",
         "event": "OrderReady",
         "attributes": {
           "name": "John",
           "item": "Latte"
         }
       }
     }'

When this API call is made, the Customer Journey will start for the user with userId "u12345", and they will receive a push notification that reads: "Hi John! Your Latte is ready for pickup."