Using watch topics in Amplify Engage to trigger event notifications

Overview

Amplify Engage has long supported webhook-based event notifications, enabling platform administrators to respond to events such as:

• New APIs being discovered
• API lifecycle state changes
• API Product subscription requests

These events are typically sent to external systems like ServiceNow, Jira, or messaging platforms, where they can be logged and acted upon. However, webhook listeners must be configured on the target platforms, which may not always be feasible or practical.

To address this, Amplify Engage introduces watch topics — a powerful alternative notification pattern that simplifies event handling and enhances integration flexibility.

What are watch topics?

Watch topics allow Engage to place events onto a topic that can be queried by:

• Target applications
• Orchestration layers like Amplify Fusion

This enables asynchronous event processing without requiring direct webhook delivery. Watch topics are managed entirely within Engage, requiring only a topic definition and associated event filters.

Use case 1: notify when a new API product subscription is created

This is especially useful when the subscription approval process is set to Manual. API product owners can be alerted via email or external systems like ServiceNow.

Watch topic configuration (all environments)

{ 
  "group": "management", 
  "apiVersion": "v1alpha1", 
  "kind": "WatchTopic", 
  "name": "subscription-manual-approval",
  "title": "Subscription Approvals", 
  "attributes": {}, 
  "tags": [], 
  "spec": { 
    "filters": [ 
      { 
        "kind": "Subscription", 
        "name": "*", 
        "type": ["created"], 
        "group": "catalog" 
      } 
    ], 
    "description": "Watch for all create Subscription Requests" 
  } 
}

Limit to a specific environment

{ 
  "group": "management", 
  "apiVersion": "v1alpha1", 
  "kind": "WatchTopic", 
  "name": "subscription-manual-approval", 
  "title": "Subscription Approvals", 
  "attributes": {}, 
  "tags": [], 
  "spec": { 
    "filters": [ 
      { 
        "kind": "Subscription", 
        "name": "*", 
        "type": ["created"], 
        "group": "catalog", 
        "scope": { 
          "kind": "Environment", 
          "name": "my-env" 
        } 
      } 
    ], 
    "description": "Watch for all create Subscription Requests" 
  } 
}

Use case 2: notify when a new API version is created

When a new API version is discovered, a new APIServiceRevision is created. This watch topic tracks that event.

Watch topic configuration

{ 
  "group": "management", 
  "apiVersion": "v1alpha1", 
  "kind": "WatchTopic", 
  "name": "my-env-new-api-version", 
  "title": "Watch for new API versions in the my-env Environment", 
  "attributes": {}, 
  "tags": [], 
  "spec": { 
    "filters": [ 
      { 
        "kind": "APIServiceRevision", 
        "name": "*", 
        "type": ["created"], 
        "group": "management", 
        "scope": { 
          "kind": "Environment", 
          "name": "my-env" 
        } 
      } 
    ], 
    "description": "Watch for new API versions in the my-env Environment" 
  } 
}

Deploying the watch topic with the CLI

axway auth login 
axway central apply -f {filename.yaml}

View the attached Postman collection for examples on how to authenticate API calls, create, view and manage watch topics.

Querying the watch topic via API

https://apicentral.axway.com/events/management/v1alpha1/watchtopics/{{topicName}}?sort={{sortType}}

Where the optional sort parameter provides the ability to sort on the API response. A typical sortType is sequenceID, which will sort the results in sequential order.

https://apicentral.axway.com/events/management/v1alpha1/watchtopics/{{topicName}}?sort=sequenceID&query=sequenceID>120729043

Using the optional query parameter will filter the results based on the query. This example will only return results where the sequenceID is greater than the provided value. Use this to retrieve only results which occurred after the given sequenceID.

References

• Set up integrations through watch topics
• Amplify Engage API Documentation
• Install the Axway Central CLI Create a Service Account

Why this matters

Watch topics offer a flexible, scalable, and decoupled way to monitor and respond to platform events. They reduce dependency on external webhook configurations and enable seamless integration with orchestration tools like Amplify Fusion.

Ready to streamline your event-driven workflows?

Start using watch topics today to enhance your API governance, automate approvals, and improve operational efficiency across your digital ecosystem.