Last modified: Aug 29, 2023


Description of the Events capabilities in Altinn 3.

This section of the documentation is a work in progress. There are sections with missing or only partial documentation.

Design goals

Altinn Events was developed to make it easier for service developers to deliver dynamic and seamless user experiences, based on data from multiple systems.

Altinn Events provides developers a simple route to adding event-driven architecture to their existing service-oriented applications. Secure and scalable, Altinn Events uses Publish/Subscribe concepts to loosely couple disparate systems without relying on polling or database replication.

Main benefits

Reasons to consider using Altinn Events

For event publishers

  1. Simple HTTP interface to publish events to, as they occur.
  2. Security, scalability, reliability and auditing built-in.
  3. Altinn authorization services available for managing access to events for subscribers.

For event subscribers

  1. No need to continuously poll for updates.
  2. Simple API for creating and managing event subscriptions, including support for attribute-based filtering.
  3. Reliable delivery with automatic retry logic means events will be buffered for you in case your webhook is unavailable for a period of time.
  4. Built-in authorization policy execution ensures that your app won’t receive irrelevant notifications.

Pub/Sub vs Event streaming

There are two main event driven architecture models: Pub/Sub and Event streaming

Altinn Events is based on the Pub/Sub model which has simpler delivery constraints than event streaming. In particular, Altinn Events does not guarantee in-order delivery, nor exactly once delivery.

Consequentially, developers should make every effort to process events idempotently and anticipate the possibility of out-of-order message delivery.


What is an event?

An event is a lightweight notification message containing information about a single operation or state change for a specified entity. Each event is published by a single originator, referred to as the event publisher or source, on behalf of a single person, organization or asset, known as the subject. The operation or state change is referred to as the event type.

Technically, events are JSON documents conforming to the Cloud Event v1.0.2 specification. This specification defines a standard set of property names, accepted value formats and a mechanism for encapsulating additional message payload, such as XML or binary encoded data.

Here is an example of a typical event:

    "time": "2022-05-12T00:02:07.541482Z"

Here is an example of an event publish through Altinn:

    "time": "2022-05-12T00:02:07.541482Z"

Note the new properties resource and resourceinstance.

In addition to adhering to the specification, cloud events published through Altinn Events must include a set of Altinn specific extension attributes used to enable authorization of events and support easier filtering of events for subscribers.

What is a subscription?

Altinn Events allows you to register a custom webhook for receiving events. You can define various filters, including by source, type and resource.

For security reasons, the webhook endpoint must support HTTPS.

Before enabling event forwarding for a new subscription, Altinn Events sends a custom event to the provided webhook URL to ensure that it exists.

For more information, please see this developer guide

A note about standards

Why Cloud Events?

Basing our API on the Cloud Event standard ensures consistent support across programming languages, operating systems and network stacks. This same standard has been adopted by many cloud providers and a growing number of independent solution providers.

The official specification defines a scaleable approach to versioning and extensions, opening possibilities for future capabilities in a backwards compatible fashion.

Who can use Altinn Events?

Publishing of events is limited to Altinn apps at the moment. We are working on extending this service to additional parties such as application owners and other parties during the spring of 2023. Maskinporten authentication will be required in order to publish events on our platform.

Subscribing to events is openly available to end users, end user systems and application owners. Once additional parties gain access to publishing, the right to subscribe to events published through Altinn will be generally available to the public.*

Subscriptions will need to be authorized by the publisher, and Altinn’s terms and conditions will have to be signed before gaining access.