Announcing Axon Framework 5: Configuring Axon made easy.

Today we are officially launching the first milestone of Axon Framework 5.0.0, and needless to say, everyone here at AxonIQ is excited about the new release! For those who are unaware, Axon Framework has long been the default go-to solution for implementing event-driven microservices with Java and JVM-based systems. Now, with the release of Axon Framework 5, we aim to broaden the Framework’s capabilities while reducing complexity for both veterans and newcomers alike. We think that the best way to accomplish this (and to give the community time to adapt to the new APIs and paradigms) is to deliver the full release in milestones — continuing to make event sourcing easy!

We’re making milestone releases as we follow our roadmap for 2025

Have you seen our product development Roadmap for 2025? Because we have a ton of important features and capabilities in store for the community. The development team agreed that the best way to deliver Axon Framework 5 is to make our deliveries in the form of subsequent milestones. Why is this important? A milestone-based release schedule helps everyone in the community to know the following three things:

1. We know where we want to go with Axon Framework 5

2. We know how we plan to get there

3. We don’t have intentions to “undo” previous ground covered in a milestone

At the end of the day, this means that each milestone release of Axon Framework 5 is ready for early adopters to explore, but should be purely for experimental purposes! Therefore, you can expect that a milestone will show a snapshot of the progress that bundles newly added functionality, improved APIs, and any compatible existing features so developers can begin working with them confidently.

The first milestone release of Axon Framework may (in some cases) feel like an alpha or beta release because we’re asking for feedback from the community as we develop and release new features. Therefore, one key reason why the development team opted for a milestone-based release schedule is to gather meaningful feedback early on from everyone in the community. Milestone releases indicate a relatively stable checkpoint while also making it clear that new capabilities are still forthcoming. This helps longtime users decide whether they can start planning a migration, even if not all Axon Framework 4 features are mirrored in the milestone just yet.

Another advantage is that milestones can be more frequent and more focused on tangible, distinct improvements. Whenever a notable piece of functionality is ready—such as the revamped Configuration API (more on that later) or refined test fixtures—it can be published in a milestone release for immediate evaluation. This incremental strategy is especially helpful for a community-driven project like Axon Framework, which is 100% open-source and where real-world feedback greatly influences future development goals, priorities, and timelines.

Therefore, what can you, as a member of the community, expect in the coming months? Today marks the first milestone of Axon Framework 5, and over the coming months, you can expect a series of additional milestones to be released until we announce the final 5.0.0 release. Each milestone release will carry forward the progress made in the previous iterations while filling in critical gaps that developers need to launch serious, production-grade systems. Although it may take time before Axon Framework 5.0.0 fully surpasses version 4 in terms of feature parity, every milestone brings the Framework closer to a final release that has been shaped directly by users, ensuring it meets the community’s evolving needs.

Configuring Axon made easy!

At the heart of Axon Framework 5’s revamp lies the new and improved Configuration API. For those of you who are already familiar with Axon Framework 4, you know that Axon Framework applications have historically relied heavily on Spring-based annotations. We acknowledge that Spring-based annotations are great and convenient (if you were already in the Spring ecosystem), but not every development team wants to use Spring.

So, in Axon Framework 5, the adjusted Configuration API addresses this complexity by segmenting the Framework into more intuitive “compartments.” Instead of sifting through dozens of configuration methods, developers can now focus on specific aspects like messaging, automations, or command models. If you’ve ever felt overwhelmed by the amount of boilerplate code needed to get a simple project running, then the features and capabilities available in the Configuration API of Axon Framework 5 are for you!

Additionally, if you’re not a fan of framework-specific annotations in your domain models, then you’ll love the builder-based approach that allows you to register event-sourced or state-based entities in a more explicit manner. Therefore, by stripping away Axon Framework-specific annotations, you have the option to maintain a pure domain model while still enjoying the Framework’s powerful tooling. This is a welcome change for those who want absolute clarity over what is happening under the hood, whether for philosophical reasons or for simpler interoperability with other libraries.

Let’s talk about migrating from 4 to 5

One of the biggest concerns for existing users will be how to migrate from Axon Framework 4 to 5. While the adjusted Configuration API offers a neater, more modular approach, it also requires some explanation if you’re accustomed to the previous configuration style. To facilitate this transition, the team has been working on examples and test suites that illustrate how to port existing applications to the new configuration paradigm.

If you’re perfectly fine with using annotations in your Axon Framework 4 application, then in many cases, your code will remain the same, especially if you stick to the annotation-based approach in Axon Framework 5. Where you might see changes is in how you tie everything together at the Configuration level—fewer steps are hidden behind “magic” and more deliberate registration of your command and event sourcing handlers, with more to come in the future. Think of it like a well-organized toolbox: each compartment is clearly labeled, so you know exactly what tool you’re picking up.

Are you looking for a concrete example showcasing the new approach? Then be sure to take a look at this article in AxonIQ Docs and the corresponding example repository. Alongside the documentation, we’re planning on releasing short demo videos to visually guide you through scenarios like building an event-sourced entity without annotations or constructing a microservices architecture where each component uses Axon’s messaging capabilities in a slightly different way.

So, who should use Axon Framework 5, and what should you expect in the Milestones?

The final release of Axon Framework 5.0.0 will cater to two groups. First, there are the experienced developers who are already using Axon Framework 4. For them, the revamped Configuration API, DCB support, and the new features that are on the Roadmap will be a welcomed change. The second group is for those who are entirely new to Axon Framework and are drawn by the framework’s approach to event sourcing. These developers might be wary of adopting a technology that feels too tied to Spring, or that requires framework-specific annotations in their domain models. Axon Framework 5 offers them a fresher start.

That said, these milestone releases (labeled “M1,” “M2,” etc.) will not (yet) contain all the features from Axon Framework 4. In other words, you shouldn’t expect complete “feature parity” out of the box with Axon Framework 4. This means that some organizations may wait until a final 5.0.0 release to ensure more polished and complete functionality.

Are you worried about missing features if you migrate too soon? In some cases, organizations relying on particular Axon Framework 4 features might choose to stay put until Axon Framework 5 gains complete feature parity. For others, especially greenfield projects or teams that don’t require every existing feature, it might be perfect timing to adopt version 5 and influence its future development through feedback.

Looking Ahead

Axon Framework 5 is officially here, and upcoming milestones will have more exciting features coming later in the year. We’re ensuring that videos, documentation updates, and blog posts will help you navigate this new territory, whether you’re a seasoned Axon Framework developer or if this is your first Event-Sourced application.

Looking for help on jumpstarting your Event-Sourced app with Java and Axon Framework? Feel free to use this form to book a chat with one of our solution architects to let us know what you’re working on. We’ll be happy to show you step-by-step on getting your project off the ground. Axon Framework is the #1 Event Sourcing Java Framework, and we’re happy to help your organization adapt to Event Sourcing, so feel free to contact us!