EventSourcingDB 1.2.0 Is Available

EventSourcingDB 1.2.0 is available for download. Since we shipped 1.1.0, we've spent a lot of time listening – at conferences like KanDDDinsky, in customer calls, through GitHub issues, and in direct conversations with teams running EventSourcingDB in production. This release is our response to what you told us you needed most.

If you're getting started, head to Installing EventSourcingDB for the latest binaries, Docker image instructions, and upgrade guidance. For teams already running EventSourcingDB, this post walks through what changed and why.

One pain point came up repeatedly when we talked to teams in audit-heavy environments: validating event signatures meant exporting data and running external scripts. That felt wrong. Events already carry signature and hash fields, but those were invisible to EventQL – you couldn't filter by them, project them, or validate them directly in queries.

With 1.2.0, EventQL now understands these fields throughout the editor: auto-completion suggests them, syntax highlighting recognises them, and query execution returns them alongside the rest of your event data. You can now validate signatures and hashes directly against EventSourcingDB without leaving the system or writing custom tooling.

For teams that need end-to-end auditability, this makes the entire pipeline verifiable from a single point. See the EventQL reference and Running EventQL queries guides for more details on working with EventQL.

A New Precondition for Safer Writes¶

We added a new precondition: isSubjectPopulated. It only allows writes when a subject already contains at least one event. That sounds simple, but it solves a class of bugs we kept seeing in the wild – accidental re-initialisation of aggregates, onboarding flows that wrote to the wrong subject, recovery scripts that created empty streams.

Instead of scattering guard clauses across services, you can now express that requirement declaratively where the events live. Teams who previewed the feature reported fewer "empty stream" defects and faster debugging when something did go wrong.

The Preconditions guide now covers isSubjectPopulated with scenarios showing how it pairs with EventQL-based checks. It's a small addition, but it closes a gap we've learned matters in production.

Operational Improvements¶

A few smaller changes that make day-to-day operations smoother:

• The management UI now shows a documentation link, so guidance is always one click away.
• If you start the server with the UI exposed on a browser-blocked port, EventSourcingDB emits a clear warning in the logs. We've seen this misconfiguration catch people off guard, so we made it visible early. See The Port 6000 Mystery for the full story behind this.
• We added German language support and a language switcher in the UI. It's a small detail, but multilingual teams told us it matters.

The Using the management UI guide covers these updates in more detail.

Documentation That Grows With the Product¶

Releases are as much about learning materials as they are about binaries. We published in-depth instructions for configuring EventAI, covering setup, security, privacy, prompt design, and troubleshooting. EventAI is powerful, but adopting AI responsibly means understanding how it works and where it fits. That guide gives you what you need to make informed decisions.

We also launched the External Resources page, which curates talks, podcasts, and articles from the wider Event Sourcing community. It's not just about EventSourcingDB – it's about the patterns and ideas that make event-driven systems work. Use it for workshops, onboarding, or your own learning.

And you're reading this on the EventSourcingDB blog, which is now the home for announcements, stories from the field, and behind-the-scenes insights. Pair it with the Getting Started walkthrough to build a complete learning path for new team members.

Growth and Feedback¶

It's been encouraging to see usage grow across the ecosystem. The .NET client SDK passed 5,000 downloads, the JavaScript/TypeScript SDK is nearing 3,000, and Rust is closing in on 4,000. Last week, Docker pulls crossed 10,000 on Docker Hub. These numbers matter to us not as vanity metrics, but because they show the growing interest in EventSourcingDB.

Meeting many of you at KanDDDinsky 2025 reinforced that. Conversations about CQRS, Event Sourcing, and keeping tooling simple directly shaped this release – from EventQL ergonomics to the management UI details. If you want to continue those discussions, the next chance to meet us in person is the Software Architecture Gathering in Berlin on November 25th and 26th, hosted by the iSAQB. We'd love to hear what you're building.

What's Next¶

Thank you to everyone who shared feedback, filed issues, and took the time to talk to us throughout 2025. 1.2.0 reflects what you asked for: stronger guarantees, clearer guard rails, and better guidance.

Download EventSourcingDB 1.2.0 today through Installing EventSourcingDB, upgrade your environments, and let us know what it unlocks for you. For the full list of changes, the changelog has every detail.

If you prefer a fully managed option, EventSourcingDB Cloud is currently in private beta. To join, email us at [email protected]. We're onboarding participants in waves to keep the experience smooth, and your feedback will help shape the service before general availability.