We’re excited to announce the latest updates to ObjectBox Sync Server with our recent 2025-06-02 and 2025-05-27 releases. These updates bring significant improvements to data handling, authentication, and user interface, making your data synchronization experience even smoother.
Powering Up Your Data Flow
Exciting news for developers! Starting from late May 2025, ObjectBox Sync Server trials are publicly available as Docker images on Docker Hub. This means you can now effortlessly pull our Sync Server trial directly with a simple command:
| 1 | docker pull objectboxio/sync-server-trial |
This provides a straightforward, no-fuss way to start testing the Sync Server with your data. Each trial gives you 30 days per dataset to explore the full spectrum of ObjectBox Sync capabilities, allowing you to experience its power and ease of use firsthand.
New “JSON to Native” External Property Type
Managing complex, nested JSON structures and mapping them to native database objects can be cumbersome and lead to data integrity issues. One of the most powerful additions in the 2025-05-27 release is the new “JSON to native” property type mapping. This feature allows you to convert strings to nested documents in MongoDB, providing a more elegant way to handle complex data structures. Note: This feature requires client version 4.3 or newer to function correctly.
Here’s how you can implement it in your applications:
| 1 2 3 | // Java @ExternalType(ExternalPropertyType.JSON_TO_NATIVE) private String myNestedDocumentJson; |
| 1 2 3 | // Kotlin @ExternalType(ExternalPropertyType.JSON_TO_NATIVE) var name: String? = myNestedDocumentJson |
| 1 2 3 | // Dart @ExternalType(type: ExternalPropertyType.jsonToNative) String? myNestedDocumentJson; |
| 1 2 3 | // Swift // objectbox: externalType="jsonToNative" var myNestedDocumentJson: String? |
Key Advantages of “JSON to Native”
- You can use your preferred JSON API to access the data
- It supports nested documents and arrays
- The order of keys is preserved, unlike with flex properties
Increased Maximum Sync Message Size
We’ve increased the maximum Sync message size to 32 MB, allowing for larger data transfers between clients and the server. This improvement is particularly useful for applications that need to synchronize larger chunks of data or complex documents. Clients version 4.3.0 and above are required.
Enhanced JWT Authentication
JWT authentication has been improved with more flexible options for public key configurations. Public key URLs can now refer directly to PEM public key or X509 certificate files, in addition to the previously supported JSON formats.
This means you can now use the following formats for your public key URL:
- Key-value JSON file
- JWKS (JSON Web Key Set)
- PEM public keyfile
- PEM certificate file
This enhancement provides more flexibility when integrating ObjectBox Sync Server with various authentication providers and existing security infrastructures..
Admin UI Improvements
The 2025-06-02 release includes several user experience improvements to the Admin UI:
- Resolved issues on the GraphQL page for more reliable interactions
- Enhanced menu UI with improved icons and optimized padding for better visual clarity and navigation
Getting Started with the ObjectBox Sync Server Trial (including the MongoDB Connector)
If you haven’t tried ObjectBox Sync Server yet, now is a great time to start! With our publicly available Docker images, you can quickly set up and start testing (just ensure Docker is installed on your system):
| 1 2 3 4 5 6 7 8 9 | docker run --rm -it \ --volume "$(pwd):/data" \ --publish 127.0.0.1:9999:9999 \ --publish 127.0.0.1:9980:9980 \ --user $UID \ objectboxio/sync-server-trial \ --model /data/objectbox-model.json \ --unsecured-no-authentication \ --admin-bind 0.0.0.0:9980 |
- Note: this assumes you already have an existing data model (objectbox-model.json) ready. If you don’t, you can use the existing ObjectBox Sync Examples repository for a quick start.
- Then, access the Admin UI by opening your web browser and navigate to
http://127.0.0.1:9980 - Follow the on-screen instructions in the Admin UI to activate your 30-day trial per dataset.
Or just go here to register and follow the step by step guide to get syncing now.
If you are using Java, you can also follow this 7 easy steps to sstart syncing your data in minutes.
What’s Next?
We’re continuously working to improve ObjectBox Sync to make your data synchronization experience seamless and robust. Stay tuned for more updates and improvements in the coming months!
For detailed information about these features, please refer to our documentation: