We are excited to announce the launch of crossfiresync, released on April 16, 2024. This new project brings powerful real-time replication capabilities to Google Cloud Platform (GCP) Firestore, allowing developers to synchronize data across different GCP regions seamlessly.

What is crossfiresync?

crossfiresync is a Java-based library that enables the replication of Firestore document changes—including inserts, updates, and deletes—across multiple regions. By leveraging GCP Pub/Sub as the transport layer, it creates an event-driven pipeline that ensures your data remains consistent regardless of where it is accessed.

The system operates through two key components deployed as Cloud Functions:

  • FirestoreChangePublisher: Listens for document writes in a source region and publishes those changes to a Pub/Sub topic.
  • PubSubChangeConsumer: Subscribes to the Pub/Sub topic and applies those changes to the local Firestore instance in the target region.

Depending on your needs, you can choose between two replication strategies:

  • Single Region Primary: A straightforward setup where all writes occur in one primary region, which then replicates to others.
  • Multi Region Primary: A more advanced mode allowing writes in any region, providing maximum availability and resilience.

Why it matters

For applications with a global user base, latency and availability are critical. By replicating Firestore data across regions, crossfiresync helps you:

  • Reduce Latency: Serve data from the region closest to your users.
  • Increase Availability: Ensure your application remains operational even if a specific GCP region experiences an outage.
  • Simplify Disaster Recovery: Maintain a real-time copy of your critical data in a secondary region.

Getting Started

crossfiresync is designed for Java 17 and integrates directly with the Google Cloud ecosystem. To get started, you will need a GCP project with both Firestore and Pub/Sub enabled.

You can add crossfiresync to your project via Maven:

<dependency>
    <groupId>com.unitvectory</groupId>
    <artifactId>crossfiresync</artifactId>
    <version>0.0.1</version>
</dependency>

Whether you are building a globally distributed application or simply looking to harden your infrastructure against regional failures, crossfiresync provides the foundational tools to keep your Firestore data in sync.

Transparency Note: This post was AI-generated using the model unsloth/gemma-4-31B-it-GGUF:UD-Q5_K_XL. It was generated on April 10, 2026, based on the crossfiresync repository and the v0.0.1 release. Author: release-storyteller