Framework-agnostic domain model and SPI for chainsync. Zero third-party runtime dependencies.

The synchronization engine: adaptive polling, reorg handling, resume and multi-RPC failover, built on web3j.

Spring Boot auto-configuration: add the dependency, set a few properties, done.

JDBC-backed CursorStore and a block-persisting BlockHandler. Works with any JDBC DataSource.

Kafka-backed BlockHandler: publishes each synced block as a JSON message.