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Overview

The Confluent Avro SerDes connector for Ballerina provides Avro serialization and deserialization using the Confluent Schema Registry wire format. It integrates with the ballerinax/confluent.cregistry client to automatically register schemas during serialization and retrieve them by ID during deserialization, enabling seamless Avro-encoded data exchange over Apache Kafka and other messaging systems.

Key features​

  • Serialize any Ballerina value (records, primitives, arrays) to Avro-encoded bytes using a provided Avro schema
  • Automatically register Avro schemas in the Confluent Schema Registry under a specified subject during serialization
  • Deserialize Avro-encoded byte payloads back to typed Ballerina values using schema ID lookup from the registry
  • Implements the Confluent wire format: magic byte prefix + 4-byte schema ID + Avro payload
  • Type-safe deserialization via Ballerina's typedesc inference; no manual casting required
  • GraalVM native image compatible for high-performance, low-latency deployments
  • Works seamlessly with ballerinax/kafka for end-to-end Avro-encoded Kafka message pipelines

Actions​

Actions are module-level functions you call to serialize data to Avro bytes or deserialize Avro bytes back to typed Ballerina values. Both functions require an initialized cregistry:Client from ballerinax/confluent.cregistry to interact with the Confluent Schema Registry.

ClientActions
Avro SerDes FunctionsAvro serialization with schema registration, Avro deserialization with schema retrieval

See the Action Reference for the full list of operations, parameters, and sample code for each client.

Documentation​

  • Setup Guide: This guide walks you through enabling the Confluent Schema Registry on Confluent Cloud and obtaining the credentials required to use the Confluent Avro SerDes connector.

  • Action Reference: Full reference for all clients: operations, parameters, return types, and sample code.

How to contribute​

As an open source project, WSO2 welcomes contributions from the community.

To contribute to the code for this connector, please create a pull request in the following repository.

Check the issue tracker for open issues that interest you. We look forward to receiving your contributions.