Kafka (Write) block

The kafka_topic_write block pushes data to a Kafka topic. It acts as the destination block in a Connect+ dataflow, receiving processed data from upstream blocks and publishing it as messages to a specified Kafka topic. The block supports configurable Kafka client services, a message key for partitioning and identifying events within a topic, and header extraction as data attributes for routing and tracking downstream.

When to use this block

Use this block when your dataflow writes output messages to a Kafka topic as its final step. For example, forward processed records to a downstream Kafka-based system.

Prerequisites

Before configuring this block, ensure you have:

The name of the target Kafka topic
Access to the Event-notification-kafka or connectplus-kafka service
The Kafka key format for partitioning messages

Configuration fields

Field name	Required	Description
Block name	No	A name for the block instance. The name should be alphanumeric, and there is no limit on the number of characters.
Kafka client service to connect to server	Yes	The Kafka client service used to connect to the server. Use `Event-notification-kafka` when publishing event notification data. Use `connectplus-kafka service` when publishing to a custom topic created in Neo. Default value: `Event-notification-kafka`.
Kafka topic	Yes	The name of the Kafka topic to which messages are published. \|For example, `transactions_topic`.
Kafka key	Yes	A user-defined key that identifies each message within the topic and helps partition related events. For example, `${customerId}`.
Headers as Attribute	Yes	Specifies which Kafka message headers are extracted as data attributes and made available to downstream blocks. Select `Traceable Id` to extract only the traceable identifier, or `All` to extract all headers. Default value: `Traceable Id`.