Validate

Validate rejects a Kafka message key or value that doesn't conform to a schema or type, before it's produced to a topic or before it's fetched back out. It's built on two resources:

• Schema Registry defines where a schema lives: embedded in zilla.yaml, read from the local filesystem, or fetched from a remote schema registry.
• Schema Enforcement defines the type or schema a message key or value is checked against, from primitives like string and int32 to schema-backed formats like avro, json, and protobuf.

A kafka binding combines both: the model decides how to parse and validate the message, and for schema-backed models, the catalog supplies the schema to validate against.

north_kafka_cache_client:
  type: kafka
  kind: cache_client
  options:
    topics:
      - name: items-snapshots
        value:
          model: avro
          catalog:
            my_catalog:
              - strategy: topic

A cache_client validates a message as it's produced to a topic; a cache_server can independently validate a message as it's fetched back out, rejecting one that doesn't match even if it was produced without validation. See Schema Enforcement for both cases.

Next Steps

• Schema Registry covers each catalog type Kafka Gateway supports and when to use it.
• Schema Enforcement covers each model type Kafka Gateway supports, from primitives to schema-backed formats.
• Transform covers transforming a message's representation once it's validated.