Kafka Connect InsertField SMT Usage Reference for Confluent Cloud

The org.apache.kafka.connect.transforms.InsertField Apache Kafka® Single Message Transform (SMT) inserts fields into a record using metadata attributes or a configured static value.

Description

The InsertField SMT inserts fields using attributes from the record metadata or a configured static value.

Use the concrete transformation type designed for the record key (org.apache.kafka.connect.transforms.InsertField$Key) or value (org.apache.kafka.connect.transforms.InsertField$Value).

Examples

The following two configuration snippet examples show how to use the InsertField SMT.

Inserting a static field

To insert a static field, use transforms.InsertField.static.field and transforms.InsertField.static.value to include the defined static field and value. In this example, the field is MessageSource with the value Kafka Connect framework.

"transforms": "InsertField",
"transforms.InsertField.type": "org.apache.kafka.connect.transforms.InsertField$Value",
"transforms.InsertField.static.field": "MessageSource",
"transforms.InsertField.static.value": "Kafka Connect framework"

Before: {"author": "Philip K. Dick", "character": "Palmer Eldritch"}

After: {"author": "Philip K. Dick", "character": "Palmer Eldritch", "MessageSource": "Kafka Connect framework"}

Inserting a field into the record key

To insert a field into the record key instead of the value, use the InsertField$Key transformation type with any of the field-name properties listed in the Properties table, such as topic.field. InsertField has no separate key.field property.

"transforms": "InsertField",
"transforms.InsertField.type": "org.apache.kafka.connect.transforms.InsertField$Key",
"transforms.InsertField.topic.field": "SourceTopic"

Before: key {"id": 42}

After: key {"id": 42, "SourceTopic": "orders"}

For more examples, see Insert Field for managed connectors.

Properties

Name	Description	Type	Default	Valid Values	Importance
offset.field	Field name for Apache Kafka® offset. This is only applicable to sink connectors. Suffix with ! to make this a required field, or ? to keep it optional (the default).	String	Null		Medium
partition.field	Field name for Kafka partition. Suffix with ! to make this a required field, or ? to keep it optional (the default).	String	Null		Medium
static.field	Field name for static data field. Suffix with ! to make this a required field, or ? to keep it optional (the default).	String	Null		Medium
static.value	The static value for the field specified in static.field.	String	Null		Medium
timestamp.field	Field name for record timestamp. Suffix with ! to make this a required field, or ? to keep it optional (the default).	String	Null		Medium
topic.field	Field name for Kafka topic. Suffix with ! to make this a required field, or ? to keep it optional (the default).	String	Null		Medium

Predicates

Transformations can be configured with predicates so that the transformation is applied only to records which satisfy a condition. You can use predicates in a transformation chain and, when combined with the Kafka Connect Filter (Kafka) SMT Usage Reference for Confluent Cloud, predicates can conditionally filter out specific records. For details and examples, see Predicates.