https://docs.confluent.io/platform/current/connect/transforms/overview.html
Cast|Cast fields or the entire key or value to a specific type (for example, to force an integer field to a smaller width).
Drop|Drop either a key or a value from a record and set it to null.
DropHeaders|Not currently available for managed connectors. Drop one or more headers from each record.
EventRouter|Only available for managed Debezium connectors. Route Debezium outbox events using a regex configuration option.
ExtractField|Extract the specified field from a Struct when schema present, or a Map in the case of schemaless data. Any null values are passed through unmodified.
ExtractTopic|Replace the record topic with a new topic derived from its key or value.
Filter (Apache Kafka)|Drop all records. Designed to be used in conjunction with a Predicate.
Filter (Confluent)|Include or drop records that match a configurable filter.condition.
Flatten|Flatten a nested data structure. This generates names for each field by concatenating the field names at each level with a configurable delimiter character.
GzipDecompress|Not currently available for managed connectors. Gzip-decompress the entire byteArray key or value input.
HeaderFrom|Not currently available for managed connectors. Moves or copies fields in a record key or value into the record’s header.
HoistField|Wrap data using the specified field name in a Struct when schema present, or a Map in the case of schemaless data.
InsertField|Insert field using attributes from the record metadata or a configured static value.
InsertHeader|Not currently available for managed connectors. Insert a literal value as a record header.
MaskField|Mask specified fields with a valid null value for the field type.
MessageTimeStampRouter|Update the record’s topic field as a function of the original topic value and the record’s timestamp field.
RegexRouter|Not currently available for managed connectors. Update the record topic using the configured regular expression and replacement string.
ReplaceField|Filter or rename fields.
SetSchemaMetadata|Set the schema name, version, or both on the record’s key or value schema.
TimestampConverter|Convert timestamps between different formats such as Unix epoch, strings, and Connect Date and Timestamp types.
TimestampRouter|Update the record’s topic field as a function of the original topic value and the record timestamp.
TombstoneHandler|Manage tombstone records. A tombstone record is defined as a record with the entire value field being null, whether or not it has ValueSchema.
TopicRegexRouter|Only available for managed Source connectors. Update the record topic using the configured regular expression and replacement string.
ValueToKey|Replace the record key with a new key formed from a subset of fields in the record value.