airbyte/docs/platform/understanding-airbyte/airbyte-metadata-fields.md

Airbyte metadata fields

In addition to the fields declared in a stream's schema, Airbyte destinations append additional columns to your data. These fields can aid in understanding your data and debugging errors.

Available metadata fields

Airbyte field	Description	Column type
_airbyte_raw_id	A random UUID assigned to each incoming record	String
_airbyte_generation_id	Incremented each time you execute a refresh	String
_airbyte_extracted_at	A timestamp for when Airbyte pulled the event from the data source	Timestamp with timezone
_airbyte_loaded_at	Timestamp to indicate when Airbyte loaded the record into the destination	Timestamp with timezone
_airbyte_meta	Additional information about the record; see below	Object

Note that not all destinations populate the _airbyte_loaded_at field. It's typically only useful for destinations that execute typing and deduping.

The _airbyte_meta field

This field contains additional information about the record. Airbyte writes it as a JSON object. It has two fields.

• A sync_id field on this object. This ID has no inherent meaning, but increases monotonically across syncs.

• A changes field, which records any modifications that Airbyte performed on the record. For example, if a record contained a value which didn't match the stream's schema, the destination connector could write null to the destination and add an entry to the changes list.

Each entry in the changes list is itself an object. The Airbyte protocol defines the schema for these objects, as the AirbyteRecordMessageMetaChange struct.

For example, if you saw this value in _airbyte_meta:

{
  "sync_id": 1234,
  "changes": [
    {
      "field": "foo",
      "change": "NULLED",
      "reason": "DESTINATION_SERIALIZATION_ERROR"
    }
  ]
}

You would know:

• Airbyte wrote this record during sync 1234
• Airbyte nulled the foo column because it wasn't a valid value for the destination

Connectors that Predate Destinations V2

Destinations that predate Destinations V2 have a different set of metadata fields. Some fields aren't supported pre-DV2, and other fields are present under a different name.

Airbyte field	Destinations V2 equivalent
_airbyte_ab_id	_airbyte_raw_id
_airbyte_emitted_at	_airbyte_extracted_at
_airbyte_loaded_at	_airbyte_loaded_at