Reference

Metadata

What every output records about how it was made.

SQLite outputs record metadata in a bagkit_metadata table of keys and values. CSV and Parquet tables put the same keys in metadata.json beside the table files.

{
  "schema_version": "1",
  "layout": "tables",
  "reference_date": "2026-10-08",
  "version": "0.1.0",
  "municipality_names": "PDOK brk-bestuurlijke-gebieden gemeentegebied, retrieved 2026-10-10",
  "object_types": "woonplaatsen,gemeenten,openbare-ruimten,nummeraanduidingen,adresseerbare-objecten,panden",
  "geometry": "included",
  "extract_date": "2026-10-08"
}

Key	Description
`schema_version`	The layout version. `query` and `serve` refuse databases of another version
`layout`	`tables` or `address_list` (an adreslijst)
`reference_date`	The peildatum voorkomens were selected for
`version`	The bagkit version that wrote the output
`municipality_names`	Where bagkit’s municipality table came from, and when
`object_types`	The object types that were read
`geometry`	`included` or `omitted`: whether geometrie was read
`extract_date`	The extract’s `StandTechnischeDatum`, when the inputs declare one date

In SQLite:

SELECT key, value FROM bagkit_metadata;

A single-file CSV or Parquet address list carries no metadata.