Frictionless export

A reference for the export format. For tutorial coverage, see folio export.

Mapping table

The mapping from Folio’s contract attributes to Frictionless v1 fields:

Folio	Frictionless
`id`	top-level `name`
`name`	top-level `title`
`version`	top-level `version`
`description`	top-level `description`
`schema[0].name`	`resources[0].name`
`schema[0].physicalType`	`resources[0].format`
(records.jsonl)	`resources[0].path`
`schema[0].properties[].name`	`resources[0].schema.fields[].name`
`schema[0].properties[].logicalType`	`resources[0].schema.fields[].type` (mapped)
`schema[0].properties[].description`	`resources[0].schema.fields[].description`
`schema[0].properties[].required: true`	`resources[0].schema.fields[].constraints.required: true`
`schema[0].properties[].primaryKey: true`	`resources[0].schema.primaryKey: <name>`
`schema[0].properties[].x-derived: true`	`resources[0].schema.fields[].folioDerived: true`

logicalType → Frictionless type

Folio	Frictionless
`string`	`string`
`integer`	`integer`
`number`	`number`
`boolean`	`boolean`
`date`	`date`
`timestamp`	`datetime`
`array`	`array`
`object`	`object`

Frictionless’s time, geopoint, geojson, duration, year, yearmonth types have no Folio equivalent and are not produced.

What’s not exported

derivations/ files — Frictionless has no matching concept.
provenance.jsonl — Frictionless has no matching concept.
x-editable-by — Folio-specific; not exported.

The descriptor is a lossy projection. It’s enough for a Frictionless-aware tool to read the rows, but not enough to reconstruct the sheet from scratch.

Custom extension keys

Folio adds these custom keys (Frictionless tolerates unknown keys):

folioDerived: true — on a field’s object, marks it as a Folio derived field. External tools can choose to ignore the field on write.

Round-trip with `frictionless`

pip install frictionless
folio export datapackage ./customers
frictionless validate ./customers/datapackage.json
# ┌─────────────────────────────┬───────────┐
# │ ./customers/datapackage.json │ valid    │
# └─────────────────────────────┴───────────┘

frictionless is not a Folio dependency — install it on demand.

Future formats

folio export is namespaced by format. Today, only datapackage. The design overview §14.2 mentions OpenAPI surfaces and dbt model exports as future candidates; neither is implemented.