Heratio Help Center article. Category: Metadata Export.

CIDOC-CRM (Metadata Export)

Version: 1.0 Date: 2026-06-11 Author: Plain Sailing Information Systems

What it does

This exporter, part of the Metadata Export dashboard, emits Heratio entities as CIDOC Conceptual Reference Model (CIDOC-CRM / ISO 21127) RDF documents. CIDOC-CRM is the de-facto interoperability ontology for cultural heritage, used by ResearchSpace, the Erlangen-CRM importer, Getty Linked Open Data and most museum aggregator pipelines.

It now covers all three core G/L/A/M entity types - records, actors and terms / places - so a Heratio holding can be published to a CRM consumer as a joined graph of objects, the people and bodies who made them, and the subjects and places they describe. Each document references the others by URI, so they slot together in one triple store.

It is a sibling of the RiC-bridge CIDOC-CRM export (see "CIDOC-CRM Export"). The key difference is that this exporter models the creation chain as an explicit crm:E12_Production event rather than flattening it onto the object, so the production - actor - time-span relationship is expressed as first-class CRM:

E22 Human-Made Object
  - P108i was produced by - E12 Production
                              E12 - P14 carried out by - E39/E21/E40/E74 Actor
                              E12 - P4 has time-span   - E52 Time-Span

It is one of the slices of the unified G/L/A/M knowledge graph (RiC + CIDOC-CRM + KM, issue #1197).

Endpoints

There is one endpoint family per entity type. All share the same format negotiation (Turtle by default, RDF/XML via ?rdf=rdf or a .rdf extension) and all live under /admin/metadata-export:

# record
GET /admin/metadata-export/cidoc-crm?io={id}
GET /admin/metadata-export/cidoc-crm.ttl?io={id}
GET /admin/metadata-export/cidoc-crm.rdf?io={id}

# actor (person / corporate body / family)
GET /admin/metadata-export/cidoc-crm-actor?actor={id}
GET /admin/metadata-export/cidoc-crm-actor.ttl?actor={id}
GET /admin/metadata-export/cidoc-crm-actor.rdf?actor={id}

# term / place (place taxonomy -> E53 Place, else E55 Type)
GET /admin/metadata-export/cidoc-crm-term?term={id}
GET /admin/metadata-export/cidoc-crm-term.ttl?term={id}
GET /admin/metadata-export/cidoc-crm-term.rdf?term={id}

The path extension wins over ?rdf= when both are present.

Examples

Turtle (default):

curl 'https://heratio.example.org/admin/metadata-export/cidoc-crm?io=42'

RDF/XML:

curl 'https://heratio.example.org/admin/metadata-export/cidoc-crm.rdf?io=42'

What is in the document

For every record the export emits:

• The object node typed crm:E22_Human-Made_Object, with rdfs:label, crm:P102_has_title (to an E35 Title node), crm:P1_is_identified_by (to an E42 Identifier node) and crm:P3_has_note (scope and content, extent).
• crm:P108i_was_produced_by to a single crm:E12_Production node when the record has creators or dated creation events.
• On the E12 Production node: one crm:P14_carried_out_by per creator actor and one crm:P4_has_time-span per dated creation event.
• One Actor node per creator, typed crm:E21_Person / crm:E40_Legal_Body / crm:E74_Group / crm:E39_Actor based on the actor's entity type.
• crm:P50_has_current_keeper to an crm:E40_Legal_Body repository node.
• crm:P129_is_about to crm:E1_CRM_Entity nodes for subject access points.
• crm:P67_refers_to to crm:E53_Place nodes for place access points.
• crm:P72_has_language to crm:E56_Language nodes for language access points.
• crm:E52_Time-Span nodes per dated creation event, carrying crm:P82a_begin_of_the_begin and crm:P82b_end_of_the_end as xsd:date.

The default namespace is the official CIDOC ns (http://www.cidoc-crm.org/cidoc-crm/); the Erlangen CRM (http://erlangen-crm.org/current/) is declared as the ecrm: alias so Erlangen-based tooling resolves the same local names.

What is in an actor document

For an actor (?actor={id}):

• The actor node typed by entity type: crm:E21_Person (person), crm:E40_Legal_Body (corporate body), crm:E74_Group (family), or crm:E39_Actor when the type is unknown.
• crm:P1_is_identified_by to a crm:E82_Actor_Appellation node carrying the authorized form of name.
• crm:P3_has_note for the actor history.
• An existence crm:E52_Time-Span when dates exist: for a person via a crm:E67_Birth event (P98_brought_into_life + P4_has_time-span), for other types via a direct P4_has_time-span. The span carries crm:P82a_begin_of_the_begin / crm:P82b_end_of_the_end (xsd:date) and the display dates label.
• crm:P11i_participated_in to the crm:E12_Production of each record the actor created - the same production URI the record export mints, so the two documents join.

What is in a term / place document

For a term (?term={id}). A term in the Places taxonomy maps to crm:E53_Place; any other taxonomy (subjects, genres) maps to crm:E55_Type:

• crm:P1_is_identified_by to a crm:E48_Place_Name (places) or crm:E41_Appellation (types) appellation node.
• Hierarchy: places use crm:P89_falls_within (parent) and crm:P89i_contains (children); types use crm:P127_has_broader_term and crm:P127i_has_narrower_term.
• Records that cite the term, via the inverse of the record export's forward link: places use crm:P67i_is_referred_to_by; types use crm:P129i_is_subject_of. Each points at the record's #crm-object node.

Formats

• Turtle (text/turtle) - default; compact, good for human review and git diffs.
• RDF/XML (application/rdf+xml) - for CRM tooling (ResearchSpace, Apache Jena, Erlangen importer).

Both express the same graph.

Authentication and visibility

The dashboard endpoint sits behind the web + auth middleware - authenticated staff can export any record, including unpublished ones, for review. The serializer additionally carries a published-records gate (status.type_id = 158 AND status.status_id = 160, root record id = 1 excluded) that any future unauthenticated Linked Data surface can opt into so only published records are exposed publicly.

The actor and term endpoints carry the same published-records gate on their linked-record lists, so a public surface that opts in never exposes a draft record title through an actor's produced works or a term's citations.

Read-only

The exporter only reads the database. It never writes, alters or migrates any table, and leaves the existing exporters (DACS, MODS, RAD, dcterms, EAD, EAC, MARC) and the existing record CIDOC-CRM export untouched. The actor and term serializers are new files; they reuse the record serializer's rendering through a shared trait so the three CRM surfaces produce identical Turtle / RDF/XML.

Troubleshooting

• 404 "No record produced": the io id does not resolve to an information_object row in the supplied culture. Supply ?culture=en or translate the record.
• Empty Production block: no creation event (type_id = 111) ties an actor to the record and no dated creation event exists. Add a creator or a date.
• Empty Time-Span block: the creation events carry no start_date / end_date / date_display. Add at least one.

Related articles

• "CIDOC-CRM Export" - the RiC-bridge per-record CRM exporter (E73-centred).
• "RiC Dashboard User Guide" - Heratio's RiC-O CRUD surface.