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MEF is a linked entity hub that aggregates and aligns authority records from VIAF, IdRef, GND, and RERO. It provides a unified, stable identifier for persons, organisations, concepts, and places across multiple source systems — making multilingual metadata reuse seamless for integrated library systems and data pipelines. Records are harvested automatically and kept in sync with their upstream sources.

Explore the entities

Agents
2,566,013 records
Persons and organisations linked across VIAF, IdRef, GND, and RERO.
Browse Agents API for Agents (opens in a new window)
Concepts
432,448 records
Subject headings and thematic terms aligned across sources.
Browse Concepts API for Concepts (opens in a new window)
Places
7,158 records
Geographic entities with cross-source identifiers.
Browse Places API for Places (opens in a new window)

How MEF works

VIAF
IdRef
GND
RERO

Learn how linking works

Step 1: Harvest
Authority records are harvested automatically from each source.
Step 2: Align
Records describing the same entity are aligned into a single MEF record.
Step 3: Identify
Each entity gets a stable MEF identifier, kept in sync with its sources.

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