Back to Reference
Contents
Reference
491 words
Jun 25, 2026

Heratio Help Center article. Category: Federation.

Union catalogue (federated GLAM network)

Version: 1.0 Date: 2026-06-11 Author: The Archive and Heritage Group (Pty) Ltd

1. Overview

The union catalogue lets several institutions share their discovery metadata into one cross-institutional search. A visitor searches once at /union-catalogue and sees matching records from every participating institution, each result linking back to the record at its source catalogue.

Sharing is strictly opt-in and OFF by default. Nothing leaves your institution until an administrator turns sharing on. Only published records are shared, and you can require a minimum level of description as well. The union index holds discovery metadata only - title, level, dates, holding repository, and a permalink - never the full record.

This is a federation-discovery surface. It sits alongside the other federation publish surfaces (OAI-PMH at /oai, Europeana EDM at /federation/europeana).

2. Where to find it

  • Public search: /union-catalogue (anonymous, full-text ?q=).
  • Machine surface: /union-catalogue.json (CORS-open JSON, same ?q=).
  • Admin: Admin > Federation > Members (or directly at /federation/members).

3. Setting up sharing (administrators)

  1. Open /federation/members.
  2. Add a member for this institution and tick This institution. This is the self-member that owns the records you publish. Tick Include this member in union searches so your own records show up in the cross-member results.
  3. Add the other participating institutions as members. Tick Include this member in union searches for each one you want searchable.
  4. In Opt-in sharing, turn on Share this institution's records into the union catalogue. Leave Only share Published records ticked unless you have a reason not to. Optionally set a minimum level-of-description term id.
  5. Click Publish now (or let the daily 04:00 schedule run it). This runs ahg:federation-publish, which pushes your opt-in, published records into the union index. The run reports how many records were shared, how many were skipped, and why.

Turning sharing OFF stops future publishes. The publish command refuses to share anything while sharing is OFF or while no self-member is registered.

4. How records get into the index

The publish pass streams your published records in batches, applies the opt-in gate (sharing on, published-only, optional minimum level), and upserts each one into the union index keyed by member + record reference. Re-running is safe and idempotent - it refreshes existing rows rather than duplicating them.

5. Searching the union catalogue

Type a term and search. Results are grouped by institution and link to the source record. The JSON surface returns the same results as a flat record list for integrators. When no institutions have opted in yet, or there are no matches, the page shows a clear empty-state message rather than an error.

6. Privacy and scope

  • Opt-in, OFF by default. No record is shared without an administrator enabling it.
  • Published-only by default; draft and embargoed records are never shared.
  • Discovery metadata only - the index never holds the full record body.
  • Jurisdiction-neutral: the union catalogue makes no assumptions about any particular country's rules. Each institution decides what it shares.