The SDMX Global Discovery Service (GDS) is a central catalogue of SDMX-compliant web services.

It acts as the authoritative directory that links each SDMX Agency to the official web services where that agency’s metadata is published.

Purpose

Without the GDS, applications would need to know and maintain the service locations for each agency individually.

The GDS solves this by providing a single entry point for discovery, ensuring that metadata always comes from the authoritative source.

How It Works

When a client application sends a URN to the URN Resolver, the following steps occur:

1. The Resolver extracts the agency identifier from the URN (e.g. ESTAT).
2. The Resolver requests the service locations from the GDS to find the official list of SDMX web services registered for that agency.
3. The Resolver checks which of the registered services actually provides the requested structure.
4. The Resolver returns the authoritative structure to the client, in the format requested by the client.

This process guarantees:

• URNs resolve consistently, without relying on unofficial or duplicate sources.
• Clients can request the structure in their preferred format, even if the agency’s web service does not natively provide it.

Registration in GDS

• Top-level agencies can register their web services in the GDS.
• Registration ensures that their published metadata is discoverable and resolvable through the URN Resolver.
• Agencies may register multiple service endpoints if needed, for example some structure may appear in the SDMX Global Registry, with others in a Agency specific service

Example Workflow

A URN such as:

urn:sdmx:org.sdmx.infomodel.codelist.Codelist=ESTAT:CL_ACTIVITY(1.0)

• Contains the agency identifier ESTAT.
• The Resolver requests the service location(s) for ESTAT from the GDS.
• The GDS responds with the list of official Eurostat service endpoints.
• The Resolver queries Eurostat’s registered endpoint(s) until it finds the requested structure
• The Resolver writes the authoritative CL_ACTIVITY structure that it received from the ESTAT service in the format requested by the client

Further Information

More details on the GDS are availble on browser.sdmx.io.

Explore the GDS catalogue via gds.sdmx.io