Before the SDMX artefacts can be efficiently used in systems, it is essential that they are stored in a easily-maintainable and discoverable repository and they can be referenced in a standard, dependable manner - these features (and more) are available in an SDMX registry.

Therefore, the first step of the BUILD phase is to decide and implement the registries that will be used for the technical pilot and production phases.

There are several free, installable and cloud-based registry solutions available.  To learn about the SDMX registries that are available, start by searching for "registry" on SDMX.org: https://sdmx.org/?s=registry.

Unless the SDMX artefacts are meant for internal, non-public use only, the registry must be exposed publicly.  The pilot and production SDMX artefacts should ideally be stored in separate registries, especially to avoid non-final, test artefacts cluttering a production registry, especially such as the "global SDMX registry".

It is important to note that before an agency operates an SDMX registry, the agency should be registered in the SDMX Agency scheme to ensure that maintenance agencies are unique.  If a new registration is required, please contact hostmaster@registry.sdmx.org to request this.

At the end of this phase, the pilot and production registries will be decided, and at least the pilot registry should be implemented and made available for the next phase.