  Central banks are actively exploring central bank digital currencies (CBDCs)
by conducting research, proofs of concept and pilots. However, adoption of a
CBDC can risk fragmenting both payments markets and retail deposits. In this
paper, we aim to provide a mitigation to this fragmentation risk by presenting
an illustrative industry architecture which places CBDCs and commercial bank
money on a similar footing. We introduce the concept of ecosystems providing a
common programmability layer that interfaces with the account systems at both
commercial banks and the central bank. We focus on a potential United Kingdom
(UK) CBDC, including industry ecosystems interfacing with commercial banks
using Open Banking application programming interfaces (APIs).
