DESP

The DESP is the centre of the digital euro. It is where transactions actually settle, and it is the system a PSP's integration ultimately talks to.

Centralised, not distributed#

The single most common misconception about the digital euro is that it must be built on a blockchain. It is not. Settlement is centralised on the Eurosystem's DESP — a conventional, centrally operated platform. There is no distributed ledger, no consensus mechanism and no mining between PSPs.

Once you accept that, the integration stops looking exotic and starts looking familiar.

How PSPs integrate#

The DESP exposes JSON RESTful APIs. The data dictionary is ISO 20022-based, and the API patterns follow the Berlin Group style that European PSPs already know from PSD2 work. For contactless payments at the point of interaction, the CPACE standard applies.

In other words, the skill set required is ordinary payments engineering: REST, JSON, ISO 20022 semantics, and mutual authentication. The pilot's technical documentation is public on the ECB website, including back-end API specifications in YAML — so teams can read the actual contract rather than guess at it.

What the DESP owns#

Two responsibilities matter most when you are designing your side of the integration:

• Settlement. The transfer of digital euro between accounts happens here, not in your ledger.
• Identifiers. Every DEAN is generated by the Eurosystem through the DESP. A PSP requests an account and receives the identifier; it never allocates one itself.

That division is the whole architectural point. The PSP owns the customer relationship, onboarding, compliance and the user experience. The Eurosystem owns the money and the settlement. A distributing PSP is a distribution and servicing layer on top of a central platform it does not operate.