The digital euro high-level product design foresees the distribution of the digital euro solution to individuals via two main channels: (1) in the form of a dedicated mobile application, referred to as the “digital euro app” and (2) as an integrated solution within existing proprietary applications (e.g., Payment Service provider (PSP) app and online interface). The focus of this procurement procedure is the digital euro component that consists of the digital euro app and an integrated banking app software development kit (SDK). The digital euro app’s primary objectives are to establish a uniform and user-friendly interface through a homogeneous look and feel. Furthermore, the digital euro app shall ensure that all PSPs have equal access to end users and are able to distribute the digital euro in a consistent and efficient way without having to develop their own mobile application. This approach leverages economies of scale and reduces entry barriers for new or smaller PSPs that lack the resources to develop their own integration. The digital euro app is a thin-layer mobile application, primarily designed to serve as a front-end for the prioritised use cases, while the back-end digital euro related operations (such as transaction initiation or balance inquiries) will be handled by Payment Service Providers (PSPs). Providing this app ensures the availability of basic digital euro functionalities, as well as incorporating features supporting digital financial inclusion to cater for the needs of people with disabilities and those with low digital skills. Users can utilise the digital euro app to interact with their chosen PSP via their smart device (e.g., smartphone, tablet, or wearable), for example to display information or initiate payments. In addition to the digital euro app, the Eurosystem will provide a SDK to support PSPs in the provision of digital euro services through their own mobile apps. The SDK is a software development kit that helps PSPs to integrate digital euro services into their own existing mobile apps and online interfaces. The SDK is embedded in the PSP’s mobile banking apps as a software library and provides, among other things, a client to the digital euro standard APIs provided by the DESP. At a high level, the digital euro app & SDK consist of (non-exhaustive list): The front-end of the digital euro app, which provides entry points for various digital euro online and offline functionalities and services. On the initial launch of the digital euro app, users will be prompted to choose their PSP, configuring the digital euro app to use the selected PSP's API endpoints for back-end communication; and Entry points (i.e., SDK) to API interfaces. These allow the integrated front-end to connect to the PSPs back-end systems. The digital euro app & SDK shall be usable on a range of smart devices including, but not limited to, smartphones, tablets and smartwatches. The SDK shall be compatible with payment and mobile banking apps as well as online interfaces of PSPs operating in the euro area. On the other hand, the digital euro app shall be available for download from the official application stores of at least the Android and iOS platforms. Additionally, the digital euro app shall offer backward compatibility, ensuring it can run on older versions of the Android and iOS platforms that are still within the manufacturer's support cycle. This call for applications seeks the party responsible for the development, including maintenance, as well as the operation of the digital euro app & SDK component for the digital euro based on the relevant contractual arrangements and on a decision of the ECB Governing Council.