This document provides an evaluation of the vision for, the delivered capabilities of, and the future prospects for \Acrshort{ESAP}, the \Acrlong{ESAP}.
\Acrshort{ESAP} is a key part of the interface between the services delivered by the \Acrshort{ESCAPE} project and the scientific community: it will provide a unified mechanism by which users can discover and interact with the data products, software tools, workflows, and services that are made available through \Acrshort{ESCAPE}, and it is designed to be extensible and flexible to adapt to the emergent requirements of future projects.
The development of \Acrshort{ESAP} has been the fundamental activity of \Acrshort{ESCAPE}\Acrlong{WP} 5.
\Acrshort{ESAP}, in and of itself, does not provide any compute or analysis capabilities.
Rather, it acts as a broker between users and the various services which are available to them.
For example, \Acrshort{ESAP} will help users identify datasets which are of interest to them (perhaps by interrogating the \Acrshort{ESCAPE} “data lake”, or an \Acrshort{ESFRI}-specific archive), to locate software and workflows which can help them analyze that data, and connect them to services which can execute analyses codes on their behalf (perhaps interactively, such as in a Jupyter notebook, or by scheduling jobs on a batch processing system).
\Acrshort{ESAP} abstracts the details of the various heterogeneous underlying systems from the user, so that they can use a unified, coherent interface to access all of the various services they need.
It does this by adopting a modular, flexible architecture.
The user will connect to a service-independent web-based \emph{user interface}, which in turn communicates with the \emph{\Acrshort{API} Gateway}.
By adopting a set of standard programming interfaces and conventions, the Gateway can easily be extended to address whatever current or future capabilities are exposed through the \Acrshort{EOSC}.
Over the course of the \Acrshort{ESCAPE} Project, \Acrshort{ESAP} has grown from a vision to a mature and usable software product, which can be immediately deployed in a range of scenarios.
Based on the material presented here, we conclude that \Acrshort{ESAP} has broadly achieved the goals that were set out at the beginning of the \Acrshort{ESCAPE} project, and is starting to see uptake in the \Acrshort{ESFRI} community.
It has also become clear that much of its potential remains to be tapped: major \Acrshort{ESFRI}s can build upon the systems delivered by \Acrshort{ESCAPE} to address the extreme requirements of the next generation of data- and compute-intensive infrastructures.
We look forward to seeing \Acrshort{ESAP} continue to grow as an open-source project even as the Horizon 2020 funding draws to a close.
This document is submitted as \Acrshort{ESCAPE} project deliverable \docNumber{}, \emph{\docTitle{}}.
