The SSH Open Marketplace (https://marketplace.sshopencloud.eu/), built as part of the Social Sciences and Humanities Open Cloud (SSHOC) project, is a discovery portal for the SSH research community comprising tools & services, training materials, datasets, publications and workflows. 

Designed as a catalogue contextualising its resources by creating links between them and showcasing their use in research scenarios (workflows), the interfaces of the SSH Open Marketplace are crucial for the discovery and reusability of its content. 

How does one build convenient, reliable, and accurate interfaces for a discovery portal? Which audiences (human, machines) and technologies have to be addressed by the interfaces and in which priority? What does it mean to be user-friendly for a web service in the world of research infrastructures? These are some of the questions we would like to discuss with the DARIAH Annual Event attendees. 

Three interface dimensions will guide our short demonstration of the beta version of the SSH Open Marketplace:

• The human individual interface dimension or user experience (UX) design and user interface (UI) (Graphical User Interface: https://marketplace.sshopencloud.eu/): SSH Open Marketplace is built to be a user-friendly portal designed on the principles of Human Center Designed (HCD) for the SSH community, with a low entry threshold for users' contributions. The design of the SSH Open Marketplace, developed by the Poznan Supercomputing and Networking Centre (PSNC) and implemented by the Austrian Centre for Digital Humanities and Cultural Heritage (ACDH-CH), has been built consulting target user communities. But still we seek for further feedback from the attendees of the demo session to identify possible improvements. 

• The machine-readable interface dimension or REST Application Programming Interface (API documentation:
  https://s.gwdg.de/pymPIp): the SSH Open Marketplace includes a REST API allowing experienced users to search and retrieve detailed information and even to add information. Particularly the last aspect would be of interest as to discuss how to provide easy means for adding new content to the marketplace using its API, which would likely be of interest for institutional users. A hackathon relying on some of the API functions is planned for September 2021, and our demo will also allow attendees to gain an overview of the hackathon tasks or to announce interest in taking part.

• The social-structural interface dimensions or gateway for SSH resources in the European Open Science Cloud (EOSC): https://marketplace.eosc-portal.eu/:  the SSH Open Marketplace is a contribution to the SSH branch of the EOSC, and as such it can be seen as a communication interface between the EOSC, its infrastructures and the SSH research communities interested in digital methods and practices. 

The demo session during the DARIAH Annual Event will touch upon all three and provoke a vivid discussion with the audience. We also hope to create a sense of awareness or ownership for the SSH Open Marketplace among the DARIAH and DH community as it is “their” service - a discovery portal for the SSH, in which they can add, curate, connect/contextualise and find the tools and services they need to complete and enhance their research.