The main challenge of the COVID-X Sandbox is to integrate healthcare datasets from various sources. These datasets are characterized by multiple types of heterogeneity. Fully anonymized data will be available to be collected in various formats through multiple different methods. These data must be curated, harmonized, annotated, and structurally and semantically enriched to feed third-party applications and services. The current deliverable presents the design, architecture, and internal services of the COVID-X Sandbox.