Every Project in Relic is owned by exactly one tenant, and the tenantId is what records that ownership. It is the boundary that keeps each organization's archaeological data separate — when you view, search, or report on projects, you only ever see those whose tenantId matches your own tenant. You rarely set this by hand; Relic fills it in from your signed-in session. It also anchors the uniqueness rules on a Project, so two different tenants can each have a project named the same thing without colliding, because name and projectPrefix are only unique within a single tenantId.
Technical section
Data model, API, and internals — visible to developers.