A workspace is the container for your links, QR codes, pages, domains, members and analytics. Each account has one workspace of its own and can be invited to others; an API key belongs to exactly one. Roles are Owner, Admin, Editor and Viewer — see GET /v1/members.
Every live workspace can have a paired test workspace (is_test: true) with its own uc_test_ keys and data. Test links are never served on crop.sh or your domains (section 12).
Short link host. A workspace object carries short_link_host, the host new short URLs show for the default domain, and, only while URLCrop offers a backup short domain (for example go.crop.sh), short_host_alt. Both are read-only. short_host_preference (alt or primary) is the choice you make with PATCH /v1/workspaces/{id} (Owner or Admin, session). It changes only the host shown on new short URLs; stored links keep their domain, existing QR codes keep the address they were created with, and both hosts redirect.