'Can Maria edit this document?' is a simple question with a hard implementation, and SpiceDB is the open-source, Zanzibar-inspired database built to answer it and millions like it correctly. You model your product once in its schema language, defining object types like documents and organizations, relations like owner and member, and computed permissions built from unions, intersections, exclusions, and arrows through other objects. Your application then writes relationships as users join groups, create folders, and share files, and SpiceDB evaluates checks against that live graph in milliseconds. Check a single permission before rendering a button, check hundreds at once to filter a dashboard, look up every resource a user can open for search prefiltering, or list every subject who can access a file for an admin screen. Per-request consistency options, anchored by revision tokens, protect you from the classic race where a revoked user briefly keeps access, and caveats add conditional rules based on context like IP address or time. Relationships persist in PostgreSQL for simple deployments or CockroachDB and Spanner when you need multi-region scale, and the same schema files validate in CI with the command-line tool before they ever reach production. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache-2.0 licensed.