AuthZed is the Authorization Platform for AI and modern applications, replacing homegrown and identity-bound permissions systems with a purpose-built, centralized service delivering extreme performance at global scale. AuthZed delivers sub-5ms permission checks and millions of queries per second to power critical applications for businesses like OpenAI, Workday, and Turo. AuthZed provides a single source of truth for permissions across all services, data, and users. Instead of embedding access logic throughout the codebase, teams define it once and enforce it everywhere. Our system is built on the same relationship-based model that powers Google, enabling fine-grained, dynamic access control at massive scale. It delivers low-latency permission checks, handles billions of relationships, and integrates with any identity provider or stack. The result is a shift in how authorization is built and operated, from bespoke, fragile infrastructure to a standardized, reliable platform, freeing teams to focus on their core product.