Best OpenFGA Alternatives

SpiceDB is an open-source authorization database inspired by Google's Zanzibar system, providing relationship-based access control (ReBAC) at scale. It defines permissions through a schema language that models relationships between users, resources, and roles, then evaluates authorization checks in single-digit milliseconds. Used by companies like Netflix and GitHub, SpiceDB handles millions of permission checks per second.

Ory provides a suite of modular open-source identity components: Kratos for user management and authentication, Hydra for OAuth2 and OIDC, Oathkeeper for API gateway authorization, and Keto for fine-grained permission management. Used by OpenAI and other major organizations. API-first design with Go-based microservices that deploy independently or together as Ory Network cloud.