Authorization Policy-as-Code Engines

Casbin is an authorization library that provides a model-based engine for enforcing access control across diverse application environments. It decouples authorization logic from application code by using a configuration-driven approach, allowing developers to define access rules and evaluation logic independently. The system supports a wide range of access control models, including role-based, attribute-based, and relationship-based patterns, which are evaluated at runtime to determine if a subject is permitted to perform an action on a resource. The project distinguishes itself through a hig

This project is a unified, cloud-native policy engine designed to decouple authorization and security logic from application codebases. It functions as a centralized authorization service that evaluates structured input data against declarative rules, enabling consistent policy enforcement across microservices, infrastructure, and continuous integration pipelines. The engine utilizes a specialized logic programming language to express complex constraints, which are compiled into an optimized intermediate representation for high-performance evaluation. By supporting both sidecar-based deployme

OpenFGA is a fine-grained authorization server and policy decision point that implements relationship-based access control. It serves as a centralized authorization service for evaluating access requests and managing relationship tuples across distributed microservices and multi-tenant environments. The engine combines relationship graphs with attribute-based access control, using the Common Expression Language to evaluate dynamic runtime attributes and conditional access rules. It handles complex hierarchies and nested permissions by traversing chains of associations and parent-child links t

Cerbos is an open-source authorization service that provides a centralized, language-agnostic engine for managing access control. It functions as a policy-as-code platform, allowing teams to define, test, and distribute authorization rules using declarative YAML or JSON configurations. By decoupling access logic from application code, it enables consistent permission enforcement across diverse service stacks. The project distinguishes itself through its ability to translate high-level authorization policies into native database query filters. This capability allows applications to enforce sec

Casbin is an authorization library designed to manage application access control and permissions through a configurable model-based engine. It serves as a centralized system for verifying whether a user has permission to perform specific actions on a resource. The engine supports multiple access control models, including Role-Based Access Control, Attribute-Based Access Control, and Access Control Lists. It allows for the definition of role hierarchies and the evaluation of user, resource, and environment attributes to make access decisions. The library decouples authorization logic from dat

Ory Keto is an open-source authorization server that implements Google Zanzibar’s relationship-based access control model. It stores every access relationship as a tuple in a SQL database and exposes a declarative TypeScript-like namespace language for defining object types, relations, and permissions. The service provides bidirectional permission resolution, configurable consistency levels for checks, and dual gRPC and REST APIs for broad integration. Keto extends the Zanzibar model with edge enforcement of access policies, structured compliance auditing of permission decisions, and infrastr