OpenIddict is a flexible OAuth 2.0 and OpenID Connect stack for .NET that enables client, server, and token validation support across ASP.NET and ASP.NET Core applications, with client capabilities also available on Android, iOS, and desktop platforms.
The tool addresses the need to implement standards-compliant identity and authorization infrastructure in .NET applications. It supports multiple OAuth 2.0 and OpenID Connect flows including code, implicit, and hybrid flows, as well as client credentials, resource owner password grants, device authorization, and token exchange. The framework integrates natively with Entity Framework Core, Entity Framework 6, and MongoDB for data persistence, while allowing custom store implementations for other backends.
Developers should adopt OpenIddict if they need fine-grained control over their OAuth 2.0 and OpenID Connect implementation and are willing to write custom code to achieve it. The tool suits organizations building custom identity providers rather than those seeking a turnkey solution. The README explicitly recommends Volo.OpenIddict.Pro for developers prioritizing simplicity and a management GUI over customization. OpenIddict is not a certified implementation; instead, developers are expected to run conformance tests against their own deployments to ensure standards compliance.
The project maintains active development with regular updates to its core components and integrations. Documentation is comprehensive and includes dedicated guides for getting started. Sample implementations demonstrating various OAuth 2.0 and OpenID Connect flows are maintained in a separate repository to help developers understand integration patterns. The maintainers acknowledge the framework's nature as a customizable foundation rather than a complete product, positioning it appropriately for teams with specific identity requirements.
