This project is not maintained anymore and is now archived.
IdentityServer4 is a free, open source OpenID Connect and OAuth 2.0 framework for ASP.NET Core. It went out of support when .NET Core 3.1 end of support was reached (13th Dec 2022).
Originally founded and maintained by Dominick Baier and Brock Allen, the IdentityServer4 project was forked as Duende IdentityServer and is now maintained and supported as a commercial product with a Community Edition available.
IdentityServer4 contains multiple known security vulnerabilities and bugs, and has outdated documentation. As explained in more detail on the Duende blog, the decision was made to archive the IdentityServer4 repository and code in the current DuendeArchive GitHub organization.
Issues are read-only and can still be consulted. The IdentityServer4 code is available in the archive branch:
git clone https://github.com/DuendeArchive/IdentityServer4.git
git checkout archiveIdentityServer4 is licensed under Apache 2 (an OSI approved license).