IdentityServer is a free, open source OpenID Connect and OAuth 2.0 framework for ASP.NET Core. Founded and maintained by Dominick Baier and Brock Allen, IdentityServer4 incorporates all the protocol implementations and extensibility points needed to integrate token-based authentication, single-sign-on and API access control in your applications. IdentityServer4 is officially certified by the OpenID Foundation and thus spec-compliant and interoperable. It is part of the .NET Foundation, and operates under their code of conduct. It is licensed under Apache 2 (an OSI approved license).
For project documentation, please visit readthedocs.
Active development happens on the master branch. This always contains the latest version. Each (pre-) release is tagged with the corresponding version. The aspnetcore1 and aspnetcore2 branches contain the latest versions of the older ASP.NET Core based versions.
IdentityServer is built against the latest ASP.NET Core 3.
For project documentation, please visit readthedocs.
See here for the 1.x docs, and here for the 2.x docs.
Please use the issue tracker for that. We only support the latest version for free. For older versions, you can get a commercial support agreement with us.
If you need help with implementing IdentityServer4 or your security architecture in general, there are both free and commercial support options. See here for more details.
If you are a fan of the project or a company that relies on IdentityServer, you might want to consider sponsoring. This will help us devote more time to answering questions and doing feature development. If you are interested please head to our Patreon page which has further details.
Thinktecture AG
Ritter Insurance Marketing
Intuit
ExtraNetUserManager
You can see a list of our current sponsors here - and for companies we have some nice advertisement options as well.
IdentityServer4 is built using the following great open source projects and free services:
..and last but not least a big thanks to all our contributors!