You can find all source code for IdentityServer and its supporting repos in our organization.
Standard support and feature requests are handled via our public support forum. Please start a discussion there if you need help.
Priority support is part of our Enterprise Edition, or can be purchased separately. It includes a private email alias, guaranteed two US business days response time and two private incidents per year. Please contact us for more information.
See here for our support policy.
Security issues and bugs should be reported privately here. You should receive a response within 24 hours.