Shares authentication cookies between Katana/OWIN applications on ASP.NET Framework and ASP.NET Core applications during side-by-side migrations. Use when both hosts must accept the same cookie, when AspNetTicketDataFormat, DataProtectorShim, or Microsoft.Owin.Security.Interop is needed, or when users must remain signed in while routes move behind YARP or System.Web Adapters.
Install
npx skills add microsoft/upgrade-agent-plugins --skill sharing-authentication-cookies-katana-interopnpx skills add microsoft/upgrade-agent-plugins --skill sharing-authentication-cookies-katana-interop -a claude-code -gnpx skills add microsoft/upgrade-agent-plugins --skill sharing-authentication-cookies-katana-interop -a codex -ggemini skills install https://github.com/microsoft/upgrade-agent-plugins.git --path plugins/upgrade-agent/upgrade/dotnet/skills/lazy/web/mvc/sharing-authentication-cookies-katana-interopgh skill install microsoft/upgrade-agent-plugins sharing-authentication-cookies-katana-interopgit clone --depth 1 https://github.com/microsoft/upgrade-agent-plugins /tmp/microsoft__upgrade-agent-plugins
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/microsoft__upgrade-agent-plugins/plugins/upgrade-agent/upgrade/dotnet/skills/lazy/web/mvc/sharing-authentication-cookies-katana-interop ~/.claude/skills/sharing-authentication-cookies-katana-interop # Claude Code
cp -R /tmp/microsoft__upgrade-agent-plugins/plugins/upgrade-agent/upgrade/dotnet/skills/lazy/web/mvc/sharing-authentication-cookies-katana-interop ~/.agents/skills/sharing-authentication-cookies-katana-interop # Codex, Cursor, Gemini CLI, Copilot, OpenCode