Guide for MSBuild extensibility: CustomBefore/CustomAfter hooks, wildcard imports with alphabetic ordering, import gating with control properties, NuGet package build extension layout (build/buildTransitive), and the MicrosoftCommonPropsHasBeenImported guard. Only activate in MSBuild/.NET build context.
Install
npx skills add dotnet/skills --skill extension-pointsnpx skills add dotnet/skills --skill extension-points -a claude-code -gnpx skills add dotnet/skills --skill extension-points -a codex -ggemini skills install https://github.com/dotnet/skills.git --path plugins/dotnet-msbuild/skills/extension-pointsgh skill install dotnet/skills extension-pointsgit clone --depth 1 https://github.com/dotnet/skills /tmp/dotnet__skills
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/dotnet__skills/plugins/dotnet-msbuild/skills/extension-points ~/.claude/skills/extension-points # Claude Code
cp -R /tmp/dotnet__skills/plugins/dotnet-msbuild/skills/extension-points ~/.agents/skills/extension-points # Codex, Cursor, Gemini CLI, Copilot, OpenCode