CommunityToolkit.Mvvm Messenger pub/sub for decoupled communication between ViewModels (or any objects). Covers WeakReferenceMessenger vs StrongReferenceMessenger, IRecipient<TMessage>, RequestMessage<T> / AsyncRequestMessage<T> / CollectionRequestMessage<T>, ValueChangedMessage<T>, channels (tokens), and the ObservableRecipient activation lifecycle.
Install
npx skills add github/awesome-copilot --skill mvvm-toolkit-messengernpx skills add github/awesome-copilot --skill mvvm-toolkit-messenger -a claude-code -gnpx skills add github/awesome-copilot --skill mvvm-toolkit-messenger -a codex -ggemini skills install https://github.com/github/awesome-copilot.git --path skills/mvvm-toolkit-messengergh skill install github/awesome-copilot mvvm-toolkit-messengergit clone --depth 1 https://github.com/github/awesome-copilot /tmp/github__awesome-copilot
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/github__awesome-copilot/skills/mvvm-toolkit-messenger ~/.claude/skills/mvvm-toolkit-messenger # Claude Code
cp -R /tmp/github__awesome-copilot/skills/mvvm-toolkit-messenger ~/.agents/skills/mvvm-toolkit-messenger # Codex, Cursor, Gemini CLI, Copilot, OpenCode