Consolidate repeated system instructions into a stable prompt prefix when configuring an application's prompt caching.
Install
npx skills add alivirgo/Major-AI-Skills --skill avoid-duplicate-system-messagesnpx skills add alivirgo/Major-AI-Skills --skill avoid-duplicate-system-messages -a claude-code -gnpx skills add alivirgo/Major-AI-Skills --skill avoid-duplicate-system-messages -a codex -ggemini skills install https://github.com/alivirgo/Major-AI-Skills.git --path skills/avoid-duplicate-system-messagesgh skill install alivirgo/Major-AI-Skills avoid-duplicate-system-messagesgit clone --depth 1 https://github.com/alivirgo/Major-AI-Skills /tmp/alivirgo__Major-AI-Skills
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/alivirgo__Major-AI-Skills/skills/avoid-duplicate-system-messages ~/.claude/skills/avoid-duplicate-system-messages # Claude Code
cp -R /tmp/alivirgo__Major-AI-Skills/skills/avoid-duplicate-system-messages ~/.agents/skills/avoid-duplicate-system-messages # Codex, Cursor, Gemini CLI, Copilot, OpenCode