Use when the user asks to establish shared project language, or project work exposes a conflicting, renamed, or deprecated domain term that needs active semantic modeling. Routine small tasks stay on the fast path.
Install
npx skills add GanyuanRan/Aegis --skill establishing-project-contextnpx skills add GanyuanRan/Aegis --skill establishing-project-context -a claude-code -gnpx skills add GanyuanRan/Aegis --skill establishing-project-context -a codex -ggemini skills install https://github.com/GanyuanRan/Aegis.git --path skills/establishing-project-contextgh skill install GanyuanRan/Aegis establishing-project-contextgit clone --depth 1 https://github.com/GanyuanRan/Aegis /tmp/GanyuanRan__Aegis
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/GanyuanRan__Aegis/skills/establishing-project-context ~/.claude/skills/establishing-project-context # Claude Code
cp -R /tmp/GanyuanRan__Aegis/skills/establishing-project-context ~/.agents/skills/establishing-project-context # Codex, Cursor, Gemini CLI, Copilot, OpenCode