Hardens code against vulnerabilities. Use when handling user input, authentication, data storage, or external integrations. Use when building any feature that accepts untrusted data, manages user sessions, or interacts with third-party services.
Install
npx skills add addyosmani/agent-skills --skill security-and-hardeningnpx skills add addyosmani/agent-skills --skill security-and-hardening -a claude-code -gnpx skills add addyosmani/agent-skills --skill security-and-hardening -a codex -ggemini skills install https://github.com/addyosmani/agent-skills.git --path skills/security-and-hardeninggh skill install addyosmani/agent-skills security-and-hardeninggit clone --depth 1 https://github.com/addyosmani/agent-skills /tmp/addyosmani__agent-skills
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/addyosmani__agent-skills/skills/security-and-hardening ~/.claude/skills/security-and-hardening # Claude Code
cp -R /tmp/addyosmani__agent-skills/skills/security-and-hardening ~/.agents/skills/security-and-hardening # Codex, Cursor, Gemini CLI, Copilot, OpenCode