Defensive programming for any code: validating inputs at every boundary, checking for null and absent values, supplying safe fallbacks, catching and logging exceptions, and degrading gracefully rather than failing. Use when someone asks to make code robust, resilient, safer, or harder to crash. Routes to the sub-skill matching the kind of work.
Install
npx skills add rainmanjam/poka-yoke --skill defensivenpx skills add rainmanjam/poka-yoke --skill defensive -a claude-code -gnpx skills add rainmanjam/poka-yoke --skill defensive -a codex -ggemini skills install https://github.com/rainmanjam/poka-yoke.git --path benchmarks/controls/defensive/skills/defensivegh skill install rainmanjam/poka-yoke defensivegit clone --depth 1 https://github.com/rainmanjam/poka-yoke /tmp/rainmanjam__poka-yoke
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/rainmanjam__poka-yoke/benchmarks/controls/defensive/skills/defensive ~/.claude/skills/defensive # Claude Code
cp -R /tmp/rainmanjam__poka-yoke/benchmarks/controls/defensive/skills/defensive ~/.agents/skills/defensive # Codex, Cursor, Gemini CLI, Copilot, OpenCode