Security skills for AI coding assistants and agentic systems. Skills encode security recommendations, guidelines, and best practices as structured markdown files that AI assistants (Claude Code, Cursor, Copilot, and others) consume directly while writing, testing, and auditing code. The goal is to shift security left: apply security guidance during development, not after review. Get started Installs ruff, ty, pre-commit, and wires up git hooks so linting and ADR validation run automatically before each commit. Requires uv on your PATH. Using a skill Reference any skill by path in your assistant prompt: Using `module/skills/input-output-sanitization/SKILL.md`: review this MCP server for injection risks. Using `module/skills/cargo-fuzz/SKILL.md`: write a fuzzing harness for this parser. Using `module/skills/differential-review/SKILL.md`: review the security impact of this diff. Skills are tool-agnostic — the same files work in any assistant that can read them.…