# Type Safety Audit

> Audits TypeScript code for type safety best practices - no any usage, branded types for IDs, runtime validation, proper type narrowing. Use before committing TypeScript code or during type system reviews.

- Skill: `majiayu000/type-safety-audit` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add majiayu000/type-safety-audit`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/type-safety-audit/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- Author: majiayu000 (https://skillmd.com/u/majiayu000)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/majiayu000/type-safety-audit

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# TypeScript Type Safety Audit Skill

## Purpose

Audit TypeScript code for type safety best practices. This skill ensures the type system is leveraged correctly to catch bugs at compile-time, prevent runtime type errors, and maintain type safety across API boundaries.

## What This Skill Checks

### Critical Violations (Block Commit)

1. **Any Type Usage** - Zero tolerance policy
2. **Missing Branded Types** - IDs must be branded
3. **Missing Runtime Validation** - API boundaries need validation
4. **Type Assertions** - Prefer type guards
5. **Unsafe Null Handling** - Check for null/undefined
6. **Weak Generic Constraints** - Generics need constraints
7. **Non-Strict tsconfig** - Must have strict mode

**For detailed checks with code examples and rationale, see `references/CHECKS-REFERENCE.md`.**

- Hermes Code Reviewer: Type Safety Patterns