Validate at every layer data passes through to make bugs impossible. Use when invalid data causes failures deep in execution, requiring validation at multiple system layers.
Installs just this skill. Get the whole plugin for auto-invocation.
⚡ How it fires
How this skill gets triggered: by you, by Claude, or both.
Fires itselfClaude auto-loads it when your prompt matches the work.
You can call itInvoke it directly when you want it.
Slash command/defense-in-depth-validation
👁️ Context preview
The summary Claude sees to decide when to auto-load this skill.
Validate at every layer data passes through to make bugs impossible. Use when invalid data causes failures deep in execution, requiring validation at multiple system layers.
📊 Stats
Stars194
Forks29
LanguageTypeScript
LicenseMIT
📦 Ships with claude-skills
</> SKILL.md
defense-in-depth-validation.SKILL.md
---name: defense-in-depth-validation
description: Validate at every layer data passes through to make bugs impossible. Use when invalid data causes failures deep in execution, requiring validation at multiple system layers.
metadata:
version: "1.1.0"
license: MIT
---# Defense-in-Depth Validation
## Overview
When you fix a bug caused by invalid data, adding validation at one place feels sufficient. But that single check can be bypassed by different code paths, refactoring, or mocks.
**Core principle:** Validate at EVERY layer data passes through. Make the bug structurally impossible.
## Why Multiple Layers
Single validation: "We fixed the bug"
Multiple layers: "We made the bug impossible"
Different layers catch different cases:
- Entry validation catches most bugs
- Business logic catches edge cases
- Environment guards prevent context-specific dangers
- Debug logging helps when other layers fail
## The Four Layers
### Layer 1: Entry Point Validation
**Purpose:** Reject obviously invalid input at API boundary
```typescript
function createProject(name: string, workingDirectory: string) {
