defense-in-depth

Enforce four-layer validation across entry points, business logic, environment, and debug instrumentation.

3|1|Updated Nov 5, 2025

Search Tags:#validation #defense-in-depth #robustness #data-integrity #software-quality #layers

Ready to run

npx skills add https://github.com/carlopezzuto/agents --skill defense-in-depth-carlopezzuto

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: defense-in-depth
Source: https://github.com/carlopezzuto/agents/tree/main/.claude/skills/defense-in-depth
Command: npx skills add https://github.com/carlopezzuto/agents --skill defense-in-depth-carlopezzuto

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Invalid data can propagate through multiple layers, causing failures deep in execution. This skill enforces validation at every layer to make bugs structurally impossible.

Core Features & Use Cases

Layer 1: Entry Point Validation to reject obviously wrong input at API boundaries.
Layer 2: Business Logic Validation to ensure data makes sense for operations.
Layer 3: Environment Guards to prevent dangerous actions in restricted contexts.
Layer 4: Debug Instrumentation to capture context for forensics and postmortems.

Quick Start

Validate a failing workflow by implementing the four-layer pattern: add entry validation, business-logic checks, environment guards, and debug instrumentation.

Frequently Asked Questions about defense-in-depth

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

What is multi-layer validation for preventing invalid data propagation?▼

You implement multi-layer validation by applying a four-layer pattern: entry point validation to reject bad input, business logic checks, environment guards, and debug instrumentation to capture context.

How do I stop invalid data from causing failures deep in execution?▼

You stop invalid data from causing deep execution failures by enforcing validation at every architectural layer. This approach rejects bad input early and ensures data makes sense before reaching core operations.

When should I use environment guards to restrict dangerous software actions?▼

You should use environment guards to prevent dangerous actions in restricted contexts. They act as the third layer of defense, ensuring your operations do not execute improperly in environments where they are unsafe.

How do I add debug instrumentation to capture data integrity context?▼

You add debug instrumentation as the fourth validation layer to capture context for forensics and postmortems. This helps trace exactly how invalid data bypassed earlier checks and entered your system.

Does entry point validation alone guarantee software robustness?▼

Entry point validation alone does not guarantee software robustness because invalid data can still emerge internally. You need layered validation including business logic checks and environment guards to make bugs structurally impossible.