defense-in-depth SKILL.md skillA
defense-in-depth from ed3dai/ed3d-plugins is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add ed3dai/ed3d-plugins/defense-in-depth@git:20260204.611bfd1Pins git:20260204.611bfd1 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- ed3dai/ed3d-plugins
- Path
plugins/ed3d-house-style/skills/defense-in-depth/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260204.611bfd1, committed Feb 4, 2026
- First version recorded
- Jan 15, 2026
- Size
- 4,760 bytes
- Repository stars
- 253
- License
- none declared
Use when invalid data causes failures deep in execution - validates at every layer data passes through to make bugs structurally impossible rather than temporarily fixed.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# 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.
## When to Use
**Use when:**
- Invalid data caused a bug deep in the call stack
- Data crosses system boundaries (API → service → storage)
- Multiple code paths can reach the same vulnerable code
- Tests mock intermediate layers (bypassing validation)
**Don't use when:**
- Pure internal function with single caller (validate at caller)
- Data already validated by framework/library you trust
- Adding validation would duplicate identical checks at adjacent layers
## The Four Layers
### Layer 1: Entry Point Validation
**Purpose:** Reject invalid input at API/system boundary
```typescript
function createProject(name: string, workingDirectory: string) {
if (!workingDirectory?.trim()) {
throw new Error('workingDirectory cannot be empty');
}
if (!existsSync(workingDirectory)) {
throw new Error(`workingDirectory does not exist: ${workingDirectory}`);
…Read the whole file at its exact version.
How to install
mdr add ed3dai/ed3d-plugins/defense-in-depth@sha256:9e807033e7dd7d8cThe line at the top of this page pins the label git:20260204.611bfd1, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_qf5bnx5ue4qbacen)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between Jan 15, 2026 and Feb 4, 2026, about one every 20 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260204.611bfd1 latest | 2026-02-04 | 611bfd1 | 4,760 B | A | view · diff |
| git:20260115.cf17c55 | 2026-01-15 | cf17c55 | 4,738 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (4760 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
ed3dai/ed3d-plugins · 253 stars · license none declared · pushed 2026-09-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_qf5bnx5ue4qbacen GET https://markdownregistry.com/api/v1/resolve?ref=ed3dai/ed3d-plugins/defense-in-depth GET https://markdownregistry.com/api/v1/blob/9e807033e7dd7d8c0b55169ccd8c4d634e4760ea1d56730e36cccf211ff9ed3d
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
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