defense-in-depth SKILL.md skillA
defense-in-depth from event4u-app/agent-config is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add event4u-app/agent-config/defense-in-depth@git:20260711.0f04776Pins git:20260711.0f04776 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- event4u-app/agent-config
- Path
src/skills/defense-in-depth/SKILL.md- Versions recorded
- 3
- Latest version
- git:20260711.0f04776, committed Jul 11, 2026
- First version recorded
- Jun 3, 2026
- Size
- 6,205 bytes
- Repository stars
- 19
- License
- MIT
Use when validation needs entry, business-logic, environment, and instrumentation guards so a bad value cannot reach the failure point — turns a local bug fix into a structural one.
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 Validate at every layer the value passes through. Fixing the bug at one layer is locally sufficient and globally fragile — the next refactor, code path, mock, or platform edge case will rediscover it. Four-layer validation makes the bug *structurally* impossible. ## When to use - Bug fix where invalid data caused failure several frames deep. - New entry point that funnels external input into existing internals. - Refactor that adds a second caller to a previously single-caller routine. - Test setup that shortcuts production guards (mocks bypassing entry validation). Do NOT use when: - Pure formatting / style change — no data flow, no layers to defend. - Boundary validation alone is correct (e.g. immutable value object with constructor invariant) — route to [`laravel-validation`](../laravel-validation/SKILL.md). - The fix belongs at a single architectural seam — adding three more guards is over-engineering. Use the gate function below to stop early. ## Procedure: Apply the four-layer pattern ### Step 0: Analyze the data flow before adding guards 1. Identify where the bad value originates (test fixture, request body, env var, config). …
Read the whole file at its exact version.
How to install
mdr add event4u-app/agent-config/defense-in-depth@sha256:d8bdc8e520d640cdThe line at the top of this page pins the label git:20260711.0f04776, 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_wnpjey5lmyuhi2vo)
5 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 3 versions of this file, between Jun 3, 2026 and Jul 11, 2026, about one every 19 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260711.0f04776 latest | 2026-07-11 | 0f04776 | 6,205 B | A | view · diff |
| git:20260613.3248611 | 2026-06-13 | 3248611 | 6,170 B | A | view · diff |
| git:20260603.668ed88 | 2026-06-03 | 668ed88 | 6,250 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 (6205 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
event4u-app/agent-config · 19 stars · license MIT · pushed 2026-11-05 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_wnpjey5lmyuhi2vo GET https://markdownregistry.com/api/v1/resolve?ref=event4u-app/agent-config/defense-in-depth GET https://markdownregistry.com/api/v1/blob/d8bdc8e520d640cd04fcec17da7200c2069da0c9e35fb6bfd019011ddec03ef2
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.
More from event4u-app/agent-config
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