security-and-hardening SKILL.md skillA

security-and-hardening from lll0k0lad/agent-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

mdr add lll0k0lad/agent-skills/security-and-hardening@git:20260215.46f377a

Pins git:20260215.46f377a in mdr.lock. Pin the fingerprint instead.

Audit grade

A, 17 of 17 checks passed

Kind

SKILL.md skill

Repository

lll0k0lad/agent-skills

Path

skills/security-and-hardening/SKILL.md

Versions recorded

1

Latest version

git:20260215.46f377a, committed Feb 15, 2026

Size

9,913 bytes

Repository stars

3

License

MIT

Use when handling user input, authentication, data storage, or external integrations. Use when building any feature that accepts untrusted data, manages user sessions, or interacts with third-party services.

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

# Security and Hardening

## Overview

Security-first development practices for web applications. Treat every external input as hostile, every secret as sacred, and every authorization check as mandatory. Security isn't a phase — it's a constraint on every line of code that touches user data, authentication, or external systems.

## When to Use

- Building anything that accepts user input
- Implementing authentication or authorization
- Storing or transmitting sensitive data
- Integrating with external APIs or services
- Adding file uploads, webhooks, or callbacks
- Handling payment or PII data

## The Three-Tier Boundary System

### Always Do (No Exceptions)

- **Validate all external input** at the system boundary (API routes, form handlers)
- **Parameterize all database queries** — never concatenate user input into SQL
- **Encode output** to prevent XSS (use framework auto-escaping, don't bypass it)
- **Use HTTPS** for all external communication
- **Hash passwords** with bcrypt/scrypt/argon2 (never store plaintext)
- **Set security headers** (CSP, HSTS, X-Frame-Options, X-Content-Type-Options)
- **Use httpOnly, secure, sameSite cookies** for sessions
…

Read the whole file at its exact version.

How to install

mdr add lll0k0lad/agent-skills/security-and-hardening@sha256:ae798cb362743e0a

[![mdr](https://markdownregistry.com/badge/art_wkeqjugereeyewes.svg)](https://markdownregistry.com/a/art_wkeqjugereeyewes)

Versions

The registry has recorded 1 version of this file, committed on Feb 15, 2026.

Audit of the latest version

Source

API

GET https://markdownregistry.com/api/v1/artifacts/art_wkeqjugereeyewes
GET https://markdownregistry.com/api/v1/resolve?ref=lll0k0lad/agent-skills/security-and-hardening
GET https://markdownregistry.com/api/v1/blob/ae798cb362743e0a89258c8a891e24b973a994cef547372a2dae1cddf5a64319

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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