Public upstreamAddy OsmaniPublic source

Addy Osmani application hardening

Review inputs, sessions, permissions, secrets and dependencies in a web application.

Workflow

Addy Osmani’s security skill covers web application trust boundaries, authentication, authorization, data handling, dependency findings and external integrations.

Use when

Implement or review web features that handle untrusted data or user sessions.

Required inputs

Relevant source and data flows
Threat context and dependency findings

Expected outputs

Concrete hardening changes or findings
Validation of affected security behavior

Prerequisites

Authorized access to the application source and a permitted test environment.
A skill-based review does not establish compliance or replace a security assessment.

Installation

Agent

Run this command in your project after reviewing the instructions and access terms. Install complete upstream directories to keep referenced rules and scripts.

npx skills add https://github.com/addyosmani/agent-skills/tree/aeac41d4d005999432bb7312f7ff06383a91d59d/skills/security-and-hardening --skill security-and-hardening --agent claude-code

Project file: .claude/skills/security-and-hardening/SKILL.md

Read the setup guide

Selection brief

This brief helps you choose the skill. Read the complete upstream SKILL.md and companion files for its actual instructions.

# Addy Osmani application hardening (addy-osmani-security-hardening)
Addy Osmani’s security skill covers web application trust boundaries, authentication, authorization, data handling, dependency findings and external integrations.

## Use when
- Implement or review web features that handle untrusted data or user sessions.

## Required inputs
- Relevant source and data flows
- Threat context and dependency findings

## Prerequisites
- Authorized access to the application source and a permitted test environment.
- A skill-based review does not establish compliance or replace a security assessment.

## Expected outputs
- Concrete hardening changes or findings
- Validation of affected security behavior

Source: https://github.com/addyosmani/agent-skills/blob/aeac41d4d005999432bb7312f7ff06383a91d59d/skills/security-and-hardening/SKILL.md
Full SKILL.md: https://agenttaste.dev/skills/addy-osmani-security-hardening/SKILL.md

## Popularity evidence
- 108,660 GitHub repo stars — addyosmani/agent-skills; checked 2026-10-20. Source: https://github.com/addyosmani/agent-skills/stargazers
- 64,634 skill installs (all time) — addyosmani/agent-skills / security-and-hardening · skills.sh · all time; checked 2026-10-20. Source: https://skills.sh/addyosmani/agent-skills/security-and-hardening
Adoption counts are not user ratings or guarantees of quality.