# Security And Hardening

> Apply baseline frontend security checks when handling untrusted data, auth-sensitive UI, forms, or external content.

- Skill: `counterpointconsulting/security-and-hardening-3` (Agent Skill)
- Install (CLI): `npx skillmds@latest add counterpointconsulting/security-and-hardening-3`
- Raw SKILL.md: https://api.skillmd.com/api/skills/counterpointconsulting/security-and-hardening-3/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Web & Frontend
- Author: CounterpointConsulting (https://skillmd.com/u/counterpointconsulting)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/counterpointconsulting/security-and-hardening-3

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# Security and Hardening (TypeScript React)

## Overview
Reduce client-side security risk by validating rendering and interaction boundaries for untrusted or sensitive data flows.

## When to Use
- Rendering user/external content
- Auth/session-sensitive UI
- Form input handling and submission flows
- New API response handling paths in UI

## When NOT to Use
- Changes with no user data or security-sensitive behavior impact

## Inputs
- UI diff and data flow context
- Auth/session behavior expectations
- Rendering and form handling pathways

## Process
1. Check untrusted content rendering safety.
2. Verify form validation and error flows.
3. Ensure auth-sensitive UI doesn’t expose restricted data.
4. Confirm no secrets/tokens are hard-coded or logged.

## Verification Checklist
- [ ] Untrusted data is rendered safely
- [ ] Validation/error handling is explicit
- [ ] Restricted UI/data paths respect auth boundaries
- [ ] No sensitive values leak through logs/code

## Failure Modes to Avoid
- Unsafe rendering assumptions
- Treating UI-only checks as full security boundary
- Missing negative-path validation checks

## Output Requirements
- Use `summarize` for final output.
- Include security checks performed and residual risk.