# Security

> Guides AI agents to write secure Fastify/Node.js code — input validation, authentication, injection prevention, and safe error handling.

- **Type:** Skill
- **Install:** `agentstack add skill-jesus-seijas-sp-claude-node-setup-security`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [jesus-seijas-sp](https://agentstack.voostack.com/s/jesus-seijas-sp)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [jesus-seijas-sp](https://github.com/jesus-seijas-sp)
- **Source:** https://github.com/jesus-seijas-sp/claude-node-setup/tree/main/.claude/skills/security

## Install

```sh
agentstack add skill-jesus-seijas-sp-claude-node-setup-security
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Security Skill

Use this skill when writing any code that handles user input, authentication, authorization, or external data. Security rules apply to all features, not just auth-related ones.

## When to Use

- Writing or reviewing route handlers that accept user input
- Implementing authentication or authorization logic
- Querying databases or calling external services with user-supplied data
- Handling file uploads or user-provided file paths
- Returning error messages to clients
- Setting HTTP headers or cookies

## Rules

1. [rules/input-validation.md](rules/input-validation.md) — Validate and sanitize all input at the boundary using Fastify JSON Schema.
2. [rules/injection.md](rules/injection.md) — Prevent SQL, NoSQL, command, and path injection.
3. [rules/auth.md](rules/auth.md) — Authentication patterns: JWT verification, session hygiene, and authorization checks.
4. [rules/error-handling.md](rules/error-handling.md) — Safe error responses that never leak internals.
5. [rules/headers.md](rules/headers.md) — Secure HTTP headers and cookie attributes.

## Quick Reference

- Always define a schema — Fastify rejects non-conforming input automatically
- Never expose internal errors to the client
- Authorization — always check ownership, not just authentication

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [jesus-seijas-sp](https://github.com/jesus-seijas-sp)
- **Source:** [jesus-seijas-sp/claude-node-setup](https://github.com/jesus-seijas-sp/claude-node-setup)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-jesus-seijas-sp-claude-node-setup-security
- Seller: https://agentstack.voostack.com/s/jesus-seijas-sp
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.