web-security

web-security is a skill for Claude Code from Everyone-Needs-A-Copilot/claude-copilot. It costs 111 tokens per session (2,006 once invoked), scanned A, original, MIT.

A web application security review guide based on the OWASP Top 10, a widely used list of common web security risks. It covers issues such as injection, weak access controls, unsafe authentication, cross-site scripting, and server-side request forgery.

In plain words
What is it for?
Reviewing web applications and APIs, mapping findings to OWASP categories, and checking for missing security coverage.
Why use it?
It helps find security weaknesses before they reach production and prevents a review from overlooking whole classes of risks. A coverage check also identifies OWASP areas with no findings.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: reads .claude/ paths.

Part of the claude-copilot plugin — 72 skills, 17 commands, 17 agents, 4 hooks shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/everyone-needs-a-copilot/claude-copilot/web-security
Any agent
npx skills add Everyone-Needs-A-Copilot/claude-copilot --skill web-security
Clone the repo
git clone --depth 1 https://github.com/Everyone-Needs-A-Copilot/claude-copilot

Made for: Claude Code.

Or install claude-copilot, the plugin that ships this one along with the rest of its 72 skills, 17 commands, 17 agents, 4 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for web-security

README.md
[![agentmods](https://agentmods.dev/badge/skills/everyone-needs-a-copilot/claude-copilot/web-security.svg)](https://agentmods.dev/skills/everyone-needs-a-copilot/claude-copilot/web-security)
Your own site
<a href="https://agentmods.dev/skills/everyone-needs-a-copilot/claude-copilot/web-security"><img src="https://agentmods.dev/badge/skills/everyone-needs-a-copilot/claude-copilot/web-security.svg" alt="Measured on agentmods" height="20"></a>
Per session 111 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,006 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00111 $0.02006
Opus 5 $0.00056 $0.01003
Sonnet 5 $0.00022 $0.00401
Haiku 4.5 $0.00011 $0.00201

Measured yesterday against content hash 6e39affec1c7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

web-security scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/owasp_score.py, scripts/test_owasp_score.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

const response = await fetch(req.body.url);
.claude/skills/security/web-security/SKILL.md · 212 lines

How it starts

The opening of the file, as written. The whole thing — 212 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Web Security

Comprehensive web application security patterns covering OWASP Top 10 (2021). Apply before code review, not after.

OWASP analysis is prose judgment — the model reasons about attack vectors, code patterns, and mitigations. OWASP coverage is deterministic — the script validates that every finding maps to a real OWASP category and reports which of the 10 categories have zero findings (the blind spots).

Never report a "clean" security review without running the coverage checker.

OWASP Top 10 (2021) — Quick Reference

Code Category Core Risk
A01 Broken Access Control Unauthorized access, IDOR, privilege escalation
A02 Cryptographic Failures Plaintext storage, weak algorithms, missing TLS
A03 Injection SQL, NoSQL, OS, LDAP injection; XSS
A04 Insecure Design Missing threat model, no security requirements
A05 Security Misconfiguration Default creds, verbose errors, open CORS
A06 Vulnerable and Outdated Components CVE-carrying dependencies
A07 Identification and Authentication Failures Weak passwords, no MFA, session issues
A08 Software and Data Integrity Failures Unsigned updates, unsafe deserialization
A09 Security Logging and Monitoring Failures Undetected breaches, missing audit logs
A10 Server-Side Request Forgery (SSRF) Internal service access via user-controlled URLs

Invocation — OWASP Coverage Scorer (L3 Script)

After identifying findings, assemble them as a JSON array and run the scorer. Consume its output only — the script source never enters context.

Format each finding:

[
  {
    "title": "Admin endpoint lacks authentication check",
    "owasp": "A01",
    "severity": "Critical",
    "status": "open"
  }
]

OWASP field: Use short codes A01A10, or full OWASP 2021 category names (e.g. "Injection"), or common shorthands ("SSRF", "IDOR", "sqli", "authentication").

severity field (optional): Critical | High | Medium | Low

Read the full file on GitHub · 212 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 212 lines · 111 tokens per session scan A 6e39affec1c7

Subscribe to this mod's changes

web-security is a skill published in the GitHub repository Everyone-Needs-A-Copilot/claude-copilot (13 stars, last pushed yesterday), licensed MIT. It adds 111 tokens to every session and 2,006 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-04.

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