web-security-baseline

web-security-baseline is a skill for Claude Code, Codex from Xipher-Labs/walter-os. It costs 142 tokens per session (2,921 once invoked), scanned B, original, AGPL-3.0.

A baseline security review for web application code based on the OWASP Top 10, a list of common web security risks.

In plain words
What is it for?
Use it when reviewing changes to web handlers, login flows, cookies, file uploads, redirects, or other application security code.
Why use it?
It helps catch problems in authentication, sessions, browser protections, data handling, uploads, redirects, and related HTTP code.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

Good fit Use it when reviewing changes to web handlers, login flows, cookies, file uploads, redirects, or other application security code.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/xipher-labs/walter-os/web-security-baseline
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.

Any agent
npx skills add Xipher-Labs/walter-os --skill web-security-baseline
Clone the repo
git clone --depth 1 https://github.com/Xipher-Labs/walter-os

Made for: Claude Code, Codex.

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-baseline

README.md
[![agentmods](https://agentmods.dev/badge/skills/xipher-labs/walter-os/web-security-baseline/github.svg)](https://agentmods.dev/skills/xipher-labs/walter-os/web-security-baseline)
Your own site
<a href="https://agentmods.dev/skills/xipher-labs/walter-os/web-security-baseline"><img src="https://agentmods.dev/badge/skills/xipher-labs/walter-os/web-security-baseline/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for web-security-baseline

Your own site · 80×15
<a href="https://agentmods.dev/skills/xipher-labs/walter-os/web-security-baseline"><img src="https://agentmods.dev/badge/skills/xipher-labs/walter-os/web-security-baseline.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 142 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,921 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown 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 $0.00142 $0.02921
Opus 5 $0.00071 $0.01460
Sonnet 5 $0.00028 $0.00584
Haiku 4.5 $0.00014 $0.00292

Measured 7d ago against content hash 6b78700a74c8, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade B, and why

web-security-baseline scanned grade B 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 7d ago.

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.

Cloud metadata endpointmediumServer-side request forgery

One request to 169.254.169.254 can return temporary IAM credentials.

- **Block metadata services**: 169.254.169.254 (AWS/GCP/Azure metadata),

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

skills/web-security-baseline/SKILL.md · 267 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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. 7d ago First seen · 267 lines · 142 tokens per session scan B 6b78700a74c8

Subscribe to this mod's changes

web-security-baseline is a skill published in the GitHub repository Xipher-Labs/walter-os (6 stars, last pushed 7d ago), licensed AGPL-3.0. It adds 142 tokens to every session and 2,921 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it B with 1 finding (cloud metadata endpoint). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.