Claude Code Guide is a reference collection for configuring and using Claude Code, Anthropic’s command-line coding agent. Developers use it to learn commands, skills, agents, MCP, automation, security, integrations, and troubleshooting. Its catalogue add-ons provide many of the documented skills and agents.
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.
npx skills add zebbern/claude-code-guide --skill broken-authenticationgit clone --depth 1 https://github.com/zebbern/claude-code-guideWrote 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.
[](https://agentmods.dev/skills/zebbern/claude-code-guide/broken-authentication)<a href="https://agentmods.dev/skills/zebbern/claude-code-guide/broken-authentication"><img src="https://agentmods.dev/badge/skills/zebbern/claude-code-guide/broken-authentication/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.
<a href="https://agentmods.dev/skills/zebbern/claude-code-guide/broken-authentication"><img src="https://agentmods.dev/badge/skills/zebbern/claude-code-guide/broken-authentication.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high YARA Match · line 110 YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
- medium Excessive Agency · line 284 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00067 | $0.03045 |
| Opus 5.5 | $0.00027 | $0.01218 |
| Sonnet 5.5 | $0.00013 | $0.00609 |
| Haiku 4.5 | $0.00007 | $0.00304 |
Grade A, and why
broken-authentication 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 1mo 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
response = requests.get("https://target.com/login") Copies of this mod
2 near-identical copies found in the catalogue:
- Broken Authentication Testing — 92% identical, 2 lines differ
- Broken Authentication Testing — 92% identical, 2 lines differ
How it starts
The opening of the file, as written. The whole thing — 477 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Broken Authentication Testing
Purpose
Identify and exploit authentication and session management vulnerabilities in web applications. Broken authentication consistently ranks in the OWASP Top 10 and can lead to account takeover, identity theft, and unauthorized access to sensitive systems. This skill covers testing methodologies for password policies, session handling, multi-factor authentication, and credential management.
Prerequisites
Required Knowledge
- HTTP protocol and session mechanisms
- Authentication types (SFA, 2FA, MFA)
- Cookie and token handling
- Common authentication frameworks
Required Tools
- Burp Suite Professional or Community
- Hydra or similar brute-force tools
- Custom wordlists for credential testing
- Browser developer tools
Required Access
- Target application URL
- Test account credentials
- Written authorization for testing
Outputs and Deliverables
- Authentication Assessment Report - Document all identified vulnerabilities
- Credential Testing Results - Brute-force and dictionary attack outcomes
- Session Security Analysis - Token randomness and timeout evaluation
- Remediation Recommendations - Security hardening guidance
Core Workflow
Phase 1: Authentication Mechanism Analysis
Understand the application's authentication architecture:
# Identify authentication type
- Password-based (forms, basic auth, digest)
- Token-based (JWT, OAuth, API keys)
- Certificate-based (mutual TLS)
- Multi-factor (SMS, TOTP, hardware tokens)
# Map authentication endpoints
/login, /signin, /authenticate
/register, /signup
/forgot-password, /reset-password
/logout, /signout
/api/auth/*, /oauth/*
Capture and analyze authentication requests:
POST /login HTTP/1.1
Host: target.com
Content-Type: application/x-www-form-urlencoded
username=test&password=test123
Phase 2: Password Policy Testing
Evaluate password requirements and enforcement:
# Test minimum length (a, ab, abcdefgh)
# Test complexity (password, password1, Password1!)
# Test common weak passwords (123456, password, qwerty, admin)
# Test username as password (admin/admin, test/test)
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.
- 1mo ago First seen · 477 lines · 67 tokens per session scan A 36289965b69c
broken-authentication is a skill published in the GitHub repository zebbern/claude-code-guide (4,669 stars, last pushed yesterday), licensed MIT. It adds 67 tokens to every session and 3,045 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-08-30.
Other skills, from other repositories
cdb-scan
Map this codebase into project memory — a code graph of every symbol and how they connect, plus a written profile of stack, layout, conventions and workflows. Re-run any time to refresh both in place. Use when memory is newly installed on an existing project, or when the project has changed enough that the stored map…
handoff
Write a short handoff note for the next chat or a teammate, with what is done, what is open, what comes next and what was rejected and why. Saves it to project memory so the next chat sees it at the start, and prints it so it can be pasted into a message or a pull request. Use when the user ends a piece of work…
mckinsey-consultant
A consulting style method for breaking business questions into structured analyses and producing research reports or presentations.
catchup
Answer "where did I stop?" for this project. Gives three short groups, done, open and next, taken from the last chat, the recorded to-dos, the last handoff note and git. Use when the user comes back to a project, starts a new chat, or asks where they left off. It writes nothing.
security-claude
Skill "security-claude" from rahozosman/security-claude, covering security architecture & threat modeling intelligence, how this skill is organized (progressive disclosure), 1. pick a mode, 2. core method (applies to every mode) and 3. doing a focused review.
run-tests
Run the pytest suite, report pass/fail counts and coverage, and identify untested code. Use when the user asks to run tests, check test coverage, or verify that changes didn't break anything.