playbook-webapp

A method and routing guide for testing web applications and HTTP APIs, which are web interfaces used by programs. It lays out the order from discovery and mapping to testing each vulnerability type, proving impact, and reporting.

In plain words
What is it for?
Use it to identify the technology stack, APIs, content, parameters, authentication paths, and client-side endpoints, then choose focused tests for issues such as SQL injection, server-side request forgery, or template injection.
Why use it?
It prevents random testing and points the tester to a more specific guide based on the web surface or behavior found.

Skill for Claude CodeCodex

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/s0ld13rr/pentestcode/webapp
Any agent
npx skills add s0ld13rr/pentestcode --skill webapp
Clone the repo
git clone --depth 1 https://github.com/s0ld13rr/pentestcode

Made for: Claude Code, Codex.

Per session 78 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 673 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00078 $0.00673
Opus 5 $0.00039 $0.00336
Sonnet 5 $0.00016 $0.00135
Haiku 4.5 $0.00008 $0.00067

Measured yesterday against content hash 3ae0659e1511, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

playbook-webapp scanned grade A with 0 findings 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.

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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/playbooks/webapp/SKILL.md · 33 lines

How it starts

The opening of the file, as written. The whole thing — 33 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Web App Pentest — methodology + skill router

This is the ORDER of operations and the map to the deep skills. Each vuln CLASS has a dedicated web-<class> skill with exact payloads + detect→exploit→PROVE — load the one matching the surface; don't test from this index.

1. Recon + active scan FIRST

Fingerprint stack+version (whatweb/httpx, headers), CMS (wpscan/etc.), APIs (/swagger, /graphql, /.well-known). Then a content-matched nuclei -u <t> pass BEFORE exhaustive dir-fuzz (framework-runtime RCEs don't appear as routes) → nuclei_parse. Version + a known CVE → fetch & vet a public PoC (shared exploitation methodology).

2. Map (hidden surface, AFTER the scan)

ffuf/gobuster (→ gobuster_parse), vhosts (ffuf -H Host:FUZZ), params (arjun), auth endpoints (login/register/reset/OAuth), API routes. Review client-side JS for endpoints/secrets.

3. Test by class → load the matching skill

Signal / surface Load
param → DB query, SQL error/differential web-sqli
input renders in a server template ({{7*7}}) web-ssti
server fetches a URL you control (webhook/proxy/import) web-ssrf
file param / download / ../ reflection web-lfi-traversal
file upload sink web-upload-rce
XML/SOAP/SAML/DOCX/SVG parsing web-xxe
serialized blob (rO0/O:/VIEWSTATE/pickle) web-deserialization
object IDs, roles, JWT, admin funcs web-auth-bypass-idor
known framework+version CVE shared exploitation methodology + searchsploit/nuclei
Also-check (no dedicated skill yet): XSS (dalfox, xss_detect), command injection (;id/$(id)), CSRF, CORS/security-headers, crypto/secrets-in-JS, business-logic/race conditions.

4. PROVE + Report

A finding is suspected until you reproduce concrete impact (dumped canary row / id / file bytes / cloud creds / cross-user data) — then add_vuln confirmed with the evidence. Never mark a host resolved/"safe" without a completed active scan. Report: reproduction steps + request/response evidence + CVSS + OWASP-WSTG mapping.

Read the full file on GitHub · 33 lines

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 · 33 lines · 78 tokens per session scan A 3ae0659e1511

Subscribe to this mod's changes

playbook-webapp is a skill published in the GitHub repository s0ld13rr/pentestcode (566 stars, last pushed 11d ago), licensed MIT. It adds 78 tokens to every session and 673 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.