Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/forefy/.contextnpx agentmods add skills/forefy/.context/webapp-probeWrote 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/forefy/.context/webapp-probe)<a href="https://agentmods.dev/skills/forefy/.context/webapp-probe"><img src="https://agentmods.dev/badge/skills/forefy/.context/webapp-probe/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/forefy/.context/webapp-probe"><img src="https://agentmods.dev/badge/skills/forefy/.context/webapp-probe.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00043 | $0.06564 |
| Opus 5.5 | $0.00017 | $0.02626 |
| Sonnet 5.5 | $0.00009 | $0.01313 |
| Haiku 4.5 | $0.00004 | $0.00656 |
Grade C, and why
webapp-probe scanned grade C with 2 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Downloads and executes remote codehighSupply chain
curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.
curl -s "https://TARGET/${s}.map" | python3 -c 'import sys,json; Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
import sys,urllib.parse as u How it starts
The opening of the file, as written. The whole thing — 304 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Contents
- Scope & authorization (blast-radius labels)
- Passive analysis of captured traffic:
- Missing or weak security headers
- Insecure session cookies
- Hardcoded secrets & API tokens in bodies
- Improper error handling (stack traces, DB errors, debug pages)
- Outdated / dev-mode technology fingerprints
- RCE-prone parameters in captured requests
- Active probing of the live target: 7. Disclosure-path brute (.git/config/logs, CVE paths) 8. Outdated / vulnerable software port probe 9. Wayback forgotten-endpoint mining + re-probe 10. Dependency confusion (sourcemaps -> npm)
- Runnable snippets
- Output
- Reference files:
references/secret-regexes.md,references/error-signatures.md,references/directory-signatures.md
Scope & authorization
Only run against a web application the user owns or is contractually engaged to test. This skill has two halves, each labelled by blast radius:
- Passive (classes 1-6) - inspects responses and requests you already captured (proxy history, an authenticated crawl, a saved sitemap, files on disk). Sends no new HTTP requests, mutates nothing, and is safe against a frozen capture.
- Active (checks 7-10) - sends live requests to the target and, for Wayback (9) and dependency confirmation (10), to third-party services (the Internet Archive, the npm registry). Check 8 is aggressive (multi-port sweep). Run these only in scope, and prefer a low-traffic window.
Take inputs as whatever you already hold: captured responses/requests for the passive half, and the target's domains / domain:port pairs for the active half. Report a finding exactly where each section says "Report a finding when...".
Passive analysis of captured traffic
Each class is one pass over the capture; each yields per-target findings.
0. Extensive attack surface flushout and coverage
Work through the given scope of the target, and work to maximize all the attack surface expansion via all techniques that comes to mind.
What ships with it
3 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.
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 Changed · +10 lines 8d16b6310914
- 1mo ago First seen · 294 lines · 43 tokens per session scan C 193d71edbe1f
webapp-probe is a skill published in the GitHub repository forefy/.context (153 stars, last pushed yesterday), licensed MIT. It adds 43 tokens to every session and 6,564 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it C with 2 findings (downloads and executes remote code, 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
eresus-manual-security-audit
Elite manual security code review skill for deep, adversarial vulnerability hunting and exploit-chain discovery. Trigger when the user asks to: "do a deep security audit", "manual code review", "find exploit chains", "hunt for logic bugs", "red-team this codebase", "do an offensive security review", "review this like…
eresus-php-audit
Deep PHP-specific security audit skill covering injection, deserialization, file operations, auth bypass, POP chain discovery, and CMS-specific patterns. Trigger when auditing PHP code: "audit this PHP app", "find PHP security issues", "check Laravel/WordPress for vulnerabilities", "PHP SAST review", "check for PHP…
eresus-python-audit
Deep Python-specific security audit skill with 50+ vulnerability class coverage across 7 categories. Trigger when auditing Python code: "audit this Python app", "find Python security issues", "check Flask/Django for vulnerabilities", "Python SAST review", "check for pickle vulnerabilities", "review this FastAPI code".…
eresus-sast-scanner
General-purpose Static Application Security Testing (SAST) skill for code vulnerability analysis. Trigger when the user asks to: "analyze code for vulnerabilities", "review code security", "find security bugs", "do a SAST scan", "check for [vulnerability type] in code", "audit source code", or requests a security code…
eresus-remediator
Security remediation skill for fixing confirmed or likely SAST findings in source code. Trigger when the user asks to: "fix a vulnerability", "patch this security bug", "remediate SAST findings", "harden this endpoint", "make this auth flow safe", or wants code changes that remove a confirmed security issue while…
eresus-variant-analysis
GHSA/CVE variant analysis workflow for finding similar vulnerability patterns across a codebase. Trigger when the user asks to: "find variants of this CVE", "GHSA variant analysis", "find similar bugs", "hunt for the same pattern", "are there other places with this vulnerability?", or when a known vulnerability is…