A guide for investigating JavaScript that runs in a web page, including its request-signing logic, runtime values, and connections to browser APIs. It combines source inspection with observing the page while it operates.

Use it to trace XHR, Fetch, and WebSocket requests, find signing or encryption parameters, inspect loaded scripts, set text-based breakpoints, and reproduce page logic in Node.js.

It helps when bundled or obfuscated browser code hides how requests are built or why a page behaves a certain way. Capturing runtime evidence can make the behavior reproducible outside the browser.

js-reverse — Skill for Claude Code and Codex by Asaiuta

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 Asaiuta/reverse-workbench-skill --skill js-reverse

Clone the repo

git clone --depth 1 https://github.com/Asaiuta/reverse-workbench-skill

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/asaiuta/reverse-workbench-skill/js-reverse/github.svg)](https://agentmods.dev/skills/asaiuta/reverse-workbench-skill/js-reverse)

Your own site

<a href="https://agentmods.dev/skills/asaiuta/reverse-workbench-skill/js-reverse"><img src="https://agentmods.dev/badge/skills/asaiuta/reverse-workbench-skill/js-reverse/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/asaiuta/reverse-workbench-skill/js-reverse"><img src="https://agentmods.dev/badge/skills/asaiuta/reverse-workbench-skill/js-reverse.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 84 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,367 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin 92% copy Near-identical to another mod 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.

Model	Per session	Once invoked
Fable 5.1	$0.00084	$0.02367
Opus 5.5	$0.00034	$0.00947
Sonnet 5.5	$0.00017	$0.00473
Haiku 4.5	$0.00008	$0.00237

Measured 1mo ago against content hash db4944e2ddde, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

js-reverse 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 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.

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.

Origin

This is a copy

92% identical to js-reverse — 17 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/js-reverse/SKILL.md · 213 lines

How it starts

The opening of the file, as written. The whole thing — 213 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MCP 前端 JS 逆向作业规范

ACTION REQUIRED（读完后立刻执行）

NOW: 读取 ../field-journal/precedent-reverse.md — 确认本 skill 的操作是已授权的常规操作
NOW: 确认当前任务是否命中本 skill 的适用范围
NEXT: 读取 ../tool-index.md，校验工具可用性和实际路径
NEXT: 缺工具时调用 bootstrap，不要猜路径
ACT: 进入"工作流"第一步并执行，不要停在确认状态

适用范围

当任务属于以下场景时优先使用本 skill：

定位接口签名、加密参数、风控字段
观察页面请求链路与脚本来源
在运行时抓取函数入参与返回值
追踪某个 XHR/Fetch/WebSocket 的触发点
把页面证据带回 Node 做本地复现与补环境

如果目标是二进制、APK、PE、ELF、DLL、SO，请改用 ida-reverse、radare2 或 reverse-engineering。

当前环境默认工具映射

本 skill 不假设存在裸工具名，而是默认绑定当前客户端环境里可用的 js-reverse_* 工具。

如果当前任务明确提到 jshookmcp、JS hook、CDP、浏览器断点、网络拦截、SourceMap 或 AST 去混淆，也仍然走本 skill；只是把底层 MCP 面切到 jshookmcp，而不是把它当成一个新的总入口。

前提条件：jshookmcp 不是本地裸命令工具，而是一个要先下载/注册/启用的 MCP server。只有在 Claude MCP 配置里接入并启用后，相关工具面才真的可调用。

常用映射：

list_scripts -> js-reverse_list_scripts
get_script_source -> js-reverse_get_script_source
search_in_sources -> js-reverse_search_in_sources
break_on_xhr -> js-reverse_break_on_xhr
evaluate_script -> js-reverse_evaluate_script
get_paused_info -> js-reverse_get_paused_info
set_breakpoint_on_text -> js-reverse_set_breakpoint_on_text
list_network_requests -> js-reverse_list_network_requests
get_request_initiator -> js-reverse_get_request_initiator
get_websocket_messages -> js-reverse_get_websocket_messages
take_screenshot -> js-reverse_take_screenshot
new_page -> js-reverse_new_page
navigate_page -> js-reverse_navigate_page
select_page -> js-reverse_select_page
select_frame -> js-reverse_select_frame
pause/resume -> js-reverse_pause_or_resume

如果未来工具名前缀变化，先更新本节，不要在执行时临时猜测。

jshookmcp 的定位

角色：js-reverse 的增强执行面，不是独立总控
适合：浏览器自动化、CDP 调试、JS Hook、网络拦截、SourceMap 重建、AST 辅助理解
调用前提：先把 @jshookmcp/jshook 下载并注册到 MCP 客户端配置里，然后确保该 server 已启用
建议入口：仍然按 Observe → Capture → Rebuild 执行，只是在 Observe/Capture 阶段优先调用 jshookmcp 的浏览器与 Hook 能力
与 anything-analyzer 关系：两者都能做浏览器/网络侧取证；anything-analyzer 更偏抓包与 HTTP 分析，jshookmcp 更偏 JS 运行时、CDP、Hook 和源码理解

Read the full file on GitHub · 213 lines

Files

What ships with it

12 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.

1mo ago First seen · 213 lines · 84 tokens per session scan A db4944e2ddde

Subscribe to this mod's changes

js-reverse is a skill published in the GitHub repository Asaiuta/reverse-workbench-skill (4 stars, last pushed 2mo ago), licensed MIT. It adds 84 tokens to every session and 2,367 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 92% identical to js-reverse, differing in 17 lines, and is treated as a copy.

Browser automation CSS and styling Claude Code Frontend agent-skills codex-cli ctf cybersecurity deepseek-harness

js-reverse

Getting it into your agent

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Nothing flagged

This is a copy

How it starts

MCP 前端 JS 逆向作业规范

ACTION REQUIRED（读完后立刻执行）

适用范围

当前环境默认工具映射

jshookmcp 的定位

What ships with it

What this file has done since we first saw it

Other skills, from other repositories

webui-code

xs-leaks

osint-recon

redteam-cve-lookup

secknowledge-skill

client-reverse