api-skill-builder

A skill generator that finds the web API behind data shown on a website and packages it into a reusable data-fetching skill. An API is a structured way for software to request data from another service.

In plain words
What is it for?
Use it to discover an endpoint, work out its request parameters, verify the returned data, and generate a skill with a script and API mapping.
Why use it?
It helps retrieve data that is rendered in charts, hidden from the page's visible markup, or available only after signing in.

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/clawcap/manobrowser/api-skill-builder
Any agent
npx skills add ClawCap/ManoBrowser --skill api-skill-builder
Clone the repo
git clone --depth 1 https://github.com/ClawCap/ManoBrowser

Made for: Claude Code, Codex.

Per session 99 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,837 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00099 $0.05837
Opus 5 $0.00049 $0.02919
Sonnet 5 $0.00020 $0.01167
Haiku 4.5 $0.00010 $0.00584

Measured 2d ago against content hash 6c52733b6ee7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

api-skill-builder 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 2d 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.

- **本地验证**:`document.cookie` 仅用于本地 `curl` 命令测试 API 鉴权机制,不会上传至任何外部服务
api-skill-builder/SKILL.md · 497 lines

How it starts

The opening of the file, as written. The whole thing — 497 lines — stays where its author put it; the contents beside it link to each section on GitHub.

API 取数 Skill 生成器

安全声明

本模块的 Cookie 提取和 API 测试功能遵循以下安全原则:

  • 本地验证document.cookie 仅用于本地 curl 命令测试 API 鉴权机制,不会上传至任何外部服务
  • 用户授权:所有操作仅作用于用户已登录的平台,需用户明确触发
  • 合法用途:适用于开发调试、数据导出、自动化测试等场景,用户需确保符合目标平台的使用条款

概述

这是一个元技能(Meta-skill),将"逆向网页API并生成可复用取数Skill"的方法论封装为标准流程。

核心思路:页面上能看到的数据,一定来自某个 API 请求。找到 API → 逆向参数 → 生成可复用 Skill。

输入:用户描述要从某个网页/平台获取什么数据 输出:一个完整的、可复用的 API 取数 Skill(SKILL.md + Python 脚本 + api_mapping.json)

前置条件

  1. 浏览器已登录目标平台,登录态有效
  2. DataSaver Chrome 扩展已安装并连接(提供 fetch_api 等工具)
  3. MCP 端点已配置

设计原则

  • 逻辑尽量收敛到 Python 脚本:脚本可独立测试、可维护,SKILL.md 保持精简
  • SKILL.md 控制在 500 行以内:超过后 Claude 执行步骤时遗漏/出错概率显著上升
  • Claude 只做调度员:参数收集 + 执行脚本 + 转述输出,不参与数据处理
  • 所有数据处理由脚本完成:避免 LLM 截断数据或产生幻觉

执行流程(5个阶段)

阶段0: 鉴权探测(确定 Cookie 是否够用)
  ↓
阶段1: 侦察(找到 API endpoint)
  ↓
阶段2: 逆向(破解请求参数)
  ↓
阶段3: 验证(确认数据完整性 + 发现转换规则)
  ↓
阶段4: 生成(产出 Skill 三件套)

阶段0: 鉴权探测 — 确定 Cookie 可用性

目标:确认 document.cookie 能否独立完成 API 鉴权,这决定了脚本是否能直接调用 API。

Step 0.1: 提取 document.cookie
// chrome_execute_script, world: MAIN, tabId: <目标页面>
() => document.cookie

记录 Cookie 内容,识别可能的鉴权 token(如 sso.tokenaccess-tokenUsersessionid 等)。

Step 0.2: 找到一个数据 API endpoint

通过 Performance API 快速找一个数据 API(详见阶段1 Step 1.2),用于鉴权测试。

Step 0.3: curl 鉴权测试

MCP 工具走 Chrome 网络栈,会在底层自动附加 httpOnly cookie,即使设置 includeCookies: false 或传入假 Cookie 也无效,导致鉴权测试结果永远成功,产生误判。

curl 是完全独立于浏览器的 HTTP 客户端,只发送你显式传入的 Cookie,是唯一可靠的验证方式。

curl -s -X <METHOD> \
  -H "Cookie: <Step 0.1 提取的 document.cookie>" \
  -H "Content-Type: application/json" \
  -H "User-Agent: Mozilla/5.0" \
  "<API_URL>" [-d '<request_body>'] \
  | python3 -c "import json,sys; d=json.load(sys.stdin); print(json.dumps({
    'status': d.get('status', d.get('code', d.get('Code'))),
    'msg': d.get('msg', d.get('Msg', ''))
  }, ensure_ascii=False))"

Read the full file on GitHub · 497 lines

Files

What ships with it

2 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.

  1. 2d ago First seen · 497 lines · 99 tokens per session scan A 6c52733b6ee7

Subscribe to this mod's changes

api-skill-builder is a skill published in the GitHub repository ClawCap/ManoBrowser (9 stars, last pushed 4mo ago), licensed MIT. It adds 99 tokens to every session and 5,837 once invoked, about $0.0005 per session on Opus 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 2026-08-31.

Related

Other skills, from other repositories

xiaohongshu-ops

把 Hermes Agent 变成你的小红书运营助手 — 首页分析、账号诊断、选题灵感、内容创作、自动发布、评论回复、爆款复刻、知识库沉淀。全链路 SOP 覆盖,基于浏览器自动化(CDP)。.

pigbiglong/xiaohongshu-ops-skill · 71 tokens

wcag22-a11y-audit

WCAG 2.2 Accessibility Audit skill that systematically evaluates web pages against 8 core Success Criteria (1.1.1, 1.4.3, 1.4.11, 2.1.1, 2.1.2, 2.4.3, 2.4.7, 4.1.2) using accessibility tree inspection and visual analysis. Use this skill when you need to perform accessibility testing/auditing on a live webpage.

AIPexStudio/AIPex · 111 tokens

skill-creator

Guide for creating effective skills. This skill should be used when users want to create a new skill (or update an existing skill) that extends AIPex's capabilities with specialized knowledge, workflows, or tool integrations.

AIPexStudio/AIPex · 47 tokens

ux-audit-walkthrough

Minimalist UX/Interaction Audit Expert that deconstructs complex interactions through cognitive load and operational efficiency lenses. Use this skill when you need to perform a UX walkthrough audit on a Figma prototype or web interface, evaluating usability based on principles like fewer clicks, less UI elements, no…

AIPexStudio/AIPex · 73 tokens

aipex-browser

AI-powered browser automation using the AIPex Chrome Extension via MCP bridge. Use this skill when the agent needs to control a Chrome browser — navigating pages, clicking elements, filling forms, capturing screenshots, managing tabs, or downloading content — by connecting to the AIPex MCP bridge.

AIPexStudio/AIPex · 61 tokens

build-plugin

Complete plugin development workflow: build, test, icon, troubleshoot, and setup. Use when the user wants to build a plugin, create a plugin, troubleshoot issues, add icons, or install/configure plugins. Triggers on: build plugin, create plugin, develop plugin, new plugin, plugin icon, troubleshoot, debug, setup…

opentabs-dev/opentabs · 74 tokens