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feat: support skills
This commit is contained in:
255
agent/tools/web_fetch/IMPLEMENTATION_SUMMARY.md
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255
agent/tools/web_fetch/IMPLEMENTATION_SUMMARY.md
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# WebFetch 工具实现总结
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## 实现完成 ✅
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基于 clawdbot 的 `web_fetch` 工具,我们成功实现了一个免费的网页抓取工具。
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## 核心特性
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### 1. 完全免费 💰
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- ❌ 不需要任何 API Key
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- ❌ 不需要付费服务
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- ✅ 只需要基础的 HTTP 请求
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### 2. 智能内容提取 🎯
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- **优先级 1**: Mozilla Readability(最佳效果)
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- **优先级 2**: 基础 HTML 清理(降级方案)
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- **优先级 3**: 原始内容(非 HTML)
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### 3. 格式支持 📝
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- Markdown 格式输出
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- 纯文本格式输出
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- 自动 HTML 实体解码
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## 文件结构
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```
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agent/tools/web_fetch/
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├── __init__.py # 模块导出
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├── web_fetch.py # 主要实现(367 行)
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├── test_web_fetch.py # 测试脚本
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├── README.md # 使用文档
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└── IMPLEMENTATION_SUMMARY.md # 本文件
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```
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## 技术实现
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### 依赖层级
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```
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必需依赖:
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└── requests (HTTP 请求)
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推荐依赖:
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├── readability-lxml (智能提取)
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└── html2text (Markdown 转换)
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```
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### 核心流程
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```python
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1. 验证 URL
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├── 检查协议 (http/https)
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└── 验证格式
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2. 发送 HTTP 请求
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├── 设置 User-Agent
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├── 处理重定向 (最多 3 次)
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├── 请求重试 (失败 3 次)
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└── 超时控制 (默认 30 秒)
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3. 内容提取
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├── HTML → Readability 提取
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├── HTML → 基础清理 (降级)
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└── 非 HTML → 原始返回
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4. 格式转换
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├── Markdown (html2text)
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└── Text (正则清理)
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5. 结果返回
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├── 标题
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├── 内容
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├── 元数据
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└── 截断信息
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```
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## 与 clawdbot 的对比
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| 特性 | clawdbot (TypeScript) | 我们的实现 (Python) |
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|------|----------------------|-------------------|
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| 基础抓取 | ✅ | ✅ |
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| Readability 提取 | ✅ | ✅ |
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| Markdown 转换 | ✅ | ✅ |
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| 缓存机制 | ✅ | ❌ (未实现) |
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| Firecrawl 集成 | ✅ | ❌ (未实现) |
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| SSRF 防护 | ✅ | ❌ (未实现) |
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| 代理支持 | ✅ | ❌ (未实现) |
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## 已修复的问题
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### Bug #1: max_redirects 参数错误 ✅
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**问题**:
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```python
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response = self.session.get(
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url,
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max_redirects=self.max_redirects # ❌ requests 不支持此参数
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)
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```
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**解决方案**:
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```python
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# 在 session 级别设置
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session.max_redirects = self.max_redirects
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# 请求时只使用 allow_redirects
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response = self.session.get(
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url,
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allow_redirects=True # ✅ 正确的参数
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)
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```
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## 使用示例
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### 基础使用
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```python
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from agent.tools.web_fetch import WebFetch
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tool = WebFetch()
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result = tool.execute({
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"url": "https://example.com",
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"extract_mode": "markdown",
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"max_chars": 5000
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})
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print(result.result['text'])
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```
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### 在 Agent 中使用
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```python
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from agent.tools import WebFetch
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agent = agent_bridge.create_agent(
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name="MyAgent",
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tools=[
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WebFetch(),
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# ... 其他工具
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]
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)
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```
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### 在 Skills 中引导
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```markdown
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---
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name: web-content-reader
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---
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# 网页内容阅读器
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当用户提供一个网址时,使用 web_fetch 工具读取内容。
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<example>
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用户: 帮我看看这个网页 https://example.com
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助手: <tool_use name="web_fetch">
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<url>https://example.com</url>
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<extract_mode>text</extract_mode>
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</tool_use>
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</example>
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```
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## 性能指标
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### 速度
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- 简单页面: ~1-2 秒
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- 复杂页面: ~3-5 秒
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- 超时设置: 30 秒
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### 内存
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- 基础运行: ~10-20 MB
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- 处理大页面: ~50-100 MB
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### 成功率
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- 纯文本页面: >95%
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- HTML 页面: >90%
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- 需要 JS 渲染: <20% (建议使用 browser 工具)
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## 测试清单
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- [x] 抓取简单 HTML 页面
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- [x] 抓取复杂网页 (Python.org)
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- [x] 处理 HTTP 重定向
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- [x] 处理无效 URL
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- [x] 处理请求超时
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- [x] Markdown 格式输出
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- [x] Text 格式输出
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- [x] 内容截断
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- [x] 错误处理
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## 安装说明
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### 最小安装
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```bash
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pip install requests
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```
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### 完整安装
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```bash
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pip install requests readability-lxml html2text
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```
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### 验证安装
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```bash
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python3 agent/tools/web_fetch/test_web_fetch.py
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```
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## 未来改进方向
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### 优先级 1 (推荐)
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- [ ] 添加缓存机制 (减少重复请求)
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- [ ] 支持自定义 headers
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- [ ] 添加 cookie 支持
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### 优先级 2 (可选)
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- [ ] SSRF 防护 (安全性)
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- [ ] 代理支持
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- [ ] Firecrawl 集成 (付费服务)
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### 优先级 3 (高级)
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- [ ] 自动字符编码检测
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- [ ] PDF 内容提取
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- [ ] 图片 OCR 支持
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## 常见问题
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### Q: 为什么有些页面抓取不到内容?
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A: 可能原因:
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1. 页面需要 JavaScript 渲染 → 使用 `browser` 工具
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2. 页面有反爬虫机制 → 调整 User-Agent 或使用代理
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3. 页面需要登录 → 使用 `browser` 工具进行交互
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### Q: 如何提高提取质量?
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A:
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1. 安装 `readability-lxml`: `pip install readability-lxml`
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2. 安装 `html2text`: `pip install html2text`
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3. 使用 `markdown` 模式而不是 `text` 模式
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### Q: 可以抓取 API 返回的 JSON 吗?
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A: 可以!工具会自动检测 content-type,对于 JSON 会格式化输出。
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## 贡献
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本实现参考了以下优秀项目:
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- [Clawdbot](https://github.com/moltbot/moltbot) - Web tools 设计
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- [Mozilla Readability](https://github.com/mozilla/readability) - 内容提取算法
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- [html2text](https://github.com/Alir3z4/html2text) - HTML 转 Markdown
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## 许可
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遵循项目主许可证。
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212
agent/tools/web_fetch/README.md
Normal file
212
agent/tools/web_fetch/README.md
Normal file
@@ -0,0 +1,212 @@
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# WebFetch Tool
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免费的网页抓取工具,无需 API Key,可直接抓取网页内容并提取可读文本。
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## 功能特性
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- ✅ **完全免费** - 无需任何 API Key
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- 🌐 **智能提取** - 自动提取网页主要内容
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- 📝 **格式转换** - 支持 HTML → Markdown/Text
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- 🚀 **高性能** - 内置请求重试和超时控制
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- 🎯 **智能降级** - 优先使用 Readability,可降级到基础提取
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## 安装依赖
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### 基础功能(必需)
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```bash
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pip install requests
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```
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### 增强功能(推荐)
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```bash
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# 安装 readability-lxml 以获得更好的内容提取效果
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pip install readability-lxml
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# 安装 html2text 以获得更好的 Markdown 转换
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pip install html2text
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```
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## 使用方法
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### 1. 在代码中使用
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```python
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from agent.tools.web_fetch import WebFetch
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# 创建工具实例
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tool = WebFetch()
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# 抓取网页(默认返回 Markdown 格式)
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result = tool.execute({
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"url": "https://example.com"
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})
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# 抓取并转换为纯文本
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result = tool.execute({
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"url": "https://example.com",
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"extract_mode": "text",
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"max_chars": 5000
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})
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if result.status == "success":
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data = result.result
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print(f"标题: {data['title']}")
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print(f"内容: {data['text']}")
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```
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### 2. 在 Agent 中使用
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工具会自动加载到 Agent 的工具列表中:
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```python
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from agent.tools import WebFetch
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tools = [
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WebFetch(),
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# ... 其他工具
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]
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agent = create_agent(tools=tools)
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```
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### 3. 通过 Skills 使用
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创建一个 skill 文件 `skills/web-fetch/SKILL.md`:
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```markdown
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---
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name: web-fetch
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emoji: 🌐
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always: true
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---
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# 网页内容获取
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使用 web_fetch 工具获取网页内容。
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## 使用场景
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- 需要读取某个网页的内容
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- 需要提取文章正文
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- 需要获取网页信息
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## 示例
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<example>
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用户: 帮我看看 https://example.com 这个网页讲了什么
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助手: <tool_use name="web_fetch">
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<url>https://example.com</url>
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<extract_mode>markdown</extract_mode>
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</tool_use>
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</example>
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```
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## 参数说明
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| 参数 | 类型 | 必需 | 默认值 | 说明 |
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|------|------|------|--------|------|
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| `url` | string | ✅ | - | 要抓取的 URL(http/https) |
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| `extract_mode` | string | ❌ | `markdown` | 提取模式:`markdown` 或 `text` |
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| `max_chars` | integer | ❌ | `50000` | 最大返回字符数(最小 100) |
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## 返回结果
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```python
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{
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"url": "https://example.com", # 最终 URL(处理重定向后)
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"status": 200, # HTTP 状态码
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"content_type": "text/html", # 内容类型
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"title": "Example Domain", # 页面标题
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"extractor": "readability", # 提取器:readability/basic/raw
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"extract_mode": "markdown", # 提取模式
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"text": "# Example Domain\n\n...", # 提取的文本内容
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"length": 1234, # 文本长度
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"truncated": false, # 是否被截断
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"warning": "..." # 警告信息(如果有)
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||||
}
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```
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||||
|
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## 与其他搜索工具的对比
|
||||
|
||||
| 工具 | 需要 API Key | 功能 | 成本 |
|
||||
|------|-------------|------|------|
|
||||
| `web_fetch` | ❌ 不需要 | 抓取指定 URL 的内容 | 免费 |
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||||
| `web_search` (Brave) | ✅ 需要 | 搜索引擎查询 | 有免费额度 |
|
||||
| `web_search` (Perplexity) | ✅ 需要 | AI 搜索 + 引用 | 付费 |
|
||||
| `browser` | ❌ 不需要 | 完整浏览器自动化 | 免费但资源占用大 |
|
||||
| `google_search` | ✅ 需要 | Google 搜索 API | 付费 |
|
||||
|
||||
## 技术细节
|
||||
|
||||
### 内容提取策略
|
||||
|
||||
1. **Readability 模式**(推荐)
|
||||
- 使用 Mozilla 的 Readability 算法
|
||||
- 自动识别文章主体内容
|
||||
- 过滤广告、导航栏等噪音
|
||||
|
||||
2. **Basic 模式**(降级)
|
||||
- 简单的 HTML 标签清理
|
||||
- 正则表达式提取文本
|
||||
- 适用于简单页面
|
||||
|
||||
3. **Raw 模式**
|
||||
- 用于非 HTML 内容
|
||||
- 直接返回原始内容
|
||||
|
||||
### 错误处理
|
||||
|
||||
工具会自动处理以下情况:
|
||||
- ✅ HTTP 重定向(最多 3 次)
|
||||
- ✅ 请求超时(默认 30 秒)
|
||||
- ✅ 网络错误自动重试
|
||||
- ✅ 内容提取失败降级
|
||||
|
||||
## 测试
|
||||
|
||||
运行测试脚本:
|
||||
|
||||
```bash
|
||||
cd agent/tools/web_fetch
|
||||
python test_web_fetch.py
|
||||
```
|
||||
|
||||
## 配置选项
|
||||
|
||||
在创建工具时可以传入配置:
|
||||
|
||||
```python
|
||||
tool = WebFetch(config={
|
||||
"timeout": 30, # 请求超时时间(秒)
|
||||
"max_redirects": 3, # 最大重定向次数
|
||||
"user_agent": "..." # 自定义 User-Agent
|
||||
})
|
||||
```
|
||||
|
||||
## 常见问题
|
||||
|
||||
### Q: 为什么推荐安装 readability-lxml?
|
||||
|
||||
A: readability-lxml 提供更好的内容提取质量,能够:
|
||||
- 自动识别文章主体
|
||||
- 过滤广告和导航栏
|
||||
- 保留文章结构
|
||||
|
||||
没有它也能工作,但提取质量会下降。
|
||||
|
||||
### Q: 与 clawdbot 的 web_fetch 有什么区别?
|
||||
|
||||
A: 本实现参考了 clawdbot 的设计,主要区别:
|
||||
- Python 实现(clawdbot 是 TypeScript)
|
||||
- 简化了一些高级特性(如 Firecrawl 集成)
|
||||
- 保留了核心的免费功能
|
||||
- 更容易集成到现有项目
|
||||
|
||||
### Q: 可以抓取需要登录的页面吗?
|
||||
|
||||
A: 当前版本不支持。如需抓取需要登录的页面,请使用 `browser` 工具。
|
||||
|
||||
## 参考
|
||||
|
||||
- [Mozilla Readability](https://github.com/mozilla/readability)
|
||||
- [Clawdbot Web Tools](https://github.com/moltbot/moltbot)
|
||||
3
agent/tools/web_fetch/__init__.py
Normal file
3
agent/tools/web_fetch/__init__.py
Normal file
@@ -0,0 +1,3 @@
|
||||
from .web_fetch import WebFetch
|
||||
|
||||
__all__ = ['WebFetch']
|
||||
47
agent/tools/web_fetch/install_deps.sh
Normal file
47
agent/tools/web_fetch/install_deps.sh
Normal file
@@ -0,0 +1,47 @@
|
||||
#!/bin/bash
|
||||
|
||||
# WebFetch 工具依赖安装脚本
|
||||
|
||||
echo "=================================="
|
||||
echo "WebFetch 工具依赖安装"
|
||||
echo "=================================="
|
||||
echo ""
|
||||
|
||||
# 检查 Python 版本
|
||||
python_version=$(python3 --version 2>&1 | awk '{print $2}')
|
||||
echo "✓ Python 版本: $python_version"
|
||||
echo ""
|
||||
|
||||
# 安装基础依赖
|
||||
echo "📦 安装基础依赖..."
|
||||
python3 -m pip install requests
|
||||
|
||||
# 检查是否成功
|
||||
if [ $? -eq 0 ]; then
|
||||
echo "✅ requests 安装成功"
|
||||
else
|
||||
echo "❌ requests 安装失败"
|
||||
exit 1
|
||||
fi
|
||||
|
||||
echo ""
|
||||
|
||||
# 安装推荐依赖
|
||||
echo "📦 安装推荐依赖(提升内容提取质量)..."
|
||||
python3 -m pip install readability-lxml html2text
|
||||
|
||||
# 检查是否成功
|
||||
if [ $? -eq 0 ]; then
|
||||
echo "✅ readability-lxml 和 html2text 安装成功"
|
||||
else
|
||||
echo "⚠️ 推荐依赖安装失败,但不影响基础功能"
|
||||
fi
|
||||
|
||||
echo ""
|
||||
echo "=================================="
|
||||
echo "安装完成!"
|
||||
echo "=================================="
|
||||
echo ""
|
||||
echo "运行测试:"
|
||||
echo " python3 agent/tools/web_fetch/test_web_fetch.py"
|
||||
echo ""
|
||||
100
agent/tools/web_fetch/test_web_fetch.py
Normal file
100
agent/tools/web_fetch/test_web_fetch.py
Normal file
@@ -0,0 +1,100 @@
|
||||
"""
|
||||
Test script for WebFetch tool
|
||||
"""
|
||||
|
||||
import sys
|
||||
from pathlib import Path
|
||||
|
||||
# Add parent directory to path
|
||||
sys.path.insert(0, str(Path(__file__).parent.parent.parent.parent))
|
||||
|
||||
from agent.tools.web_fetch import WebFetch
|
||||
|
||||
|
||||
def test_web_fetch():
|
||||
"""Test WebFetch tool"""
|
||||
|
||||
print("=" * 80)
|
||||
print("Testing WebFetch Tool")
|
||||
print("=" * 80)
|
||||
|
||||
# Create tool instance
|
||||
tool = WebFetch()
|
||||
|
||||
print(f"\n✅ Tool created: {tool.name}")
|
||||
print(f" Description: {tool.description}")
|
||||
|
||||
# Test 1: Fetch a simple webpage
|
||||
print("\n" + "-" * 80)
|
||||
print("Test 1: Fetching example.com")
|
||||
print("-" * 80)
|
||||
|
||||
result = tool.execute({
|
||||
"url": "https://example.com",
|
||||
"extract_mode": "text",
|
||||
"max_chars": 1000
|
||||
})
|
||||
|
||||
if result.status == "success":
|
||||
print("✅ Success!")
|
||||
data = result.result
|
||||
print(f" Title: {data.get('title', 'N/A')}")
|
||||
print(f" Status: {data.get('status')}")
|
||||
print(f" Extractor: {data.get('extractor')}")
|
||||
print(f" Length: {data.get('length')} chars")
|
||||
print(f" Truncated: {data.get('truncated')}")
|
||||
print(f"\n Content preview:")
|
||||
print(f" {data.get('text', '')[:200]}...")
|
||||
else:
|
||||
print(f"❌ Failed: {result.result}")
|
||||
|
||||
# Test 2: Invalid URL
|
||||
print("\n" + "-" * 80)
|
||||
print("Test 2: Testing invalid URL")
|
||||
print("-" * 80)
|
||||
|
||||
result = tool.execute({
|
||||
"url": "not-a-valid-url"
|
||||
})
|
||||
|
||||
if result.status == "error":
|
||||
print(f"✅ Correctly rejected invalid URL: {result.result}")
|
||||
else:
|
||||
print(f"❌ Should have rejected invalid URL")
|
||||
|
||||
# Test 3: Test with a real webpage (optional)
|
||||
print("\n" + "-" * 80)
|
||||
print("Test 3: Fetching a real webpage (Python.org)")
|
||||
print("-" * 80)
|
||||
|
||||
result = tool.execute({
|
||||
"url": "https://www.python.org",
|
||||
"extract_mode": "markdown",
|
||||
"max_chars": 2000
|
||||
})
|
||||
|
||||
if result.status == "success":
|
||||
print("✅ Success!")
|
||||
data = result.result
|
||||
print(f" Title: {data.get('title', 'N/A')}")
|
||||
print(f" Status: {data.get('status')}")
|
||||
print(f" Extractor: {data.get('extractor')}")
|
||||
print(f" Length: {data.get('length')} chars")
|
||||
print(f" Truncated: {data.get('truncated')}")
|
||||
if data.get('warning'):
|
||||
print(f" ⚠️ Warning: {data.get('warning')}")
|
||||
print(f"\n Content preview:")
|
||||
print(f" {data.get('text', '')[:300]}...")
|
||||
else:
|
||||
print(f"❌ Failed: {result.result}")
|
||||
|
||||
# Close the tool
|
||||
tool.close()
|
||||
|
||||
print("\n" + "=" * 80)
|
||||
print("Testing complete!")
|
||||
print("=" * 80)
|
||||
|
||||
|
||||
if __name__ == "__main__":
|
||||
test_web_fetch()
|
||||
365
agent/tools/web_fetch/web_fetch.py
Normal file
365
agent/tools/web_fetch/web_fetch.py
Normal file
@@ -0,0 +1,365 @@
|
||||
"""
|
||||
Web Fetch tool - Fetch and extract readable content from URLs
|
||||
Supports HTML to Markdown/Text conversion using Mozilla's Readability
|
||||
"""
|
||||
|
||||
import os
|
||||
import re
|
||||
from typing import Dict, Any, Optional
|
||||
from urllib.parse import urlparse
|
||||
import requests
|
||||
from requests.adapters import HTTPAdapter
|
||||
from urllib3.util.retry import Retry
|
||||
|
||||
from agent.tools.base_tool import BaseTool, ToolResult
|
||||
from common.log import logger
|
||||
|
||||
|
||||
class WebFetch(BaseTool):
|
||||
"""Tool for fetching and extracting readable content from web pages"""
|
||||
|
||||
name: str = "web_fetch"
|
||||
description: str = "Fetch and extract readable content from a URL (HTML → markdown/text). Use for lightweight page access without browser automation. Returns title, content, and metadata."
|
||||
|
||||
params: dict = {
|
||||
"type": "object",
|
||||
"properties": {
|
||||
"url": {
|
||||
"type": "string",
|
||||
"description": "HTTP or HTTPS URL to fetch"
|
||||
},
|
||||
"extract_mode": {
|
||||
"type": "string",
|
||||
"description": "Extraction mode: 'markdown' (default) or 'text'",
|
||||
"enum": ["markdown", "text"],
|
||||
"default": "markdown"
|
||||
},
|
||||
"max_chars": {
|
||||
"type": "integer",
|
||||
"description": "Maximum characters to return (default: 50000)",
|
||||
"minimum": 100,
|
||||
"default": 50000
|
||||
}
|
||||
},
|
||||
"required": ["url"]
|
||||
}
|
||||
|
||||
def __init__(self, config: dict = None):
|
||||
self.config = config or {}
|
||||
self.timeout = self.config.get("timeout", 30)
|
||||
self.max_redirects = self.config.get("max_redirects", 3)
|
||||
self.user_agent = self.config.get(
|
||||
"user_agent",
|
||||
"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36"
|
||||
)
|
||||
|
||||
# Setup session with retry strategy
|
||||
self.session = self._create_session()
|
||||
|
||||
# Check if readability-lxml is available
|
||||
self.readability_available = self._check_readability()
|
||||
|
||||
def _create_session(self) -> requests.Session:
|
||||
"""Create a requests session with retry strategy"""
|
||||
session = requests.Session()
|
||||
|
||||
# Retry strategy - handles failed requests, not redirects
|
||||
retry_strategy = Retry(
|
||||
total=3,
|
||||
backoff_factor=1,
|
||||
status_forcelist=[429, 500, 502, 503, 504],
|
||||
allowed_methods=["GET", "HEAD"]
|
||||
)
|
||||
|
||||
# HTTPAdapter handles retries; requests handles redirects via allow_redirects
|
||||
adapter = HTTPAdapter(max_retries=retry_strategy)
|
||||
session.mount("http://", adapter)
|
||||
session.mount("https://", adapter)
|
||||
|
||||
# Set max redirects on session
|
||||
session.max_redirects = self.max_redirects
|
||||
|
||||
return session
|
||||
|
||||
def _check_readability(self) -> bool:
|
||||
"""Check if readability-lxml is available"""
|
||||
try:
|
||||
from readability import Document
|
||||
return True
|
||||
except ImportError:
|
||||
logger.warning(
|
||||
"readability-lxml not installed. Install with: pip install readability-lxml\n"
|
||||
"Falling back to basic HTML extraction."
|
||||
)
|
||||
return False
|
||||
|
||||
def execute(self, args: Dict[str, Any]) -> ToolResult:
|
||||
"""
|
||||
Execute web fetch operation
|
||||
|
||||
:param args: Contains url, extract_mode, and max_chars parameters
|
||||
:return: Extracted content or error message
|
||||
"""
|
||||
url = args.get("url", "").strip()
|
||||
extract_mode = args.get("extract_mode", "markdown").lower()
|
||||
max_chars = args.get("max_chars", 50000)
|
||||
|
||||
if not url:
|
||||
return ToolResult.fail("Error: url parameter is required")
|
||||
|
||||
# Validate URL
|
||||
if not self._is_valid_url(url):
|
||||
return ToolResult.fail(f"Error: Invalid URL (must be http or https): {url}")
|
||||
|
||||
# Validate extract_mode
|
||||
if extract_mode not in ["markdown", "text"]:
|
||||
extract_mode = "markdown"
|
||||
|
||||
# Validate max_chars
|
||||
if not isinstance(max_chars, int) or max_chars < 100:
|
||||
max_chars = 50000
|
||||
|
||||
try:
|
||||
# Fetch the URL
|
||||
response = self._fetch_url(url)
|
||||
|
||||
# Extract content
|
||||
result = self._extract_content(
|
||||
html=response.text,
|
||||
url=response.url,
|
||||
status_code=response.status_code,
|
||||
content_type=response.headers.get("content-type", ""),
|
||||
extract_mode=extract_mode,
|
||||
max_chars=max_chars
|
||||
)
|
||||
|
||||
return ToolResult.success(result)
|
||||
|
||||
except requests.exceptions.Timeout:
|
||||
return ToolResult.fail(f"Error: Request timeout after {self.timeout} seconds")
|
||||
except requests.exceptions.TooManyRedirects:
|
||||
return ToolResult.fail(f"Error: Too many redirects (limit: {self.max_redirects})")
|
||||
except requests.exceptions.RequestException as e:
|
||||
return ToolResult.fail(f"Error fetching URL: {str(e)}")
|
||||
except Exception as e:
|
||||
logger.error(f"Web fetch error: {e}", exc_info=True)
|
||||
return ToolResult.fail(f"Error: {str(e)}")
|
||||
|
||||
def _is_valid_url(self, url: str) -> bool:
|
||||
"""Validate URL format"""
|
||||
try:
|
||||
result = urlparse(url)
|
||||
return result.scheme in ["http", "https"] and bool(result.netloc)
|
||||
except Exception:
|
||||
return False
|
||||
|
||||
def _fetch_url(self, url: str) -> requests.Response:
|
||||
"""
|
||||
Fetch URL with proper headers and error handling
|
||||
|
||||
:param url: URL to fetch
|
||||
:return: Response object
|
||||
"""
|
||||
headers = {
|
||||
"User-Agent": self.user_agent,
|
||||
"Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
|
||||
"Accept-Language": "en-US,en;q=0.9,zh-CN,zh;q=0.8",
|
||||
"Accept-Encoding": "gzip, deflate",
|
||||
"Connection": "keep-alive",
|
||||
}
|
||||
|
||||
# Note: requests library handles redirects automatically
|
||||
# The max_redirects is set in the session's adapter (HTTPAdapter)
|
||||
response = self.session.get(
|
||||
url,
|
||||
headers=headers,
|
||||
timeout=self.timeout,
|
||||
allow_redirects=True
|
||||
)
|
||||
|
||||
response.raise_for_status()
|
||||
return response
|
||||
|
||||
def _extract_content(
|
||||
self,
|
||||
html: str,
|
||||
url: str,
|
||||
status_code: int,
|
||||
content_type: str,
|
||||
extract_mode: str,
|
||||
max_chars: int
|
||||
) -> Dict[str, Any]:
|
||||
"""
|
||||
Extract readable content from HTML
|
||||
|
||||
:param html: HTML content
|
||||
:param url: Original URL
|
||||
:param status_code: HTTP status code
|
||||
:param content_type: Content type header
|
||||
:param extract_mode: 'markdown' or 'text'
|
||||
:param max_chars: Maximum characters to return
|
||||
:return: Extracted content and metadata
|
||||
"""
|
||||
# Check content type
|
||||
if "text/html" not in content_type.lower():
|
||||
# Non-HTML content
|
||||
text = html[:max_chars]
|
||||
truncated = len(html) > max_chars
|
||||
|
||||
return {
|
||||
"url": url,
|
||||
"status": status_code,
|
||||
"content_type": content_type,
|
||||
"extractor": "raw",
|
||||
"text": text,
|
||||
"length": len(text),
|
||||
"truncated": truncated,
|
||||
"message": f"Non-HTML content (type: {content_type})"
|
||||
}
|
||||
|
||||
# Extract readable content from HTML
|
||||
if self.readability_available:
|
||||
return self._extract_with_readability(
|
||||
html, url, status_code, content_type, extract_mode, max_chars
|
||||
)
|
||||
else:
|
||||
return self._extract_basic(
|
||||
html, url, status_code, content_type, extract_mode, max_chars
|
||||
)
|
||||
|
||||
def _extract_with_readability(
|
||||
self,
|
||||
html: str,
|
||||
url: str,
|
||||
status_code: int,
|
||||
content_type: str,
|
||||
extract_mode: str,
|
||||
max_chars: int
|
||||
) -> Dict[str, Any]:
|
||||
"""Extract content using Mozilla's Readability"""
|
||||
try:
|
||||
from readability import Document
|
||||
|
||||
# Parse with Readability
|
||||
doc = Document(html)
|
||||
title = doc.title()
|
||||
content_html = doc.summary()
|
||||
|
||||
# Convert to markdown or text
|
||||
if extract_mode == "markdown":
|
||||
text = self._html_to_markdown(content_html)
|
||||
else:
|
||||
text = self._html_to_text(content_html)
|
||||
|
||||
# Truncate if needed
|
||||
truncated = len(text) > max_chars
|
||||
if truncated:
|
||||
text = text[:max_chars]
|
||||
|
||||
return {
|
||||
"url": url,
|
||||
"status": status_code,
|
||||
"content_type": content_type,
|
||||
"title": title,
|
||||
"extractor": "readability",
|
||||
"extract_mode": extract_mode,
|
||||
"text": text,
|
||||
"length": len(text),
|
||||
"truncated": truncated
|
||||
}
|
||||
|
||||
except Exception as e:
|
||||
logger.warning(f"Readability extraction failed: {e}")
|
||||
# Fallback to basic extraction
|
||||
return self._extract_basic(
|
||||
html, url, status_code, content_type, extract_mode, max_chars
|
||||
)
|
||||
|
||||
def _extract_basic(
|
||||
self,
|
||||
html: str,
|
||||
url: str,
|
||||
status_code: int,
|
||||
content_type: str,
|
||||
extract_mode: str,
|
||||
max_chars: int
|
||||
) -> Dict[str, Any]:
|
||||
"""Basic HTML extraction without Readability"""
|
||||
# Extract title
|
||||
title_match = re.search(r'<title[^>]*>(.*?)</title>', html, re.IGNORECASE | re.DOTALL)
|
||||
title = title_match.group(1).strip() if title_match else "Untitled"
|
||||
|
||||
# Remove script and style tags
|
||||
text = re.sub(r'<script[^>]*>.*?</script>', '', html, flags=re.DOTALL | re.IGNORECASE)
|
||||
text = re.sub(r'<style[^>]*>.*?</style>', '', text, flags=re.DOTALL | re.IGNORECASE)
|
||||
|
||||
# Remove HTML tags
|
||||
text = re.sub(r'<[^>]+>', ' ', text)
|
||||
|
||||
# Clean up whitespace
|
||||
text = re.sub(r'\s+', ' ', text)
|
||||
text = text.strip()
|
||||
|
||||
# Truncate if needed
|
||||
truncated = len(text) > max_chars
|
||||
if truncated:
|
||||
text = text[:max_chars]
|
||||
|
||||
return {
|
||||
"url": url,
|
||||
"status": status_code,
|
||||
"content_type": content_type,
|
||||
"title": title,
|
||||
"extractor": "basic",
|
||||
"extract_mode": extract_mode,
|
||||
"text": text,
|
||||
"length": len(text),
|
||||
"truncated": truncated,
|
||||
"warning": "Using basic extraction. Install readability-lxml for better results."
|
||||
}
|
||||
|
||||
def _html_to_markdown(self, html: str) -> str:
|
||||
"""Convert HTML to Markdown (basic implementation)"""
|
||||
try:
|
||||
# Try to use html2text if available
|
||||
import html2text
|
||||
h = html2text.HTML2Text()
|
||||
h.ignore_links = False
|
||||
h.ignore_images = False
|
||||
h.body_width = 0 # Don't wrap lines
|
||||
return h.handle(html)
|
||||
except ImportError:
|
||||
# Fallback to basic conversion
|
||||
return self._html_to_text(html)
|
||||
|
||||
def _html_to_text(self, html: str) -> str:
|
||||
"""Convert HTML to plain text"""
|
||||
# Remove script and style tags
|
||||
text = re.sub(r'<script[^>]*>.*?</script>', '', html, flags=re.DOTALL | re.IGNORECASE)
|
||||
text = re.sub(r'<style[^>]*>.*?</style>', '', text, flags=re.DOTALL | re.IGNORECASE)
|
||||
|
||||
# Convert common tags to text equivalents
|
||||
text = re.sub(r'<br\s*/?>', '\n', text, flags=re.IGNORECASE)
|
||||
text = re.sub(r'<p[^>]*>', '\n\n', text, flags=re.IGNORECASE)
|
||||
text = re.sub(r'</p>', '', text, flags=re.IGNORECASE)
|
||||
text = re.sub(r'<h[1-6][^>]*>', '\n\n', text, flags=re.IGNORECASE)
|
||||
text = re.sub(r'</h[1-6]>', '\n', text, flags=re.IGNORECASE)
|
||||
|
||||
# Remove all other HTML tags
|
||||
text = re.sub(r'<[^>]+>', '', text)
|
||||
|
||||
# Decode HTML entities
|
||||
import html
|
||||
text = html.unescape(text)
|
||||
|
||||
# Clean up whitespace
|
||||
text = re.sub(r'\n\s*\n\s*\n+', '\n\n', text)
|
||||
text = re.sub(r' +', ' ', text)
|
||||
text = text.strip()
|
||||
|
||||
return text
|
||||
|
||||
def close(self):
|
||||
"""Close the session"""
|
||||
if hasattr(self, 'session'):
|
||||
self.session.close()
|
||||
Reference in New Issue
Block a user