在当今快速发展的AI领域,将大型语言模型(LLM)与实际应用场景相结合已成为提升生产力的关键。然而,LLM本身存在局限性——它们无法直接与现实世界交互、操作应用程序或执行复杂的工作流。这就是为什么我们需要像Playwright MCP这样的工具来弥合这一差距。
本文将深入探讨如何利用Playwright MCP(Model Context Protocol)与LLM协同工作,构建能够处理复杂任务的工作流和智能AI代理。
什么是Playwright MCP?
Playwright MCP是一个基于Model Context Protocol的桥接工具,它将强大的浏览器自动化框架Playwright与LLM连接起来。MCP协议允许LLM访问外部工具和资源,而Playwright则提供了跨浏览器的自动化能力。
核心组件
- Playwright: Microsoft开发的跨浏览器自动化工具,支持Chromium**、Firefox和WebKit
- MCP Server: 处理LLM与Playwright之间的通信
- LLM接口: 提供自然语言理解和任务规划能力
环境设置与安装
prerequisites
- Node.js 16+
- Python 3.8+
- 访问LLM API(如OpenAI GPT、Claude等)
安装步骤
# 安装Playwright
npm install playwright
npx playwright install
# 安装MCP相关依赖
pip install mcp-client playwright-async
# 克隆Playwright MCP仓库
git clone https://github.com/your-repo/playwright-mcp.git
cd playwright-mcp
基础配置
# config.py
import os
from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client
class PlaywrightMCPConfig:
def __init__(self):
self.browser_type = "chromium"# chromium, firefox, webkit
self.headless = False
self.timeout = 30000
self.llm_api_key = os.getenv("LLM_API_KEY")
def get_server_params(self):
return StdioServerParameters(
command="node",
args=["path/to/playwright-mcp-server.js"]
)
构建基础工作流
1. 初始化连接
import asyncio
from mcp.client.stdio import stdio_client
from mcp import ClientSession
from config import PlaywrightMCPConfig
class PlaywrightMCPClient:
def __init__(self, config: PlaywrightMCPConfig):
self.config = config
self.session = None
asyncdef connect(self):
server_params = self.config.get_server_params()
asyncwith stdio_client(server_params) as (read, write):
asyncwith ClientSession(read, write) as session:
self.session = session
# 初始化会话
await session.initialize()
return self
2. 基本网页操作
class WebAutomationWorkflow:
def __init__(self, mcp_client):
self.client = mcp_client
asyncdef navigate_to_page(self, url: str):
"""导航到指定页面"""
result = await self.client.session.call_tool(
"navigate",
{"url": url}
)
return result
asyncdef fill_form(self, selector: str, value: str):
"""填写表单"""
result = await self.client.session.call_tool(
"fill",
{"selector": selector, "value": value}
)
return result
asyncdef click_element(self, selector: str):
"""点击元素"""
result = await self.client.session.call_tool(
"click",
{"selector": selector}
)
return result
asyncdef extract_text(self, selector: str):
"""提取文本内容"""
result = await self.client.session.call_tool(
"get_text",
{"selector": selector}
)
return result
集成LLM创建智能工作流
1. LLM任务规划器
import openai
from typing import List, Dict, Any
class LLMTaskPlanner:
def __init__(self, api_key: str):
self.client = openai.OpenAI(api_key=api_key)
def plan_workflow(self, user_request: str) -> List[Dict[str, Any]]:
"""使用LLM解析用户请求并生成工作流步骤"""
prompt = f"""
根据以下用户请求,生成一个详细的Playwright自动化工作流。
用户请求: {user_request}
请以JSON格式返回步骤列表,每个步骤包含:
- action: 操作类型 (navigate, click, fill, extract, wait, etc.)
- parameters: 操作参数
- description: 步骤描述
只返回JSON格式的结果。
"""
response = self.client.chat.completions.create(
model="gpt-4",
messages=[{"role": "user", "content": prompt}],
temperature=0.1
)
return self._parse_response(response.choices[0].message.content)
def _parse_response(self, response: str) -> List[Dict[str, Any]]:
"""解析LLM响应为结构化工作流"""
import json
try:
# 清理响应并提取JSON
cleaned_response = response.strip()
if"```json"in cleaned_response:
cleaned_response = cleaned_response.split("```json")[1].split("```")[0]
elif"```"in cleaned_response:
cleaned_response = cleaned_response.split("```")[1]
return json.loads(cleaned_response)
except Exception as e:
print(f"解析LLM响应失败: {e}")
return []
2. 智能工作流执行器
class IntelligentWorkflowExecutor:
def __init__(self, mcp_client, llm_planner):
self.mcp_client = mcp_client
self.planner = llm_planner
self.automation = WebAutomationWorkflow(mcp_client)
asyncdef execute_user_request(self, user_request: str):
"""执行用户自然语言请求的完整工作流"""
print(f"处理用户请求: {user_request}")
# 1. 使用LLM规划工作流
workflow_steps = self.planner.plan_workflow(user_request)
print(f"生成的工作流步骤: {len(workflow_steps)}步")
# 2. 执行工作流
results = []
for i, step in enumerate(workflow_steps, 1):
print(f"执行步骤 {i}: {step['description']}")
try:
result = await self._execute_step(step)
results.append({
"step": i,
"description": step["description"],
"result": result,
"status": "success"
})
except Exception as e:
results.append({
"step": i,
"description": step["description"],
"error": str(e),
"status": "failed"
})
print(f"步骤 {i} 执行失败: {e}")
break
return results
asyncdef _execute_step(self, step: Dict[str, Any]):
"""执行单个工作流步骤"""
action = step["action"]
params = step["parameters"]
if action == "navigate":
returnawait self.automation.navigate_to_page(params["url"])
elif action == "click":
returnawait self.automation.click_element(params["selector"])
elif action == "fill":
returnawait self.automation.fill_form(params["selector"], params["value"])
elif action == "extract":
returnawait self.automation.extract_text(params["selector"])
elif action == "wait":
await asyncio.sleep(params.get("seconds", 2))
return"等待完成"
else:
raise ValueError(f"未知操作: {action}")
高级应用:构建AI智能体
1. 自适应智能体
class AdaptiveAIAgent:
def __init__(self, mcp_client, llm_planner, executor):
self.mcp_client = mcp_client
self.planner = llm_planner
self.executor = executor
self.conversation_history = []
asyncdef process_request(self, user_input: str, context: Dict = None):
"""处理用户输入并执行相应操作"""
# 添加上下文到对话历史
self.conversation_history.append({"role": "user", "content": user_input})
# 分析用户意图
intent = await self._analyze_intent(user_input, context)
if intent["type"] == "automation":
# 执行自动化工作流
results = await self.executor.execute_user_request(user_input)
# 生成自然语言总结
summary = await self._generate_summary(user_input, results)
self.conversation_history.append({
"role": "assistant",
"content": summary
})
return {
"type": "automation",
"results": results,
"summary": summary
}
elif intent["type"] == "query":
# 处理查询请求
response = await self._handle_query(user_input)
return {
"type": "query",
"response": response
}
asyncdef _analyze_intent(self, user_input: str, context: Dict) -> Dict:
"""使用LLM分析用户意图"""
# 简化的意图分析实现
automation_keywords = ["打开", "点击", "填写", "导航", "提取", "自动化"]
if any(keyword in user_input for keyword in automation_keywords):
return {"type": "automation", "confidence": 0.9}
else:
return {"type": "query", "confidence": 0.7}
asyncdef _generate_summary(self, request: str, results: List) -> str:
"""生成工作流执行总结"""
success_steps = [r for r in results if r["status"] == "success"]
returnf"""
已完成您的要求: {request}
执行统计:
- 总步骤数: {len(results)}
- 成功步骤: {len(success_steps)}
- 失败步骤: {len(results) - len(success_steps)}
{'所有步骤均成功完成!' if len(success_steps) == len(results) else '部分步骤执行失败,请检查错误信息。'}
"""
2. 复杂工作流示例:电商数据采集
class EcommerceDataAgent:
def __init__(self, base_agent):
self.agent = base_agent
asyncdef collect_product_data(self, product_url: str, data_points: List[str]):
"""采集电商产品数据"""
workflow_request = f"""
请执行以下电商数据采集任务:
1. 导航到产品页面: {product_url}
2. 提取产品标题
3. 提取产品价格
4. 提取产品评分
5. 提取产品描述
6. 提取客户评论数量
"""
# 执行数据采集
results = await self.agent.process_request(workflow_request)
# 数据清洗和结构化
structured_data = await self._structure_product_data(results)
return structured_data
asyncdef _structure_product_data(self, raw_results: Dict) -> Dict:
"""将采集的数据结构化"""
# 实现数据解析和结构化逻辑
structured = {}
for result in raw_results.get("results", []):
if"result"in result and result["result"]:
# 解析提取的数据
text_content = result["result"].get("content", "")
# 根据步骤描述识别数据类型
if"标题"in result["description"]:
structured["title"] = self._clean_text(text_content)
elif"价格"in result["description"]:
structured["price"] = self._extract_price(text_content)
elif"评分"in result["description"]:
structured["rating"] = self._extract_rating(text_content)
return structured
def _clean_text(self, text: str) -> str:
"""清理文本数据"""
return text.strip() if text else""
def _extract_price(self, text: str) -> float:
"""提取价格信息"""
import re
matches = re.findall(r'[\d.,]+', text)
return float(matches[0].replace(',', '')) if matches else0.0
错误处理与优化
1. 鲁棒性增强
class RobustWorkflowExecutor(IntelligentWorkflowExecutor):
asyncdef execute_with_retry(self, user_request: str, max_retries: int = 3):
"""带重试机制的工作流执行"""
for attempt in range(max_retries):
try:
results = await self.execute_user_request(user_request)
# 检查是否有失败步骤
failed_steps = [r for r in results if r["status"] == "failed"]
ifnot failed_steps:
return results
print(f"第 {attempt + 1} 次尝试,{len(failed_steps)} 个步骤失败")
# 最后一次尝试仍然失败,抛出异常
if attempt == max_retries - 1:
raise Exception(f"工作流执行失败,{len(failed_steps)} 个步骤未完成")
except Exception as e:
print(f"第 {attempt + 1} 次尝试失败: {e}")
if attempt == max_retries - 1:
raise
await asyncio.sleep(2) # 重试前等待
return []
asyncdef _execute_step_with_fallback(self, step: Dict):
"""带备用方案的步骤执行"""
try:
returnawait self._execute_step(step)
except Exception as e:
print(f"步骤执行失败: {e},尝试备用方案")
# 实现备用执行逻辑
if step["action"] == "click":
# 尝试不同的选择器
returnawait self._try_alternative_selectors(step)
elif step["action"] == "extract":
# 尝试不同的数据提取方法
returnawait self._try_alternative_extraction(step)
else:
raise
2. 性能监控
import time
from dataclasses import dataclass
from typing import List
@dataclass
class PerformanceMetrics:
total_steps: int
successful_steps: int
failed_steps: int
total_time: float
average_step_time: float
class PerformanceMonitor:
def __init__(self):
self.metrics_history: List[PerformanceMetrics] = []
def start_execution(self):
self.start_time = time.time()
self.step_times = []
def record_step(self, success: bool, step_time: float):
self.step_times.append(step_time)
def end_execution(self, total_steps: int, successful_steps: int):
total_time = time.time() - self.start_time
avg_time = sum(self.step_times) / len(self.step_times) if self.step_times else0
metrics = PerformanceMetrics(
total_steps=total_steps,
successful_steps=successful_steps,
failed_steps=total_steps - successful_steps,
total_time=total_time,
average_step_time=avg_time
)
self.metrics_history.append(metrics)
return metrics
实际应用场景
1. 自动化测试智能体
class TestingAutomationAgent:
def __init__(self, base_agent):
self.agent = base_agent
async def run_e2e_test(self, test_scenario: str):
"""执行端到端测试"""
test_request = f"""
执行以下端到端测试场景:
{test_scenario}
包括:
1. 导航到测试页面
2. 执行测试步骤
3. 验证预期结果
4. 生成测试报告
"""
return await self.agent.process_request(test_request)
2. 数据监控智能体
class MonitoringAgent:
def __init__(self, base_agent, alert_thresholds: Dict):
self.agent = base_agent
self.thresholds = alert_thresholds
asyncdef monitor_website(self, url: str, check_interval: int = 3600):
"""定期监控网站状态"""
whileTrue:
try:
status = await self._check_website_status(url)
ifnot status["is_healthy"]:
await self._send_alert(f"网站异常: {status['issues']}")
except Exception as e:
await self._send_alert(f"监控检查失败: {e}")
await asyncio.sleep(check_interval)
asyncdef _check_website_status(self, url: str) -> Dict:
"""检查网站健康状态"""
check_request = f"""
检查网站健康状况:
1. 访问 {url}
2. 检查页面加载时间
3. 验证关键功能是否正常
4. 检查错误信息
"""
results = await self.agent.process_request(check_request)
return self._analyze_health_status(results)
结论
通过结合Playwright MCP和LLM,我们能够构建强大的AI智能体和工作流系统,这些系统能够:
- 理解自然语言指令并转化为具体操作
- 自动化复杂业务流程,减少人工干预
- 自适应处理异常情况,提高系统鲁棒性
- 持续学习和优化执行策略
这种技术组合为自动化测试、数据采集、监控警报等场景提供了全新的解决方案。随着AI技术的不断发展,这种模式将在更多领域展现其价值,推动企业数字化转型和智能化升级。
Playwright MCP与LLM的结合只是AI驱动自动化的开始,这个领域的发展潜力无限,值得我们持续关注和探索。
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