主题
MCP DSL 集成
了解如何使用 CrewAI 简单的 DSL 语法,通过 mcps 字段将 MCP 服务器直接集成到你的智能体中。
概述
CrewAI 的 MCP DSL(领域特定语言)集成提供了将智能体连接到 MCP(Model Context Protocol)服务器的最简单方式。只需在智能体中添加 mcps 字段,CrewAI 就会自动处理所有复杂性。
INFO
对于大多数 MCP 用例,这是推荐方法。对于需要手动连接管理的高级 场景,请参阅 MCPServerAdapter。
基本用法
使用 mcps 字段向你的智能体添加 MCP 服务器:
python
from crewai import Agent
agent = Agent(
role="Research Assistant",
goal="Help with research and analysis tasks",
backstory="Expert assistant with access to advanced research tools",
mcps=[
"https://mcp.exa.ai/mcp?api_key=your_key&profile=research"
]
)
# MCP tools are now automatically available!
# No need for manual connection management or tool configuration支持的引用格式
外部 MCP 远程服务器
python
# Basic HTTPS server
"https://api.example.com/mcp"
# Server with authentication
"https://mcp.exa.ai/mcp?api_key=your_key&profile=your_profile"
# Server with custom path
"https://services.company.com/api/v1/mcp"选择特定工具
使用 # 语法从服务器中选择特定工具:
python
# Get only the forecast tool from weather server
"https://weather.api.com/mcp#get_forecast"
# Get only the search tool from Exa
"https://mcp.exa.ai/mcp?api_key=your_key#web_search_exa"已连接的 MCP 集成
从 CrewAI 目录连接 MCP 服务器,或自带服务器。在账户中连接后,可通过 slug 引用它们:
python
# Connected MCP with all tools
"snowflake"
# Specific tool from a connected MCP
"stripe#list_invoices"
# Multiple connected MCPs
mcps=[
"snowflake",
"stripe",
"github"
]完整示例
以下是一个使用多个 MCP 服务器的完整示例:
python
from crewai import Agent, Task, Crew, Process
# Create agent with multiple MCP sources
multi_source_agent = Agent(
role="Multi-Source Research Analyst",
goal="Conduct comprehensive research using multiple data sources",
backstory="""Expert researcher with access to web search, weather data,
financial information, and academic research tools""",
mcps=[
# External MCP servers
"https://mcp.exa.ai/mcp?api_key=your_exa_key&profile=research",
"https://weather.api.com/mcp#get_current_conditions",
# Connected MCPs from catalog
"snowflake",
"stripe#list_invoices",
"github#search_repositories"
]
)
# Create comprehensive research task
research_task = Task(
description="""Research the impact of AI agents on business productivity.
Include current weather impacts on remote work, financial market trends,
and recent academic publications on AI agent frameworks.""",
expected_output="""Comprehensive report covering:
1. AI agent business impact analysis
2. Weather considerations for remote work
3. Financial market trends related to AI
4. Academic research citations and insights
5. Competitive landscape analysis""",
agent=multi_source_agent
)
# Create and execute crew
research_crew = Crew(
agents=[multi_source_agent],
tasks=[research_task],
process=Process.sequential,
verbose=True
)
result = research_crew.kickoff()
print(f"Research completed with {len(multi_source_agent.mcps)} MCP data sources")工具命名与组织
CrewAI 会自动处理工具命名以避免冲突:
python
# Original MCP server has tools: "search", "analyze"
# CrewAI creates tools: "mcp_exa_ai_search", "mcp_exa_ai_analyze"
agent = Agent(
role="Tool Organization Demo",
goal="Show how tool naming works",
backstory="Demonstrates automatic tool organization",
mcps=[
"https://mcp.exa.ai/mcp?api_key=key", # Tools: mcp_exa_ai_*
"https://weather.service.com/mcp", # Tools: weather_service_com_*
"snowflake" # Tools: snowflake_*
]
)
# Each server's tools get unique prefixes based on the server name
# This prevents naming conflicts between different MCP servers错误处理与容错
MCP DSL 的设计目标是稳健且用户友好:
优雅处理服务器故障
python
agent = Agent(
role="Resilient Researcher",
goal="Research despite server issues",
backstory="Experienced researcher who adapts to available tools",
mcps=[
"https://primary-server.com/mcp", # Primary data source
"https://backup-server.com/mcp", # Backup if primary fails
"https://unreachable-server.com/mcp", # Will be skipped with warning
"snowflake" # Connected MCP from catalog
]
)
# Agent will:
# 1. Successfully connect to working servers
# 2. Log warnings for failing servers
# 3. Continue with available tools
# 4. Not crash or hang on server failures超时保护
所有 MCP 操作都内置超时:
- 连接超时:10 秒
- 工具执行超时:30 秒
- 发现超时:15 秒
python
# These servers will timeout gracefully if unresponsive
mcps=[
"https://slow-server.com/mcp", # Will timeout after 10s if unresponsive
"https://overloaded-api.com/mcp" # Will timeout if discovery takes > 15s
]性能特性
自动缓存
工具 schema 会被缓存 5 分钟以提升性能:
python
# First agent creation - discovers tools from server
agent1 = Agent(role="First", goal="Test", backstory="Test",
mcps=["https://api.example.com/mcp"])
# Second agent creation (within 5 minutes) - uses cached tool schemas
agent2 = Agent(role="Second", goal="Test", backstory="Test",
mcps=["https://api.example.com/mcp"]) # Much faster!按需连接
仅在工具实际使用时才建立工具连接:
python
# Agent creation is fast - no MCP connections made yet
agent = Agent(
role="On-Demand Agent",
goal="Use tools efficiently",
backstory="Efficient agent that connects only when needed",
mcps=["https://api.example.com/mcp"]
)
# MCP connection is made only when a tool is actually executed
# This minimizes connection overhead and improves startup performance与现有功能的集成
MCP 工具可与其他 CrewAI 功能无缝协作:
python
from crewai.tools import BaseTool
class CustomTool(BaseTool):
name: str = "custom_analysis"
description: str = "Custom analysis tool"
def _run(self, **kwargs):
return "Custom analysis result"
agent = Agent(
role="Full-Featured Agent",
goal="Use all available tool types",
backstory="Agent with comprehensive tool access",
# All tool types work together
tools=[CustomTool()], # Custom tools
apps=["gmail", "slack"], # Platform integrations
mcps=[ # MCP servers
"https://mcp.exa.ai/mcp?api_key=key",
"snowflake"
],
verbose=True,
max_iter=15
)最佳实践
1. 尽可能使用特定工具
python
# Good - only get the tools you need
mcps=["https://weather.api.com/mcp#get_forecast"]
# Less efficient - gets all tools from server
mcps=["https://weather.api.com/mcp"]2. 安全地处理身份认证
python
import os
# Store API keys in environment variables
exa_key = os.getenv("EXA_API_KEY")
exa_profile = os.getenv("EXA_PROFILE")
agent = Agent(
role="Secure Agent",
goal="Use MCP tools securely",
backstory="Security-conscious agent",
mcps=[f"https://mcp.exa.ai/mcp?api_key={exa_key}&profile={exa_profile}"]
)3. 为服务器故障做好规划
python
# Always include backup options
mcps=[
"https://primary-api.com/mcp", # Primary choice
"https://backup-api.com/mcp", # Backup option
"snowflake" # Connected MCP fallback
]4. 使用描述性的智能体角色
python
agent = Agent(
role="Weather-Enhanced Market Analyst",
goal="Analyze markets considering weather impacts",
backstory="Financial analyst with access to weather data for agricultural market insights",
mcps=[
"https://weather.service.com/mcp#get_forecast",
"stripe#list_invoices"
]
)故障排查
常见问题
未发现工具:
python
# Check your MCP server URL and authentication
# Verify the server is running and accessible
mcps=["https://mcp.example.com/mcp?api_key=valid_key"]连接超时:
python
# Server may be slow or overloaded
# CrewAI will log warnings and continue with other servers
# Check server status or try backup servers身份认证失败:
python
# Verify API keys and credentials
# Check server documentation for required parameters
# Ensure query parameters are properly URL encoded高级:MCPServerAdapter
对于需要手动连接管理的复杂场景,请使用 crewai-tools 中的 MCPServerAdapter 类。推荐使用 Python 上下文管理器(with 语句),因为它会自动处理与 MCP 服务器连接的启动和停止。