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CrewAI Multi-Agent Framework Cheat Sheet

Overview

CrewAI is a revolutionary open-source multi-agent orchestration framework that transforms how developers build and deploy AI-powered applications. Created by João Moura, this Python-based framework enables multiple AI agents to work together as a cohesive unit, each assuming specific roles and sharing responsibilities to accomplish complex tasks that would be challenging for a single agent to handle alone.

What sets CrewAI apart is its ability to orchestrate sophisticated multi-agent systems where agents can autonomously delegate tasks to each other, collaborate on problem-solving, and leverage specialized tools and capabilities. The framework provides both high-level simplicity for quick development and precise low-level control for complex scenarios, making it ideal for creating autonomous AI agents tailored to any business or technical requirement.

CrewAI addresses the growing need for AI systems that can handle multi-faceted challenges by breaking them down into manageable components, assigning specialized agents to each component, and coordinating their efforts to achieve superior results compared to traditional single-agent approaches.

Core Concepts

Agents

Agents are the fundamental building blocks of CrewAI systems. Each agent is designed with specific roles, goals, and capabilities, functioning as autonomous entities that can reason, plan, and execute tasks within their domain of expertise.

Crews

A crew is a collection of agents working together toward a common objective. Crews define the structure and workflow of multi-agent collaboration, establishing how agents interact, delegate tasks, and share information.

Tasks

Tasks represent specific objectives or activities that need to be completed. They can be assigned to individual agents or distributed across multiple agents within a crew, depending on the complexity and requirements.

Tools

Tools extend agent capabilities by providing access to external services, APIs, databases, or specialized functions. Agents can use tools to perform actions beyond their core language model capabilities.

Installation and Setup

Basic Installation

bash
# Install CrewAI using pip
pip install crewai

# Install with additional tools
pip install 'crewai[tools]'

# Install development version
pip install git+https://github.com/crewAIInc/crewAI.git

Environment Setup

python
import os
from crewai import Agent, Task, Crew, Process

# Set up API keys for LLM providers
os.environ["OPENAI_API_KEY"] = "your-openai-api-key"
# or
os.environ["ANTHROPIC_API_KEY"] = "your-anthropic-api-key"
# or other supported providers

Project Structure

my_crew_project/
├── agents/
│   ├── __init__.py
│   ├── researcher.py
│   └── writer.py
├── tasks/
│   ├── __init__.py
│   ├── research_tasks.py
│   └── writing_tasks.py
├── tools/
│   ├── __init__.py
│   └── custom_tools.py
├── crews/
│   ├── __init__.py
│   └── content_crew.py
└── main.py

Agent Configuration

Basic Agent Creation

python
from crewai import Agent

# Create a basic agent
researcher = Agent(
    role='Research Specialist',
    goal='Conduct thorough research on given topics',
    backstory="""You are an experienced researcher with expertise in 
    gathering, analyzing, and synthesizing information from multiple sources. 
    You have a keen eye for detail and can identify reliable sources.""",
    verbose=True,
    allow_delegation=False
)

Advanced Agent Configuration

python
from crewai import Agent
from crewai_tools import SerperDevTool, WebsiteSearchTool

# Create an agent with tools and advanced settings
research_agent = Agent(
    role='Senior Research Analyst',
    goal='Provide comprehensive analysis and insights on market trends',
    backstory="""You are a senior research analyst with 10+ years of experience 
    in market research and competitive analysis. You excel at identifying patterns, 
    trends, and actionable insights from complex data sets.""",
    tools=[SerperDevTool(), WebsiteSearchTool()],
    verbose=True,
    allow_delegation=True,
    max_iter=5,
    memory=True,
    step_callback=lambda step: print(f"Agent step: {step}"),
    system_template="""You are {role}. {backstory}
    Your goal is: {goal}
    Always provide detailed analysis with supporting evidence."""
)

Agent with Custom LLM

python
from langchain.llms import OpenAI
from crewai import Agent

# Use custom LLM configuration
custom_llm = OpenAI(temperature=0.7, model_name="gpt-4")

analyst = Agent(
    role='Data Analyst',
    goal='Analyze data and provide statistical insights',
    backstory='Expert in statistical analysis and data interpretation',
    llm=custom_llm,
    verbose=True
)

Multimodal Agent

python
from crewai import Agent

# Agent with multimodal capabilities
visual_analyst = Agent(
    role='Visual Content Analyst',
    goal='Analyze images and visual content for insights',
    backstory='Specialist in visual content analysis and interpretation',
    multimodal=True,  # Enable multimodal capabilities
    tools=[image_analysis_tool],
    verbose=True
)

Task Definition and Management

Basic Task Creation

python
from crewai import Task

# Define a simple task
research_task = Task(
    description="""Conduct comprehensive research on artificial intelligence 
    trends in 2024. Focus on:
    1. Emerging AI technologies
    2. Market adoption rates
    3. Key industry players
    4. Future predictions
    
    Provide a detailed report with sources and citations.""",
    agent=researcher,
    expected_output="A comprehensive research report with citations"
)

Advanced Task Configuration

python
from crewai import Task

# Task with dependencies and callbacks
analysis_task = Task(
    description="""Analyze the research findings and create strategic 
    recommendations for AI adoption in enterprise environments.""",
    agent=analyst,
    expected_output="Strategic recommendations document with actionable insights",
    context=[research_task],  # Depends on research_task completion
    callback=lambda output: save_to_database(output),
    async_execution=False,
    output_file="analysis_report.md"
)

Task with Custom Output Parsing

python
from crewai import Task
from pydantic import BaseModel
from typing import List

class ResearchOutput(BaseModel):
    title: str
    summary: str
    key_findings: List[str]
    sources: List[str]
    confidence_score: float

structured_task = Task(
    description="Research AI market trends and provide structured output",
    agent=researcher,
    expected_output="Structured research findings",
    output_pydantic=ResearchOutput
)

Conditional Task Execution

python
from crewai import Task

def should_execute_task(context):
    # Custom logic to determine if task should execute
    return len(context.get('findings', [])) > 5

conditional_task = Task(
    description="Perform detailed analysis if sufficient data is available",
    agent=analyst,
    expected_output="Detailed analysis report",
    condition=should_execute_task
)

Crew Orchestration

Basic Crew Setup

python
from crewai import Crew, Process

# Create a basic crew
content_crew = Crew(
    agents=[researcher, writer],
    tasks=[research_task, writing_task],
    verbose=2,
    process=Process.sequential
)

# Execute the crew
result = content_crew.kickoff()
print(result)

Advanced Crew Configuration

python
from crewai import Crew, Process
from crewai.memory import LongTermMemory

# Advanced crew with memory and custom settings
advanced_crew = Crew(
    agents=[researcher, analyst, writer, reviewer],
    tasks=[research_task, analysis_task, writing_task, review_task],
    process=Process.hierarchical,
    memory=LongTermMemory(),
    verbose=2,
    manager_llm=manager_llm,
    function_calling_llm=function_llm,
    max_rpm=10,
    share_crew=True,
    step_callback=crew_step_callback,
    task_callback=crew_task_callback
)

Hierarchical Process

python
from crewai import Crew, Process, Agent

# Manager agent for hierarchical process
manager = Agent(
    role='Project Manager',
    goal='Coordinate team activities and ensure quality deliverables',
    backstory='Experienced project manager with strong leadership skills',
    allow_delegation=True
)

hierarchical_crew = Crew(
    agents=[manager, researcher, analyst, writer],
    tasks=[research_task, analysis_task, writing_task],
    process=Process.hierarchical,
    manager_agent=manager,
    verbose=2
)

Parallel Task Execution

python
from crewai import Crew, Process

# Crew with parallel task execution
parallel_crew = Crew(
    agents=[researcher1, researcher2, researcher3],
    tasks=[task1, task2, task3],
    process=Process.sequential,  # Overall sequential, but tasks can run in parallel
    max_execution_time=3600,  # 1 hour timeout
    verbose=2
)

# Execute with parallel capabilities
result = parallel_crew.kickoff(inputs={
    'topic': 'AI in Healthcare',
    'deadline': '2024-12-31'
})

Tool Integration

Built-in Tools

python
from crewai_tools import (
    SerperDevTool,
    WebsiteSearchTool,
    FileReadTool,
    DirectoryReadTool,
    CodeDocsSearchTool,
    YoutubeVideoSearchTool
)

# Configure built-in tools
search_tool = SerperDevTool()
web_tool = WebsiteSearchTool()
file_tool = FileReadTool()
code_tool = CodeDocsSearchTool()

# Agent with multiple tools
multi_tool_agent = Agent(
    role='Research Assistant',
    goal='Gather information from multiple sources',
    backstory='Versatile researcher with access to various information sources',
    tools=[search_tool, web_tool, file_tool, code_tool],
    verbose=True
)

Custom Tool Development

python
from crewai_tools import BaseTool
from typing import Type
from pydantic import BaseModel, Field

class DatabaseQueryInput(BaseModel):
    query: str = Field(description="SQL query to execute")
    database: str = Field(description="Database name")

class DatabaseQueryTool(BaseTool):
    name: str = "Database Query Tool"
    description: str = "Execute SQL queries against specified databases"
    args_schema: Type[BaseModel] = DatabaseQueryInput

    def _run(self, query: str, database: str) -> str:
        # Implement database query logic
        try:
            # Connect to database and execute query
            result = execute_database_query(database, query)
            return f"Query executed successfully: {result}"
        except Exception as e:
            return f"Query failed: {str(e)}"

# Use custom tool
db_tool = DatabaseQueryTool()
database_agent = Agent(
    role='Database Analyst',
    goal='Query and analyze database information',
    backstory='Expert in database operations and SQL',
    tools=[db_tool],
    verbose=True
)

API Integration Tool

python
from crewai_tools import BaseTool
import requests

class APIIntegrationTool(BaseTool):
    name: str = "API Integration Tool"
    description: str = "Make HTTP requests to external APIs"

    def _run(self, endpoint: str, method: str = "GET", data: dict = None) -> str:
        try:
            if method.upper() == "GET":
                response = requests.get(endpoint)
            elif method.upper() == "POST":
                response = requests.post(endpoint, json=data)
            
            return response.json()
        except Exception as e:
            return f"API request failed: {str(e)}"

# Agent with API capabilities
api_agent = Agent(
    role='API Integration Specialist',
    goal='Interact with external services via APIs',
    backstory='Expert in API integration and data retrieval',
    tools=[APIIntegrationTool()],
    verbose=True
)

Memory and Context Management

Long-Term Memory

python
from crewai.memory import LongTermMemory
from crewai import Crew

# Crew with persistent memory
memory_crew = Crew(
    agents=[researcher, analyst],
    tasks=[research_task, analysis_task],
    memory=LongTermMemory(),
    verbose=2
)

# Memory persists across executions
result1 = memory_crew.kickoff(inputs={'topic': 'AI Ethics'})
result2 = memory_crew.kickoff(inputs={'topic': 'AI Regulation'})

Context Sharing

python
from crewai import Task, Agent

# Tasks that share context
context_task1 = Task(
    description="Research market trends",
    agent=researcher,
    expected_output="Market trend analysis"
)

context_task2 = Task(
    description="Analyze the market trends and provide recommendations",
    agent=analyst,
    expected_output="Strategic recommendations",
    context=[context_task1]  # Uses output from context_task1
)

Custom Memory Implementation

python
from crewai.memory.entity.entity_memory import EntityMemory
from crewai.memory.long_term.long_term_memory import LongTermMemory

class CustomMemory(LongTermMemory):
    def __init__(self, storage_path: str = "./custom_memory"):
        super().__init__(storage_path=storage_path)
        self.custom_entities = {}
    
    def save_entity(self, entity_name: str, entity_data: dict):
        self.custom_entities[entity_name] = entity_data
        # Implement custom storage logic
    
    def retrieve_entity(self, entity_name: str) -> dict:
        return self.custom_entities.get(entity_name, {})

# Use custom memory
custom_memory = CustomMemory("./project_memory")
crew_with_custom_memory = Crew(
    agents=[researcher, analyst],
    tasks=[research_task, analysis_task],
    memory=custom_memory
)

Advanced Features

Agent Delegation

python
from crewai import Agent

# Senior agent that can delegate
senior_researcher = Agent(
    role='Senior Research Director',
    goal='Oversee research projects and delegate tasks',
    backstory='Experienced research director with team management skills',
    allow_delegation=True,
    max_delegation=3,
    verbose=True
)

# Junior agents that can receive delegated tasks
junior_researcher1 = Agent(
    role='Junior Researcher - Technology',
    goal='Research technology trends and innovations',
    backstory='Specialized in technology research',
    allow_delegation=False
)

junior_researcher2 = Agent(
    role='Junior Researcher - Market Analysis',
    goal='Analyze market conditions and competitive landscape',
    backstory='Specialized in market research and analysis',
    allow_delegation=False
)

# Crew with delegation hierarchy
delegation_crew = Crew(
    agents=[senior_researcher, junior_researcher1, junior_researcher2],
    tasks=[complex_research_task],
    process=Process.hierarchical,
    verbose=2
)

Reasoning and Planning

python
from crewai import Agent

# Agent with enhanced reasoning capabilities
reasoning_agent = Agent(
    role='Strategic Planner',
    goal='Develop comprehensive strategies with detailed reasoning',
    backstory='Expert strategic planner with strong analytical skills',
    reasoning=True,  # Enable reasoning capabilities
    planning=True,   # Enable planning capabilities
    verbose=True,
    max_iter=10
)

# Task that requires complex reasoning
strategic_task = Task(
    description="""Develop a comprehensive 5-year strategic plan for AI adoption 
    in the healthcare industry. Consider:
    1. Current market conditions
    2. Regulatory environment
    3. Technology readiness
    4. Competitive landscape
    5. Implementation challenges
    
    Provide detailed reasoning for each recommendation.""",
    agent=reasoning_agent,
    expected_output="Comprehensive strategic plan with detailed reasoning"
)

Callback and Monitoring

python
from crewai import Crew, Agent, Task

def agent_step_callback(agent_output):
    print(f"Agent {agent_output.agent} completed step: {agent_output.step}")
    # Log to monitoring system
    log_agent_activity(agent_output)

def task_completion_callback(task_output):
    print(f"Task completed: {task_output.description}")
    # Send notification or update dashboard
    notify_task_completion(task_output)

def crew_step_callback(crew_output):
    print(f"Crew step completed: {crew_output}")
    # Update progress tracking
    update_progress(crew_output)

# Crew with comprehensive monitoring
monitored_crew = Crew(
    agents=[researcher, analyst, writer],
    tasks=[research_task, analysis_task, writing_task],
    step_callback=crew_step_callback,
    task_callback=task_completion_callback,
    verbose=2
)

# Agents with individual monitoring
monitored_agent = Agent(
    role='Monitored Researcher',
    goal='Conduct research with detailed monitoring',
    backstory='Researcher with comprehensive activity tracking',
    step_callback=agent_step_callback,
    verbose=True
)

Error Handling and Resilience

Retry Logic

python
from crewai import Task, Agent
import time

def retry_callback(attempt, error):
    print(f"Task failed on attempt {attempt}: {error}")
    time.sleep(2 ** attempt)  # Exponential backoff

resilient_task = Task(
    description="Perform web research with retry logic",
    agent=researcher,
    expected_output="Research findings",
    max_retries=3,
    retry_callback=retry_callback
)

Error Recovery

python
from crewai import Crew, Process

def error_handler(error, context):
    print(f"Error occurred: {error}")
    # Implement recovery logic
    if "rate_limit" in str(error).lower():
        time.sleep(60)  # Wait for rate limit reset
        return True  # Retry
    return False  # Don't retry

error_resilient_crew = Crew(
    agents=[researcher, analyst],
    tasks=[research_task, analysis_task],
    error_handler=error_handler,
    max_retries=3,
    verbose=2
)

Fallback Agents

python
from crewai import Agent, Task, Crew

# Primary agent
primary_researcher = Agent(
    role='Primary Researcher',
    goal='Conduct comprehensive research',
    backstory='Expert researcher with specialized tools',
    tools=[advanced_search_tool, database_tool]
)

# Fallback agent with basic capabilities
fallback_researcher = Agent(
    role='Backup Researcher',
    goal='Conduct basic research when primary agent fails',
    backstory='Reliable researcher with basic tools',
    tools=[basic_search_tool]
)

# Task with fallback logic
research_with_fallback = Task(
    description="Conduct research with fallback support",
    agent=primary_researcher,
    fallback_agent=fallback_researcher,
    expected_output="Research findings"
)

Performance Optimization

Parallel Execution

python
from crewai import Crew, Process
import asyncio

# Async crew execution
async def run_crew_async():
    crew = Crew(
        agents=[researcher1, researcher2, researcher3],
        tasks=[task1, task2, task3],
        process=Process.sequential,
        verbose=2
    )
    
    result = await crew.kickoff_async(inputs={'topic': 'AI Trends'})
    return result

# Run multiple crews in parallel
async def run_multiple_crews():
    crews = [create_crew(topic) for topic in ['AI', 'ML', 'NLP']]
    results = await asyncio.gather(*[crew.kickoff_async() for crew in crews])
    return results

Resource Management

python
from crewai import Crew
import threading

class ResourceManager:
    def __init__(self, max_concurrent_agents=5):
        self.semaphore = threading.Semaphore(max_concurrent_agents)
        self.active_agents = 0
    
    def acquire_agent_slot(self):
        self.semaphore.acquire()
        self.active_agents += 1
    
    def release_agent_slot(self):
        self.semaphore.release()
        self.active_agents -= 1

resource_manager = ResourceManager(max_concurrent_agents=3)

# Crew with resource management
resource_managed_crew = Crew(
    agents=[researcher, analyst, writer],
    tasks=[research_task, analysis_task, writing_task],
    resource_manager=resource_manager,
    verbose=2
)

Caching and Optimization

python
from crewai import Agent, Task
from functools import lru_cache

# Agent with caching capabilities
class CachedAgent(Agent):
    @lru_cache(maxsize=100)
    def cached_execution(self, task_description):
        return super().execute_task(task_description)

cached_researcher = CachedAgent(
    role='Cached Researcher',
    goal='Perform research with caching',
    backstory='Efficient researcher with caching capabilities'
)

# Task with caching
cached_task = Task(
    description="Research AI trends (cached)",
    agent=cached_researcher,
    expected_output="Cached research results",
    cache_results=True
)

Integration Patterns

Flask Web Application

python
from flask import Flask, request, jsonify
from crewai import Crew, Agent, Task

app = Flask(__name__)

# Initialize crew components
researcher = Agent(
    role='API Researcher',
    goal='Research topics via web API',
    backstory='Researcher accessible via web API'
)

@app.route('/research', methods=['POST'])
def research_endpoint():
    data = request.json
    topic = data.get('topic')
    
    # Create dynamic task
    research_task = Task(
        description=f"Research the topic: {topic}",
        agent=researcher,
        expected_output="Research findings"
    )
    
    # Execute crew
    crew = Crew(agents=[researcher], tasks=[research_task])
    result = crew.kickoff()
    
    return jsonify({'result': result})

if __name__ == '__main__':
    app.run(debug=True)

Celery Background Tasks

python
from celery import Celery
from crewai import Crew, Agent, Task

app = Celery('crewai_tasks')

@app.task
def execute_crew_task(topic, agents_config, tasks_config):
    # Reconstruct agents and tasks from config
    agents = [create_agent_from_config(config) for config in agents_config]
    tasks = [create_task_from_config(config) for config in tasks_config]
    
    # Execute crew
    crew = Crew(agents=agents, tasks=tasks)
    result = crew.kickoff(inputs={'topic': topic})
    
    return result

# Usage
result = execute_crew_task.delay(
    topic="AI in Healthcare",
    agents_config=[researcher_config, analyst_config],
    tasks_config=[research_config, analysis_config]
)

Database Integration

python
from sqlalchemy import create_engine, Column, Integer, String, Text, DateTime
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from crewai import Crew, Agent, Task
import datetime

Base = declarative_base()

class CrewExecution(Base):
    __tablename__ = 'crew_executions'
    
    id = Column(Integer, primary_key=True)
    crew_name = Column(String(100))
    input_data = Column(Text)
    output_data = Column(Text)
    execution_time = Column(DateTime, default=datetime.datetime.utcnow)
    status = Column(String(50))

# Database-integrated crew
class DatabaseCrew(Crew):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.engine = create_engine('sqlite:///crew_executions.db')
        Base.metadata.create_all(self.engine)
        Session = sessionmaker(bind=self.engine)
        self.session = Session()
    
    def kickoff(self, inputs=None):
        # Log execution start
        execution = CrewExecution(
            crew_name=self.__class__.__name__,
            input_data=str(inputs),
            status='running'
        )
        self.session.add(execution)
        self.session.commit()
        
        try:
            result = super().kickoff(inputs)
            execution.output_data = str(result)
            execution.status = 'completed'
        except Exception as e:
            execution.status = f'failed: {str(e)}'
            raise
        finally:
            self.session.commit()
        
        return result

Best Practices

Agent Design Principles

  • Single Responsibility: Each agent should have a clear, focused role
  • Clear Goals: Define specific, measurable objectives for each agent
  • Rich Backstories: Provide detailed context to improve agent behavior
  • Appropriate Tools: Equip agents with tools relevant to their roles
  • Delegation Strategy: Use delegation thoughtfully to avoid complexity

Task Organization

  • Clear Descriptions: Write detailed, unambiguous task descriptions
  • Expected Outputs: Specify exactly what output format is expected
  • Context Dependencies: Clearly define task dependencies and context sharing
  • Error Handling: Implement robust error handling and recovery mechanisms
  • Performance Monitoring: Track task execution and performance metrics

Crew Orchestration

  • Process Selection: Choose appropriate process type (sequential, hierarchical, parallel)
  • Memory Management: Use memory strategically for context retention
  • Resource Limits: Set appropriate limits for execution time and iterations
  • Monitoring: Implement comprehensive logging and monitoring
  • Testing: Thoroughly test crew behavior with various inputs

Performance Optimization

  • Agent Specialization: Create specialized agents for specific domains
  • Tool Optimization: Use efficient tools and minimize external API calls
  • Caching: Implement caching for frequently accessed data
  • Parallel Execution: Leverage parallel processing where appropriate
  • Resource Management: Monitor and manage computational resources

Troubleshooting

Common Issues

Agent Not Responding

python
# Debug agent configuration
agent = Agent(
    role='Debug Agent',
    goal='Test agent responsiveness',
    backstory='Agent for debugging purposes',
    verbose=True,  # Enable verbose output
    max_iter=1,    # Limit iterations for testing
    allow_delegation=False
)

# Test with simple task
test_task = Task(
    description="Say hello and confirm you are working",
    agent=agent,
    expected_output="Simple greeting message"
)

Memory Issues

python
# Clear memory if needed
crew.memory.clear()

# Check memory usage
print(f"Memory entities: {len(crew.memory.entities)}")
print(f"Memory size: {crew.memory.get_memory_size()}")

Tool Integration Problems

python
# Test tool functionality
tool = SerperDevTool()
try:
    result = tool._run("test query")
    print(f"Tool working: {result}")
except Exception as e:
    print(f"Tool error: {e}")

Performance Issues

python
# Monitor execution time
import time

start_time = time.time()
result = crew.kickoff()
execution_time = time.time() - start_time
print(f"Execution time: {execution_time} seconds")

# Profile memory usage
import tracemalloc

tracemalloc.start()
result = crew.kickoff()
current, peak = tracemalloc.get_traced_memory()
print(f"Current memory usage: {current / 1024 / 1024:.2f} MB")
print(f"Peak memory usage: {peak / 1024 / 1024:.2f} MB")

This comprehensive CrewAI cheat sheet provides everything needed to build sophisticated multi-agent AI systems. From basic setup to advanced orchestration patterns, use these examples and best practices to create powerful AI applications that leverage the collaborative power of multiple specialized agents.