CrewAI Guide 2025: Build Multi-Agent AI Systems

# Install

pip install crewai crewai-tools

# crew.py

import os
from crewai import Agent, Task, Crew, Process, LLM
from crewai_tools import SerperDevTool, WebsiteSearchTool

# Set API keys
os.environ["ANTHROPIC_API_KEY"] = "sk-ant-api03-..."
os.environ["SERPER_API_KEY"] = "your-serper-key"  # for web search

llm = LLM(model="claude-sonnet-4-6")
search_tool = SerperDevTool()
web_tool = WebsiteSearchTool()

# Define agents
researcher = Agent(
    role="Senior Research Analyst",
    goal="Find accurate, up-to-date information on the given topic",
    backstory="You are an expert researcher who excels at finding reliable sources.",
    tools=[search_tool, web_tool],
    llm=llm,
    verbose=True
)

writer = Agent(
    role="Technical Writer",
    goal="Write clear, engaging content based on research findings",
    backstory="You transform complex research into readable articles.",
    llm=llm,
    verbose=True
)

editor = Agent(
    role="Senior Editor",
    goal="Review content for accuracy, clarity, and completeness",
    backstory="You have 15 years of editing experience. You catch errors and improve flow.",
    llm=llm,
    verbose=True
)

# Define tasks
research_task = Task(
    description="Research the current state of AI coding assistants in 2025. Find the top 5 tools, their pricing, and key features.",
    expected_output="A structured research report with facts, sources, and key data points.",
    agent=researcher
)

write_task = Task(
    description="Write a 500-word article about AI coding assistants based on the research. Include a comparison table.",
    expected_output="A polished 500-word article with a markdown comparison table.",
    agent=writer,
    context=[research_task]  # receives researcher's output
)

edit_task = Task(
    description="Review and improve the article. Fix any inaccuracies, improve clarity, and ensure the table is formatted correctly.",
    expected_output="The final, edited article ready for publication.",
    agent=editor,
    context=[write_task]
)

# Assemble and run the crew
crew = Crew(
    agents=[researcher, writer, editor],
    tasks=[research_task, write_task, edit_task],
    process=Process.sequential,
    verbose=True
)

result = crew.kickoff()
print(result)