from crewai import Crew, Agent, Task

extract_agent = Agent(name='Extract', ... )
join_agent = Agent(name='Join', ... )
quality_agent = Agent(name='Quality', ... )

crew = Crew(
    agents=[extract_agent, join_agent, quality_agent],
    tasks=[
        Task(agent=extract_agent, ...),
        Task(agent=join_agent, ...),
        Task(agent=quality_agent, ...)
    ]
)
crew.run()