magnus919_agent-skills/crewai/references/crew-patterns.md

CrewAI Crew Patterns

Sequential Process

Tasks run in order. Each task receives the output of the previous task as context.

from crewai import Crew, Process

crew = Crew(
    agents=[researcher, writer, reviewer],
    tasks=[research_task, write_task, review_task],
    process=Process.sequential,
    verbose=True,
)
result = crew.kickoff()

Hierarchical Process

A manager agent assigns tasks and validates results. Requires manager_llm.

from crewai import Crew, Process
from langchain_openai import ChatOpenAI

crew = Crew(
    agents=[researcher, writer, reviewer],
    tasks=[research_task, write_task, review_task],
    process=Process.hierarchical,
    manager_llm=ChatOpenAI(model="gpt-4"),  # Required!
    verbose=True,
)

Crew Parameters

Parameter	Description
agents	List of agents in the crew
tasks	List of tasks to execute
process	Process.sequential or Process.hierarchical
manager_llm	Required for hierarchical. LLM for the manager agent
verbose	Print detailed execution logs
memory	Enable cross-agent memory
cache	Enable tool result caching
planning	Enable planning step before execution
max_rpm	Rate limit across the crew

Key Gotchas

• Hierarchical without manager_llm fails silently. The crew appears to run but produces no output.
• Sequential with more than 4-5 agents can produce very long completion times (each agent waits for the previous).
• Crew-level `memory=True enables agents to remember context across tasks.
• Tool caching (cache=True) prevents repeated API calls for the same input.
• crew.kickoff() is synchronous by default. For async, check the async API.