CrewAI

Handoffs

One agent passes the conversation to another agent, which takes over.

Not shown in the docs.

Subagents / agents as tools

A main agent calls other agents like tools and gets their result back, each with its own context.

Graph or workflow

You define steps and edges (or a workflow), and the framework runs agents and functions through them.

Group chat / crew

Several agents with roles work together on a task, coordinated by a manager or a selection rule.

Human in the loop

The run pauses for a person to approve, edit or answer before it continues.