CrewAI

CrewAI is an open-source Python framework for building multi-agent AI systems where each agent has a role, tools and goals and they collaborate on a task, used by developers and AI teams automating research, reporting and back-office processes. It supports sequential and hierarchical workflows, tool calling, memory and human-in-the-loop checks, plus a hosted enterprise platform for deployment and monitoring. The framework itself is free and open source, with paid managed offerings.