CrewAI

CrewAI is a framework for building multi-agent AI systems that work like coordinated teams. Instead of a single AI agent trying to do everything, CrewAI lets developers define a crew of specialized agents — each with a role, backstory, and set of tools — that collaborate to accomplish complex tasks. The core metaphor is organizational: a Researcher agent searches for information, a Writer agent composes content, an Analyst agent interprets data, and a Manager agent coordinates the crew and delegates tasks. Each agent is powered by an LLM and can use any tool: web search, code execution, file operations, database queries, and custom APIs. CrewAI's Sequential and Hierarchical process modes control how agents collaborate. In Sequential mode, tasks flow from agent to agent like an assembly line. In Hierarchical mode, a manager agent dynamically assigns and reviews tasks based on their complexity and the crew's progress. The framework is model-agnostic — it works with GPT-4, Claude, Gemini, Mistral, LLaMA, and any OpenAI-compatible API. It integrates with LangChain tools, allowing access to a vast ecosystem of pre-built agent capabilities. CrewAI has become one of the most popular agent frameworks in the AI developer community, with thousands of production deployments for use cases ranging from automated research pipelines to customer support workflows to software development automation.