CrewAI

Lightweight framework from OpenAI for multi-agent workflows with handoffs, guardrails, tracing and MCP tools.

Framework for document-centric agents and RAG, with parsing and indexing tools.

Low-level orchestration framework for building resilient, stateful agents as graphs.

Framework and runtime for building, running and managing multi-agent systems.

Hugging Face's barebones library for agents that think and act by writing code.

Google's code-first toolkit for building, evaluating and deploying agents.