best-of-Agent-Harnesses

Multi-agent and orchestration

Harnesses and patterns for multi-agent coordination and handoffs.

#ProjectStarsTierOSSDescription
1MetaGPT
multi-agentpython
68.9kcomplex✅The "AI software company" multi-agent framework: role-played PM, architect, and engineer agents turn a one-line requirement into specs, designs, and code along an SOP assembly line. The landmark of the genre; development pace has slowed in 2026.
2autogen
multi-agentpython
59.1kcomplex✅ CC-BYConversable agents and group chats; code execution and human-in-the-loop; Microsoft origin, AG2 ecosystem.
3crewAI
python
54.1kcomplex✅Role-based agents (roles, goals, backstories) in Crews; Flows add event-driven and hierarchical control for production.
4ChatDev
python
33.5kslightly complex✅Multi-agent software-company simulation (CEO, CTO, programmer, tester) built on chat chains with communicative dehallucination; ChatDev 2.0 continues the line. MetaGPT's conversational sibling.
5openai-agents-python
python
27.3kmostly simple✅Handoffs, guardrails, and multi-LLM routing; minimal surface so you own the loop.
6Microsoft Agent Framework
multi-agentworkflowpython
11.5kslightly complex✅Microsoft's convergence of AutoGen and Semantic Kernel: build, orchestrate, and deploy agents and multi-agent workflows in Python and .NET, with graph-based workflows and checkpointing — the designated successor harness for both lines.
7PraisonAI
multi-agentpython
8.2kmostly simple✅Autonomous multi-agent teams with a single entry point; emphasis on minimal config.
8AgentRL
trainingpython
302complex✅Multitask, multiturn RL for LLM agents; Ray-based scaling, rollout/actor workers—for teams that want to train agents, not just run them.