What is the best open-source framework for building AI agents in 2026?

The best open-source framework for building AI agents in 2026 depends on the use case, with popular options including LangChain/LangGraph, Google ADK, DeepAgents, CrewAI, AutoGen, and AG2.

What is the best open-source framework for building AI agents in 2026? There are multiple of them but it depends on your use-case. I am personally using LangChain/LangGraph, Google ADK, and DeepAgents but they can be complex for some. Most people use CrewAI, AutoGen, and AG2. I think n8n is not open-source but I never used it and can be wrong.