LangChain

Popular open-source framework for building LLM agents in code.

Free tier / Paid

Best for: Developers building custom agents

Ranked: #3 in Best agent builder

Last reviewed: 2026-10-18

LangChain alternatives

Other ranked picks best agent builder.

Open-source, self-hostable workflow automation with AI agent nodes; the most control for technical teams.

Build a custom ChatGPT assistant with your own instructions and files, no code needed.