The integration of LangChain primitives directly into n8n's visual canvas allows software engineers to build autonomous agents capable of dynamic reasoning, tool invocation, and multi-turn state retention.
1. ReAct (Reason + Act) Loop
At the core of an n8n AI Agent is the ReAct paradigm:
- Thought: The agent evaluates the user prompt and determines the necessary missing data.
- Action: The agent executes a connected tool node (e.g. HTTP Request, Vector Search, SQL Query).
- Observation: The tool returns raw JSON back to the agent's context window.
- Final Synthesis: The agent crafts a coherent answer or initiates secondary tool operations.