What is ReAct (Reasoning + Acting)?
TL;DR
A framework that has LLMs alternate between reasoning and acting (tool use) to solve complex tasks.
ReAct (Reasoning + Acting): Definition & Explanation
ReAct (Reasoning + Acting) is a framework that enables LLMs to alternate between reasoning (thinking) and acting (executing external tools or API calls). While traditional LLMs were limited to reasoning alone, ReAct follows a cycle of 'think → act → observe → think,' allowing the model to gather external information and solve problems step by step. For example, it can answer complex questions while performing web searches or database queries along the way. ReAct agents are widely implemented in frameworks such as LangChain and LlamaIndex.