# What is ReAct Prompting? Definition & Technical Mechanics

> **Source:** [SPIDITS AI AI Glossary](https://spidits.com/ai-glossary)  
> **Category:** Agentic Workflows  
> **Canonical Citation:** [https://spidits.com/ai-glossary/react-prompting](https://spidits.com/ai-glossary/react-prompting)

## Definition
ReAct (Reasoning and Acting) is a prompt architecture that enables autonomous AI agents to interleave verbal reasoning traces (Thought) with task execution actions (Action and Observation).

## Architectural Mechanics & Deep Dive
ReAct (Reasoning + Acting) is a foundational prompt architecture for autonomous AI agents that tightly couples verbal reasoning traces with tool execution. By forcing language models to alternate between explicit internal thought, tool action invocation, and environmental observation parsing, ReAct dramatically improves problem-solving accuracy and reduces hallucinations.

## Industry Applications & Real-World Use Cases
Autonomous tool execution, web search retrieval, API interaction, and multi-step problem solving

## Frequently Asked Questions

### What are the three steps in a ReAct loop?
The three steps are Thought (internal reasoning), Action (executing a tool or API call), and Observation (reading the result returned by the environment).

### Why is ReAct effective for LLM agents?
It reduces hallucinations by grounding the agent reasoning steps in external real-world observations and API responses.

## Related Terminology
- [agentic-ai](https://spidits.com/ai-glossary/agentic-ai)
- [function-calling](https://spidits.com/ai-glossary/function-calling)
- [guardrails](https://spidits.com/ai-glossary/guardrails)

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*From the SPIDITS AI Knowledge Base (336+ terms indexed). Explore full technical definitions: [https://spidits.com/ai-glossary](https://spidits.com/ai-glossary)*