Term
ReAct pattern
Reasoning + Acting — a prompting pattern from a 2022 paper where the LLM interleaves chain-of-thought with explicit tool calls. The pattern that most modern coding agents implement under the hood.
Background
In ReAct, each step has a thought (private reasoning), an action (tool call), and an observation (tool result). The loop continues until the model emits a final answer. ReAct is the conceptual ancestor of every plan/act, code-act, and agentic loop in 2026 coding tools.