ADK Java ReAct Implementation — Reasoning + Acting Loop

Why it matters

ReAct is the most common agent pattern. Understanding ADK Java's implementation enables real deployment.

The architecture

LlmAgent with tools: reasoning happens via prompt; actions via tool calls.

Iteration: default max iterations; agent terminates when it outputs no tool call.

How it works end to end

Structured function calling: Gemini and other modern LLMs handle tool calls natively. No text parsing required.

Termination: LLM outputs final response without tool call = done.

Loop safety: max iterations config.