Tutorial: Building a LangGraph-Powered Streaming Chat Agent with Swappable AI Models

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Developer Néstor Daza has published the fourth installment of his series on building Claudius, a Claude-based chatbot powered by AWS Bedrock. The article explains how the chat engine is structured as a small state machine using LangGraph, consisting of three nodes: a context loader, the AI agent, and a tools executor. A conditional edge allows the agent to loop through tool calls — such as web searches — until it is ready to return a final natural language response. A key design choice is that the AI model is not fixed at compile time; instead, it is selected per run via LangGraph's configurable channel, allowing users to switch models mid-conversation without losing context. The next article in the series will cover conversation persistence, usage metering, and write-operation safeguards.

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