This visualization documents a three-layer IoT architecture that connects a Raspberry Pi Pico W to cloud-based large language models, demonstrating a secure proxy solution for HTTP-only microcontrollers. The practice shows a flow diagram of data passing from the Pico W’s MicroPython sensor logic and a local mini-RAG knowledge base, through a FastAPI proxy running on a laptop, to a Google Apps Script backend that holds the API key and calls OpenAI’s GPT-4o-mini. The example uses JSON payloads for data exchange, and renders the architecture as WebGL with a Vue-based interface, highlighting the responsibilities of each layer in a table format.