How an LLM Request and Response Cycle Works: A Full Walkthrough

A single LLM prompt passes through client app, API gateway, tokenization, transformer forward pass, and streaming pipeline before a response appears. The process involves building a JSON request, tokenizing input into numeric IDs, predicting one token at a time, and streaming tokens back as text. This explains the word-by-word appearance of responses and the steps between pressing Enter and seeing output.