Last time we talked about the Think-Act-Observe loop — the skeleton of an AI coding assistant. A skeleton can’t work on its own; it needs muscle. In Claude Code, that muscle is tools. Without tools, the loop loses the Act between Think and Observe and degenerates into plain Q&A. With tools, the model can touch the real world: read your code, change your configs, run your tests.
If you dig through the Claude Code source, you will discover a counterintuitive fact: The core of the entire program is a while loop. Not a complex state machine, not an elaborate pipeline, not distributed coordination — just a plain while loop that does three things over and over: let the model think, let the model act, feed the results back. 1 2 3 4 5 6 7 8 9 while (user hasn't quit) { thinking = callLLM(conversation history + tool definitions) if (thinking.wants to call a tool) { result = executeTool(thinking.toolCall) conversationHistory.push(result) } else { output(thinking.reply) } } That’s it? The entire secret of an AI coding assistant lives in this loop?
