OpenAI and Anthropic have both placed their coding CLI clients on GitHub, letting developers see the code that powers their AI‑assisted programming tools. A recent post by Bolin explains the core "agent loop" that coordinates user input, model responses, and tool calls. The loop repeatedly builds a prompt, sends it to the model, and either returns a final answer or executes a requested tool before querying the model again. The initial prompt is assembled from distinct components—system, developer, user, and assistant—each with a specific role, and includes instructions, tool definitions, sandbox settings, environment context, and the user’s message.
Read more →