Patchbook: Agents are just loops

Short, simple chapters that serve as a conceptual upgrade for software engineers.

The central thesis is simple: you do not need an agent framework to have an agent. An agent is four plain parts: an HTTP call, an array, some JSON, and a loop. This book follows that loop as it learns to read, to act, and to remember. Every chapter ends with a prompt you can paste into your own chat, so you can watch each idea happen. By the last page, the parts add up to something familiar: the coding agent you use every day.

In development. Chapters will appear below as they are written.

Let us begin with Chapter 0: Introduction.

• Chapter 0: IntroductionWhat this book is, what you will learn, and who it is for.
• Chapter 1: Why agents matterThe case for knowing the machine: what that buys you, and the shift that turns human language into a programming language.
• Chapter 2: The simplest agentThe loop every agent is built from: input, memory, API call, response, display.
• Chapter 3: Knowledge in the loopRAG and attachments: two ways external knowledge enters the loop.
• Chapter 4: The first way to actFrom JSON output to the tool contract: how a model learns to act.
• Chapter 5: The toolboxRead tools, the surgical write idiom, and bash: the filesystem toolbox.
• Chapter 6: MemoryCompaction and sessions: how the loop manages its own memory, and the machine, assembled.