The Handbook
Eleven illustrated sections on who decides the next step at run time — writing code, prompts, context, loops, graphs, harnesses, evaluation and security. Twenty diagrams you can click through.
Read the handbook→A complete course on building systems that use AI — written for people who are new to software engineering. Three parts, about four hours, and you finish having built a working agent with an eval suite that scores it.
No account. No ads. Anonymous page counts only. MIT licensed.
Every program is a list of steps. The only question is who chooses the next one, and when.
You write the steps in advance. The computer follows them exactly, every time — fast, predictable, and blind to anything you did not think of.
You describe the goal and let the model choose the next step while the program is running. Flexible, surprising, and it has to be checked.
Almost every real system is a mixture of the two. Choosing the mixture is the whole job — and it is what you will practise here.
Each part asks a little more of you than the last. Start at the top.
Eleven illustrated sections on who decides the next step at run time — writing code, prompts, context, loops, graphs, harnesses, evaluation and security. Twenty diagrams you can click through.
Read the handbook→Four hands-on stages in this browser. Make a real model call, extend a rule-based till until it breaks, write your own prompt, then score it against twenty real cases and watch the number move.
Open the lab→Five more stages, on your own machine. The agent loop written by hand, tools that fail on purpose, a permission gate, a reviewer that cannot be skipped, and an email that tries to give your agent orders.
↗ Opens on GitHub. You will need a computer and a code editor.
Open the course↗The most valuable judgement in the field, and the cheapest to get wrong.
Not by reading its answers — by scoring it against cases and watching a number.
Tools break. The loop has to read the error and adapt, not crash.
Permission gates, mandatory review steps, and limits enforced in code.
Parts 1 and 2 assume no programming at all.
A full curriculum you can finish in an afternoon.
A 90-minute lesson plan, free to reuse and translate.
Yes. The whole course is MIT licensed and there is no account, no email capture and no advertising. The only thing measured is an anonymous page-view count, with no cookies and no profile of you. Parts 2 and 3 call a model, so you bring your own API key — the entire course costs a few cents of tokens.
Not for Parts 1 and 2. Part 3 assumes you can read and write basic TypeScript — functions, objects, a for loop, await. If you cannot yet, do Parts 1 and 2 and come back. A Python version of Part 3 is also kept in the repository.
DeepSeek or Anthropic's Claude, your choice. The code is written so that not one line of any exercise changes between them, which is itself one of the lessons.
Your key is held in the browser tab only and is erased when you close it. It is sent to the model provider and nowhere else. This site has no server, so there is nowhere for it to go — and the page-view counter never sees it.