Free course · for engineers who already use coding agents
From using agents to engineering them.
You already ship code with Claude Code, Codex or Cursor. This course gives you the discipline behind it: context engineering, harness engineering, loop engineering, orchestration and evals, in clear terms and with runnable examples. Every code sample is a small harness written in plain Python and was executed with the real interpreter when this page was built, so every output you see is real.
- 8 lessons
- 3 practice tools
- 33 runnable samples
- 105 drill items
- 95 flashcards
The path
read in order, or jump to what you need
Context and harness
How to use it
Answer before you look
Every prediction hides the output until you commit. Wrong answers teach more than right ones.
Every output is real
Each sample ran with Python 3.14.8 when the course was built. Run shows what it printed.
Drill until it sticks
Labs, the error decoder and spaced flashcards turn the lessons into habits.
The map
Four disciplines, one stack
The vocabulary moved fast. In February 2026 Andrej Karpathy proposed agentic engineering for professional work where you orchestrate agents instead of writing most code yourself. Under that umbrella, practitioners now use three more precise terms. They nest:
The three mental models
Everything here comes back to these
Three rules that explain agentic engineering
- Agent = model + harness. The same model performs very differently depending on its instructions, tools, permissions and context. Most reliability comes from the system around the model.
- Enforce, don't request. A rule in a prompt is a request the model may forget. A rule in a hook, a schema, a test or a permission is a guarantee.
- The context window is a budget. Every token competes for attention and money. Load what the step needs, when it needs it, and nothing else.
Short on time
The 90-minute route
Vocabulary and the loop
Context and harness
Loop engineering
Goals, checks, stop conditions: page 7. 15 minutes.Lab + cards
L1 drills, then 20 flashcards. 20 minutes.
A course your coding agent can read too
Every page has a Markdown version
Point your agent at a page with .md, at llms.txt, or at the docs MCP server, and it reads the same lessons, labs and answers you do.
Your data
Progress is saved in this browser as you go. Coming from the standalone course? Import its progress file.