promptdojo_
what is this?

you live in cursor now. read what it wrote.

promptdojo is the python school for the new job — directing ai agents, reading what they wrote, catching what they got wrong. it's not a syntax course. it's a school for editing the model.

31 chapters·833 steps·8–15h·MIT·last commit 2026-05-14
the wedge

every course teaches you what python is.
you need to know what it isn't.

the old job

memorize syntax, write loops by hand, build a calculator from scratch.

the new job

read what the model wrote, find where it lied, ship the fix in five lines.

the gap

you can vibe-code a hundred features without learning python. then one bug ships and you can't read the traceback.

the curriculum

31 chapters. 833 runnable steps. zero install.

phase 00
ch 00

before you build

for anyone whose job got eaten by ai. what an llm is, how to talk to one, and what this course is going to ask of you.

phase 01
ch 01–07

foundations

variables, functions, lists, dicts, loops, conditionals, tracebacks, mutation

phase 02
ch 08–12

real python

modules, error handling, files & i/o, classes, http

phase 03
ch 13–16

llm apis

calling models, structured output, mcp, agent loops

phase 04
ch 17–24

shipping discipline

git, secrets, prompting, traces, evals, retrieval, tradeoffs

phase 05
ch 25

capstone

ship a working cli agent in 12 steps. ~100 lines of python.

phase 06
ch 26–30

applied builds

agent harnesses, ai image gen, ai video gen, programmatic design, harness engineering

the loop

read. run. fix. repeat 833 times.

01

read

every step shows you a small piece of code or concept. plain english explanation, no walls of theory.

02

run

python runs in your browser via pyodide. no install, no venv. the editor is right there. click run.

03

fix

most steps end with a buggy snippet. you fix it. you run it. you move on. you never write a fizzbuzz.

why this, not codecademy

the old way assumes you'll write the code.
you won't.

old waypromptdojo
watch a videoread 100 words and run code
write fizzbuzz from scratchfix the model's broken fizzbuzz in three lines
learn syntax for two weekslearn the syntax you trip on, ignore the rest
hello-world your way to a jobship a cli agent by chapter 25
sign up, lose streak, pay $19/mofree preview on the web, the school lives in the app
who built it

i'm josh. ai consultant. i ship python with cursor and claude every day for client work. i wrote this because every other course felt like a museum tour and i wanted the workshop floor.

i ship to this site weekly. follow the build at @TFisPython.

why a paid app?

the web is the preview. the app is the school.

honest update: this site used to promise “free forever, no paid tier, ever.” the web preview part stays true forever. but the native app is coming after, and that one costs money. i'd rather tell you the trade than hide it.

the web launches now. the app drops once enough of you are in. you can join early access to lock in the founders rate before iOS ships.

why now

i'm one person. i ship to this site weekly between client work and i can't keep doing that on weekends alone. charging for the app pays for the next chapter, the next revision, the ai tutor compute. no charge, no school.

why a paid tier

apple and google take 15-30% of every sale. the ai tutor calls claude on every failed attempt and that's metered tokens. the apple developer fee is $99/yr just to exist on the store. this isn't a business — it's a school that has to cover its own bill.

what stays free

the web preview: three full chapters — variables, llm apis, agent loops. read every step, no signup, no time limit. about 30 minutes of content. enough to know if the school is for you before you pay for it. the preview is the preview, not a trial. it doesn't expire.

the app: 31 chapters, the full python ide, ai tutor on every failed attempt, cloud sync, offline mode. $9.99/mo · $59/yr · $129 lifetime (first 100 buyers).

faq

quick answers.

last revised 2026-05-06

is the web preview really free?

yes. three full chapters, no signup, no time limit. about 30 minutes of content. it's a preview, not a trial — it doesn't expire.

what does the app cost?

$9.99/mo, $59/yr, or $129 lifetime for the first 100 buyers. then lifetime jumps to $199. apple and google take 15-30% of every sale. the rest funds the build.

why isn't it on udemy / coursera / boot.dev?

because i wanted it to look how i wanted, run in the browser, and never gate-keep behind a streak.

do i need python experience?

no. chapter 01 starts at variables. if you've used cursor or claude to write code, you know enough to begin.

do i have to log in?

no. progress saves to your browser. login only syncs across devices — same email anywhere else, same dojo. no list, no upsell.

how long does it take?

most steps are 30 seconds. realistically: 8–15 hours total spread over a few weeks.

how often is it updated?

commits land most weeks. content gets revised when models change shape — the agent-loop chapter looks different in 2026 than it did in 2025. follow the build at @TFisPython.

what if i find a bug?

open an issue or a pr at github.com/xernst/promptdojo. or dm me on x.

stop reading. start fixing.

chapter 01 is variables. chapter 25 is a working cli agent. the only step that matters is the next one.