Codebase 101 Free for public repos

It makes you understand how your codebase is built — after you build it.

You built something with AI. It works — you just don’t fully understand what you have. Codebase 101 reads your repo and walks you through it in a short guided tour: what each part is, why it matters, and what to learn next.

You’re not struggling to learn. You’re accepting what it’s giving you, straight into your brain.

No card required We never write to your code ~6 minutes, 8 short steps
The whole point

From “I built it but I don’t get it” to “I understand my own code.”

Vibe coding gets you a working app. It doesn’t get you the understanding — and without that, every bug is scary and every new feature is a guess. Codebase 101 closes exactly that gap.

Before
A repo you shipped but can’t read
  • You’re not sure which file does what
  • A small bug means an hour of poking around
  • New features feel risky, so you avoid them
  • You can’t explain how your own app works
After the tour
A repo you can name, part by part
  • You know the shape and every load-bearing part
  • A bug has an obvious place to look
  • You add features on purpose, not by luck
  • You have a clear next thing to learn
Meet the person this is for

Maya shipped an app with AI. Then she opened it and didn’t recognize it.

An illustrative portrait of the vibe coder Codebase 101 is built for — a real product situation, not a real customer.

Maya
A marketer who taught herself to build with AI. Over a few weekends she shipped PlantPal — a plant-care reminder app (Next.js + Supabase) that a handful of people actually use.
Illustrative persona
Before the tour
“It works — I just can’t explain it.”
  • Can’t say how the login actually works
  • Every bug is an hour of guessing
  • Scared to add a feature in case it breaks
After the tour
“Now I can name every part.”
  • The front door · how it knows it’s her · where her data lives
  • The reminder that runs on its own, without her
  • A first feature added on purpose, not by luck

Maya and PlantPal are the worked example the whole tour is built around — a realistic small app, so the tour’s craft is concrete. They are not a real customer, and no outcome here is a testimonial.

How it works

A short guided tour of your repo — about 8 steps, ~6 minutes.

Paste a public repo. Codebase 101 reads it and builds a tour of what you actually have. Each step shows a real part of your code, tells you why it matters, and points at what to learn next. It teaches at your pace — you don’t drive, you absorb.

STEP 1
The map of your repo
/ (the root)
STEP 2
The front door
app/page.tsx
STEP 3
How it knows it’s you
lib/supabase/auth.ts
STEP 4
Where your data lives
supabase/schema.sql
STEP 5
The part that runs without you
functions/water-reminders
STEP 6
The pieces on screen
components/PlantCard.tsx
STEP 7
The plumbing
app/api/plants/route.ts
STEP 8
Keeping it alive
.env · deploy
You’re in control of the pace — every step
AskStuck on a step? Ask — 5 free questions a day
Slow down · Just right · Speed upSet how fast it moves
Back · Next · SkipMove however you like
Who it’s for

Built for the vibe coder — and anyone facing code they didn’t write.

If you have a repo in front of you that you don’t fully understand, this is for you.

Who it’s for

The vibe coder

You built (or are building) something with AI and shipped it — but you don’t yet understand what you have. Codebase 101 makes that comprehension happen, so the thing you made becomes a thing you actually know.

Also

Joining a team

New engineer, new codebase, week one. Instead of reading 400 files cold, take the tour and get the shape and the load-bearing parts first.

Also

Onboarding yourself

Coming back to your own project after months away, or inheriting a side project. Get re-oriented fast, at your own pace.

Also

Reading unfamiliar code

A senior sizing up a repo they didn’t write — an acquisition, an audit, an open-source dependency. The tour gets you to the map in minutes.

Every scenario it serves — most impactful first

01Understand the code you just shipped — the killer use case — leads in the animated hero above and the vibe-coder card. Below: the next scenarios, each walked through the real tour routes — same flow, different repo.

02Onboard to an unfamiliar codebaseWeek one, a new repo — get the shape and the load-bearing parts instead of reading 400 files cold. Walk the tour →
03Find what’s fragile before you scaleAbout to add load — learn which parts are load-bearing, so you know where it’s fragile before you build on top. See the guided tour →
04Map a new framework to what you knowLearning a framework from a starter template — map its parts back to your existing mental model. See the repo shapes it reads →

Each mini-screen recreates the real screen it names in the live app — the repo-intake field, the tour’s code-and-explanation split, the dashboard, and the tour-complete screen. All five scenarios walk the same tour — only the repo differs. No proof numbers: the tour only ever tells you what it saw.

Also — grouped
  1. 05 Size up a repo you inheritedA consultant or senior inheriting a client’s repo gets to the few concepts they need to grok before shipping their first change. Walk the tour →
See what a tour looks like

One canonical example — and the repo shapes it adapts to.

Codebase 101 has no customer tours to show yet. This is the illustrative worked example the whole product is built around, plus the kinds of repo it reads.

PlantPal — the worked example, end to end A small Next.js + Supabase app, toured in 8 steps: the map · the front door · how it knows it’s you · where your data lives · the reminder that runs without you · the pieces on screen · the plumbing · keeping it alive. Fully clickable. Open the tour →

A web app

A Next.js / React front end with a Supabase or Postgres backend — the classic vibe-coded SaaS or side project.

An API or service

A Python / Node service — routes, a data layer, background jobs, the deploy that keeps it up.

A script or tool

A smaller repo — a CLI, a bot, an automation — where the tour is shorter but the shape still gets named.

These archetypes show the kinds of repo the tour reads; they are illustrative. A real tour is generated by the engine from your repo — it is never a pre-written script, and it renders only what it actually saw.

Your dashboard

Pick up where you left off — and teach it your way.

The tour is the lesson; the dashboard is your control room. Three jobs, one place.

Resume

Know your current step and jump straight back in. Leave any time; come back exactly where you were.

The whole picture

See the full path at a glance — what’s done, where you are, and what’s left — so you always know how far you’ve come.

How it teaches you

Four dials, so the tour meets you where you are. Change any one and it takes effect on your next step.

Pace
Slow down · Just right · Speed up
Density
Just the gist · Balanced · Go deep
Explain it like…
New to code · Some code · Ship regularly
Get better at
Reading code · Debugging · Adding features
Why a tour, not a chat

It teaches you your codebase. It doesn’t wait for questions.

You can already ask an AI about your code. The problem is you don’t know what to ask — that’s the whole reason you don’t understand it yet. A guided tour decides the path for you and walks it.

Asking a chatbot

Great when you already know the question
  • You have to know what to ask
  • Answers are scattered, one at a time
  • No path — you might miss the load-bearing parts
  • You’re still driving; it’s still work

The Codebase 101 tour

Great when you don’t know where to start
  • It picks the path through your repo
  • One coherent walk, in order, that builds
  • It covers the parts that actually matter
  • You absorb; it does the driving

Need to interrogate a specific line? That’s what Claude Code is for. Codebase 101 is the part that gets you to understanding in the first place.

The fine print, in plain English

Read-only, no card, honest about what it saw.

Free for public repos
Paste a public repo and go — no card required to take the tour.
We never write to your code
Codebase 101 reads your repo. It never opens a PR, never pushes, never edits a file.
It only tells you what it saw
Every step points at a real file in your repo. If it can’t read something, it says so — no invented tour.
What this page is honest about

Codebase 101 is a real, early build. Here’s the honest grain.

What’s real
The app — repo intake, the guided tour, your dashboard, and tour-complete are live and walkable end to end.
What’s illustrative
Maya, PlantPal, and the example tours are a realistic worked example of a small app — not a customer, not a testimonial, no invented metric stands in as proof.
What’s not built yet
The engine that reads a real repo and generates the tour — every tour today is the worked example (no repo is read, nothing is written). Progress and settings show live but aren’t saved across sessions yet.
Codebase 101

Paste a repo. In six minutes, understand it.

It works either way — but understanding what you built changes how you build next.

Codebase 101 · Free for public repos

Understand the code you just built.

A short guided tour of your repo — what each part is, why it matters, and what to learn next. It teaches; you absorb.