How Koda works
From the device on the counter to the pencil in your child's hand.
This page walks through everything: setup, a typical session, what Koda does when your child is stuck, the adventure tracks, exam mode, and what shows up in your inbox on Friday.
Three things, in a loop.
No screen time. No tablet propped against the cereal box. The child writes; the camera watches; the tutor asks.
- 01Worksheet on the table.
Your child opens any paper worksheet — a homework page, a printable, the back of an envelope. The overhead camera looks down at the paper.
- 02Koda watches and asks.
Koda reads what your child wrote. When the work shows a slip, Koda asks a small question. When it's clean, Koda says so.
- 03Your child writes the next step.
The pencil keeps moving. Koda doesn't give the answer. The work stays in the notebook — at the end, it's still your child's.
5 minutes, plug in, get to work.
Plug the device into a TV or monitor. Place the overhead camera so it sees the worksheet. Place the front camera so it sees your child. Open Koda. Add a profile. Take three photos for face recognition (optional). Done.
- STEP 1Plug it in (or run it on your Mac)
Koda bundle: device → TV or monitor → power. Or BYOD: install Koda on a recent Mac with Apple Silicon and connect it to a screen. Either way, nothing else needs to be installed on your laptop or your child's tablet.
- STEP 2Mount the cameras
Overhead camera looks down at the worksheet. Front camera sits on top of the screen. Both are USB; both are off when there's no session. The bundle ships with two cameras; if you bring your own setup, any two USB webcams from the verified list work.
- STEP 3Add a profile
Tap the empty avatar tile. Type your child's name. Pick a base avatar. Optionally take three photos so Koda can greet your child by name. Frames stay on the device.
Why a dedicated device and not a tablet, and why on-device instead of the cloud? The architecture note — why we run on-device instead of in the cloud — walks through the decision and what we accept by going local. (For the same reason we offer BYOD: a recent Mac with Apple Silicon already has the silicon Koda needs.)
Sit down, open the worksheet, get to work.
Koda is ambient. Your child doesn't open an app — they sit down at the desk. The face camera picks up who it is. The voice asks if they want to start. The pencil hits the paper.
The hint ladder. Koda never gives the answer.
When your child slows down or writes something that doesn't add up, Koda climbs a ladder of nudges — each one less subtle than the last. The pencil stays in your child's hand.
- 01Notice
Koda points at the part of the worksheet that has the slip. "Look at the ones column."
- 02Ask
Koda asks a question that hands back the next move. "What does 12 minus 7 give you?"
- 03Show a similar one
Koda walks through a smaller, similar problem out loud. The current problem stays untouched.
- 04Show a video
If your child is still stuck, Koda offers a short explainer video — drawing on five teaching angles, with whichever has rendered for that topic available to pick. Your child picks.
Koda climbs the ladder slowly. Most slips get caught at step 1 or 2. Your child gets to feel the click of working it out — not the deflation of being told. The longer note — how Koda decides when to interrupt — walks through the default-silent rule, the three triggers that break it, and the escalation rule between rungs.
20 minutes of quiet. Then a review.
When your child takes an exam, Koda shuts up. No hints, no nudges, no cheerful interjections. After the timer, Koda walks back through every wrong answer with your child.
A long arc, not a streak.
Three worlds — Space, Ocean, Forest — five levels each. Each level ends in a boss problem that pulls together what the level taught. No streak counter ships. Effort earns XP, not just correct answers.
A digest, written like a friend would write it.
What your child worked on this week, what tripped them up, what's coming next. Specific numbers. No leaderboards. No comparisons to other kids.
Notes on the parts of this we've thought about hardest.
- How Koda decides when to interrupt →
The default-silent rule, the three triggers, and the four-rung hint ladder.
- We don't trust the LLM to grade arithmetic →
Why an open-source symbolic-algebra library checks every math answer instead of the language model.
- Paper-first: why our tutor watches a worksheet instead of a screen →
The cognitive-science argument for hand-on-paper, with citations.