AppBuildersPH Hackathon 2026 · Theme: Local AI

PumpLocal

When the power or the internet stops, the work doesn't.

An offline assistant for a small Filipino gas station. It reads pump totalizer photos and receipts, checks fuel and cash at shift end, and answers staff questions in Tagalog or English. It runs on a MacBook Air with Wi-Fi off.

The app runs locally on the station's computer. This page is the showcase. There is no hosted version to log into. The screenshots, slides and demo video below show what it does.
View the code on GitHub Open the slides
~2 s
Apple Vision OCR reads a photo on-device
0
internet needed to record and check a shift
2.57 L
unaccounted fuel found on the demo pump check
₱50
cash short found on the demo closing slip

The problem

JCB Gas Station is in Sto. Niño, South Cotabato. In the province, brownouts and weak internet are part of the week, and cloud apps stop working when either one hits.

🔌

Brownouts

When the power goes out, the router goes with it. Cloud tools that need a connection can't record or check anything.

📶

Weak internet

Even with power, the signal drops. A station app that needs the cloud stops at the moment the shift needs to be closed.

⚠️

Gaps go unchecked

Fuel that left the pump without a recorded sale, and cash that doesn't match, slip through when nobody can run the check.

How it works

Photo → numbers → fuel & cash check → ask. The models read and explain. Plain code does every peso and liter of math.

  1. Litrato

    📷 Photo

    Snap the pump's totalizer screen, a meter, a receipt or the shift closing slip.

  2. Numbers

    🔢 Numbers

    Apple Vision OCR reads the digits on the Mac in about 2 seconds. Code matches each number to its label. Staff can fix anything before saving.

  3. Fuel & cash check

    ✅ Check

    Code compares pump totals (closing − opening) with recorded sales, and expected cash with counted cash. Gaps over the tolerance turn red.

  4. Magtanong

    💬 Ask

    Staff ask in Tagalog or English, like “May kulang ba sa diesel?” Gemma 3 4B answers from the computed numbers only.

Apple Vision OCR (on-device) Gemma 3 4B via Ollama SQLite Python · Decimal math Works with Wi-Fi off Syncs when the internet is back
2.57 L unaccounted

Premium 3: the pump says 416.07 L dispensed, recorded sales are 413.5 L (0.62%, over the 0.5% tolerance). The pump readings come from real photos; the sales are sample data.

Real pump photos · sample sales
₱50.00 short

The shift closing slip is read and checked against the shift: expected cash ₱39,219.55, declared ₱39,169.55. Kulang ang pera sa kaha ng ₱50.00.

Demo closing slip

Demo video

A short walkthrough of PumpLocal running on the MacBook Air with Wi-Fi off.

Demo video coming soonThe walkthrough will be embedded here.

Screenshots

The app's screens, captured from the latest build. Tap any image to see it full size.

Pump tab showing UNACCOUNTED FUEL: 2.57 L (0.62%) on Premium 3
Pump check: unaccounted fuelPremium 3 opening and closing totalizers vs. recorded sales.
Cash tab showing SHORT ₱50.00 with the expected-cash breakdown
Cash check: ₱50 shortLine-by-line expected cash, computed in code.
Photo tab after reading a meter photo
Photo → numbersA meter photo filled into an editable form.
Pump tab full result
Pump resultPesos and liters, opening to closing.
Scanned shift closing slip review table
Closing slip scanEvery value read, new vs. already saved.
Cash tab full result
Cash resultShort/over with the pump-vs-sales summary.
Ask tab answering a Tagalog question
Ask in Tagalog“May kulang ba?” answered with the real numbers.
Shift tab with recorded sales
ShiftThe shift's sales, discounts and credit.
More screens: each tab on desktop
Photo tab
PhotoLitrato ng metro o resibo.
Shift / sales tab
ShiftBenta ngayong shift.
Pump tab
PumpMetro ng pump.
Cash tab
CashBilang ng pera.
Ask tab
AskMagtanong.

Slides

The five-slide pitch deck. Open the full slides (use ← → or click to move, F for fullscreen).

Slide 11 · The problem Slide 22 · Why local AI? Slide 33 · At the station Slide 44 · What's next Slide 55 · Wi-Fi off

Station setup

Small, cheap and able to ride out a brownout. Nothing in the shift check depends on the internet.

Proposed

🖥️ Mac mini + Wi-Fi router on one small UPS

The Mac mini runs PumpLocal and the local models. Staff phones can reach it over the station's own Wi-Fi, so the network stays up even when the internet is down.

  • One small UPS keeps both running through a brownout
  • Records queue locally and sync when the internet is back
Also works

💻 Laptop on battery + power bank for the router

A MacBook Air runs on its own battery, and a power bank keeps the router alive.

  • No extra hardware to buy
  • Same app, same offline checks

Honest notes

What's real, what's sample data, and who (or what) did the work.

Data

  • The Premium 3 totalizer readings come from real pump photos from JCB Gas Station.
  • The sales are sample data, so the 2.57 L gap shows how the check works. It is not a real loss at the station.
  • The closing slip and other sample meters and receipts are demo material.
  • The screenshots on this page were captured on a Linux test machine, where Apple Vision can't run: OCR text recorded from the sample photos was replayed, and AI wording was in template (mock) mode. All the math shown is the app's real code.

AI disclosures

  • Grok Bot (an AI coding assistant) built PumpLocal, writing the code, tests and docs under Johnny's direction.
  • Claude was used only to install Ollama and for Mac cleanup. It wrote no PumpLocal code.
  • The demo video is voiced with ElevenLabs.
  • The full timeline, problems hit and AI usage are in BUILD_LOG.md.