01 · the barrier
The data was never trustworthy
In Walmart's blockchain mango pilot, suppliers typed the data in by hand, so it could be false.
Every reading is signed inside a chip, at the sensor.
Live simulation · real cryptography
Prove how your produce was kept, from farm to buyer.
A rugged, reusable Tag rides on every pallet. It signs each reading inside a tamper-proof chip, keeps recording when the signal drops, and lets anyone check the whole trip with one scan.
No login. Runs in your browser. Readings are simulated; the signing and checking are real.
Built for Smart India Hackathon 2026,
problem statement SIH26232.
T
T.R.A.C.T. verify
Scanned from the crate label
✓Verified
Every reading is signed by this Tag's chip and none has been changed.
- Cargo
- Alphonso mangoes
- Route
- Ratnagiri → Dubai
- Fruit held at
- 12–14 °C, 61 h
- Box opened
- Never
- Readings edited
- 0 of 366
- Freshness
- 92 / 100
Made at the sensor
Signed in a chip
* our own 3D CAD model
What is this?
A sealed box that rides with the fruit and keeps an honest diary of the journey.
- 1
It watches
Temperature, ripening gas, bumps, and whether the box was opened, every 10 minutes, even with no signal.
- 2
It locks each entry
A chip inside signs every reading. Nobody, including us, can change one afterwards without it showing.
- 3
Anyone can check
A buyer scans the QR code on the crate and sees a green tick or a red mark, in seconds, on any phone.
The problem
Cold chains break in the dark. Nobody can prove it.
Exporters are asked to prove how food was kept. The trackers that could do it are too expensive to use once and throw away, go blind where there is no signal, and produce records anyone can edit.
₹1.53 lakh crore
of Indian produce is lost after harvest every year.
NABCONS study for the Ministry of Food Processing
₹9,200–12,000
per trip for a tracker that is thrown away after one use.
Elitech and Tive, Indian retail prices
July 2028
US importers must hand over tracking records for mango, papaya and guava within 24 hours.
US FDA food traceability rule
24,680
villages had no 4G, and a steel cold truck blocks the signal anyway.
Department of Telecommunications
Why hasn't this been done?
Five things stopped it. Each one has an answer.
The parts are cheap and common. So why is there no affordable tracker with records everyone trusts? We looked for the real reasons.
02 · the barrier
Everyone had to join one platform
Maersk and IBM's TradeLens shut down in 2023 because too few companies joined.
No sign-up: anyone checks the trip with one QR scan.
03 · the barrier
Trackers get thrown away
At ₹9,200 a trip, and costlier to send back than they are worth, single-use trackers are binned.
Cheap enough to own, and reused trip after trip.
04 · the barrier
No signal on the road
24,680 villages had no 4G, and steel trucks and containers block radio.
It stores everything offline, and syncs when signal returns.
05 · the barrier
Cheap sensors miss ethylene
A true ethylene cell costs about ₹13,000. Cheap ones can only guess.
One exact cell per truck, and a gas sensor on every Tag.
So we built
A Tag for every pallet and a Hub for every truck.
See how it fits together →How it works
Sense it. Sign it. Let anyone check it.
Three things happen to every reading. None of them needs a login, an app or trust in us.
01 · SENSE
Air, fruit, gas and shocks
Every 10 minutes the Tag reads the air, a steel probe pushed into the fruit, the ripening gas, and every knock. If someone chills only the Tag, the air and the fruit stop agreeing, and that mismatch is an alarm.
Two temperatures, on purpose
02 · SIGN
A chip that can't be copied
A secure chip signs each reading at the moment it is taken and links it to the one before. Its key can never be read out, so a copy can't fake readings and an edit can't hide.
Tamper-evident by design
03 · CHECK
Anyone, with one scan
Whoever scans the crate's QR code gets a page that redoes the maths in their own browser. If a single reading was changed, deleted or copied, it turns red at exactly that block.
No server to trust
The hardware
Built to survive the trip. Priced to be reused.
Two devices. The Tag rides on every pallet. The Hub rides on every truck, where its roof antennas can see the sky and the truck's power keeps it running.
The Tag · one per pallet
₹8.5k, reusable, sealed
- Sealed polycarbonate shell, silicone gasket, breather vent
- Steel food probe, air, gas and shock sensors, lid and light tamper
- Solar lid and heat harvester top up an 18650 battery
- Signs everything in a secure chip; keeps 16 MB of log offline
The Hub · one per truck
The Tags' window to the world
- Steel trucks block 4G and GPS, so the Hub carries roof antennas
- Talks to every Tag over long-range radio, then uploads for them
- Measures ethylene exactly, in ppm, once for the whole load
- Runs on the truck's own power
Real prototype
It's running on a bench right now.
Probe in, sensors reading, OLED showing live values, battery charging from the solar panel, inside a laser-cut case. These are our own photos.
One crate's journey
Every stop leaves a signed trace.
Follow a crate of Alphonso mangoes from Ratnagiri to Dubai, and who gains at every step.
1Farm, Ratnagiri
Tag on the pallet, probe in the fruit.
Farmer: proof the crop left in perfect shape
2Highway, no signal
Readings signed and stored; the Hub relays.
Transporter: proof the truck stayed cold
3Stop, Nashik
Box opened: a signed tamper alert.
Exporter: knows now, not weeks later
4Port, JNPT
Back in signal: the record syncs itself.
APEDA: export papers ready before loading
5At sea, ripening
Ethylene rising: sell this crate first.
Planet: less food thrown away
6Buyer, Dubai
Scans the QR: a green tick and full proof.
Everyone: no disputes, a fair price
Numbers we can defend
Cheaper after two trips. Lasting for months.
Conservative on purpose: cold, dark, and the battery losing charge by itself. Every input is on the Economics page, ready to change.
Cost per pallet
₹9,200 → ₹350
per trip, once the Tag has paid for itself
₹8.5k for the Tag once, a tenth of a ₹18k Hub, about ₹350 a trip in upkeep, and a battery kit every 10 trips. Break-even against a single-use tracker: trip 2.
Battery, worst case
2 wk · 4 mo
on its own 4G · through the Hub
In daily sun the solar lid covers what the Tag uses. Inside a dark truck it runs on the battery alone, and we count the cell's self-discharge and the cold.
Built rugged
IP67 · IK08
dust-tight, 1 m of water, impact-rated
Gasket, breather vent, rubber bumpers and mounts, stainless screws, a conformal-coated board. A design target we will torture-test before we sell one.
Impact
Good for the farmer, the exporter and the planet.
Farmers get paid for a load kept well. Exporters meet the rules. Less food, and fewer trackers, end up in the bin.
Social
Farmers get paid fairly for a good crop
- Proof of care: a load that left in perfect shape can't be unfairly rejected.
- Shoppers scan the QR and see the whole trip. No app, no login.
- Rented through India's 10,000 farmer groups (30 lakh farmers).
Economic
Tracking drops from ₹9,200 to under ₹500 a trip
- Small exporters meet US and EU rules without the per-trip bill.
- Government finds every crate of a bad batch in minutes, and gets transit temperatures APEDA's portal lacks.
- Insurers and courts settle claims on evidence nobody can rewrite.
Environment
One Tag replaces 20 throwaway trackers
- Warm or ripening crates are flagged early and sold first.
- Solar-charged and reused for years, not binned every trip.
- Fewer spoiled loads rotting into methane.
Don't take our word for it. Break it yourself.
Run a trip, tamper with the record, and watch the maths catch you. Two minutes with the guided tour, or open the dashboard and explore.