TapFlashPayPal AI Hackathon

Try TapFlash in five minutes

In Nairobi, a clean public restroom that is open when you need it is hard to find, and the people who keep restrooms clean are often paid late, in cash. TapFlash is a WhatsApp bot that finds the restroom, takes the payment with PayPal, refunds failed visits, and pays operators and cleaners as soon as their work is approved.

Everything below runs live on this server. Do the four stops in order. Stop 1 is two separate visits, because one payment can only end one way: either the door opens and the hold is charged, or the visit fails and the hold is released.

PayPal sandbox buyer, for stop 1
Email
sb-ej80l53771973@personal.example.com
Password
l(Fp6Xu*
  • PayPal sandbox: real API calls, test money
  • Google Gemini connected
  • Also on WhatsApp: +254182848213
The TapFlash chat: a request in Swahili answered with four nearby restrooms, with photos, distance and price
1

Two visits: one works, one fails

Visit 1: the door opens.

  1. In the chat, type Niko Kencom, nataka choo safi: Swahili for "I'm at Kencom, I want a clean toilet". Gemini understands and answers in Swahili.
  2. Pick a restroom, then Pay and PayPal. Log in with the sandbox buyer above. PayPal holds the money; it is not charged yet.
  3. The receipt, the walking route and the access QR code arrive in the chat.
  4. Open the door check (stop 2) and scan that QR code, or type its 6-digit code. Press Let them in: PayPal now takes the held payment.
  5. Scan the same code again: it says Already used.

Visit 2: the door is locked.

  1. Start a new visit and pay again, the same way. Do not scan this one.
  2. Write The door was locked. Gemini reviews it and the code releases the hold: you are never charged.
  3. Limits the code enforces on this server: an automatic refund only within 120 minutes of paying, and at most 20 per person per day (raised from the default of 1 so judges can test more than once). Staff can still refund or release from the dashboard.
Open the chat
The chat after choosing PayPal: the amount in shillings and dollars and the PayPal sandbox payment link
2

Walk in: the attendant scans you

  1. Open the door check on a phone (no password).
  2. Use it on visit 1 of stop 1: scan the QR code or type the 6-digit code, press "Let them in".
  3. Scan it again: "Already used", so a shared screenshot doesn't get a second person in. Do not scan visit 2: that hold was released, and the door check would say so.
The door check on the attendant's phone: Let them in
3

Send a cleaner's photo

  1. Press the button. It sends the restroom's own demo photo as the demo cleaner, Kenyatta Avenue. Gemini checks it against the restroom's own photo and scores it.
  2. A clean one is paid a bonus with PayPal Payouts. A doubtful one waits for staff in the dashboard (stop 4). Press it twice and the second one is refused as "sent before"; other judges' photos do not count.

4

Run it as the operator

  1. Your two visits: one charged after the door check, one released after your complaint, with Gemini's review.
  2. Tick restroom operators and pay their share with PayPal Payouts.
  3. Under Cleaning bonuses, see your photo and approve a waiting one: PayPal pays them at once.
  4. Back in the chat, search again: that restroom now says cleaned 1 min ago and comes first when you ask for the cleanest. The cleaner's checked work is what the next visitor sees.
The operators' dashboard: money owed, with a Pay everyone with PayPal button, and what needs a decision

Why it matters

In January 2026 the US CDC reported that public toilets in Kenya that are not cleaned well spread diarrhoeal illness and worsen cholera and mpox outbreaks. It found high turnover and low morale among cleaners, and skipped disinfection, and what worked was checking the work and giving feedback (CDC). Where private operators ran Nairobi's public toilets, each served 500 to 1,000 visitors a day (World Bank WSP).

In Kampala, a busy public toilet takes up to Shs120,000 on a good day, in cash and with no record (Daily Monitor). TapFlash turns that into PayPal payments with a record an operator can show a bank.

TapFlash checks every cleaning with a photo, pays the cleaner at once with PayPal, and shows the next visitor that the restroom was just cleaned.

Real

PayPal Orders, Refunds, Payouts and webhooks (sandbox), Google Gemini, the WhatsApp bot, the QR door check.

Test money

PayPal runs in its sandbox, as the hackathon asks. Going live is a settings change, not a code change.

Sample data

The five Nairobi restrooms and their operators are examples. Payments, refunds and payouts you make here are real sandbox ones.