UPI wallet simulation app for demos and training (no code)

A bank's training team in Pune needs to teach 200 new staff how a UPI payment looks from the customer's side, without 200 real accounts. A UX designer in Bengaluru wants a portfolio piece that behaves like a wallet, not a click-through of static screens. A fintech founder needs something on a phone for an investor meeting next week, before the licence, the bank partner or a single rupee of real money. All three want the same thing: a wallet that looks and behaves like the real one, is obviously a simulation, and can be reset in one tap.

Building this with real payment SDKs is the wrong tool: it needs merchant onboarding, a licensed provider and compliance you do not have yet. Describing it to App Builder Agent gives you a React Native app where the balance, the PIN, the QR scan and the history are all real code on the device, and the money is not. You can watch it in the phone preview, scan a QR in the simulator, download an APK and put it in a trainee's hand the same afternoon.

What a UPI wallet simulation must handle

• A clear "demo mode" label — On the splash screen, the home screen and every receipt, so nobody mistakes it for a live app.
• Onboarding that looks right — Mobile number, a simulated OTP, a demo UPI id like name@demo, and a 4-digit PIN set on first run.
• Balance and a linked "bank" — A preset balance you can edit from a hidden settings screen, so a trainer can set ₹10,000 or ₹37.50.
• Send money three ways — To a UPI id, to a mobile number from a contact list, and by scanning a QR; each ending in the PIN sheet and a success or failure screen.
• Receive and request — A QR that encodes the demo id and amount, and a request that appears in the other party's simulated inbox.
• Transaction history — Reference number, time, counterparty, status (success, pending, failed), searchable and filterable by month.
• Deliberate failures — Insufficient balance, wrong PIN three times, a "bank server busy" pending state, because training is about what goes wrong.
• Reset and seed — Wipe everything and reload a realistic set of 30 transactions for the next demo.

Build it with App Builder Agent, step by step

1. Create a mobile app project and say "simulation" in the first line. The agent then builds the payment flows as demo payments on the device rather than looking for a gateway, and labels the app accordingly.
2. Describe the wallet screen by screen. Real names, real-looking amounts, and the failure cases you want to show.
   Build a UPI-style wallet SIMULATION for staff training; no real money, show "Demo mode" on every screen. Onboarding: mobile number, fake OTP 1234, choose a demo UPI id ending @demo, set a 4-digit PIN. Home: balance starting at ₹10,000, quick actions Scan QR, Send to UPI id, Send to mobile, Receive, Request. Sending asks amount and note, then PIN in a bottom sheet, then a success screen with a 12-digit reference and a share button; fail with "Insufficient balance" or "Incorrect PIN" (lock after 3 tries for 30 seconds). Receive shows a QR encoding the demo id and optional amount. History with filters by month and status, and a details screen per transaction. Hidden trainer menu (long-press the logo): set balance, seed 30 sample transactions, reset app. Store everything on the device with SQLite. Blue and white design, Indian rupee formatting like ₹1,23,456.00, English and Hindi labels.
3. Run a payment in the preview. Open the phone preview, send ₹500 to a contact, enter the wrong PIN twice and the right one once, and check the reference number lands in history. Use the Simulate panel's camera to scan a demo QR image and confirm the amount pre-fills.
4. Add the training scenarios. These are what a trainer actually demonstrates.
   Add a "Scenarios" screen in the trainer menu: a pending transaction that resolves after 60 seconds, a failed transaction with money auto-refunded after 2 minutes, a duplicate payment warning when the same amount goes to the same id within a minute, and a daily limit of ₹1,00,000 with the right error text.
5. Download the APK and hand it out. Press Download APK in the Preview tab; the test build installs on any Android phone without a store. Name the app "Wallet Demo" and keep the banner. If you ever go for a store listing, the signed build is there, but a simulation should say it is one in the listing too.

Prompts that work well

The same simulation serves different audiences with a different emphasis:

Common mistakes (and the fix)

• Forgetting to say "simulation". Without it the agent may try to integrate a real provider, which the preview cannot run and which you do not want. Put it in the first sentence and ask for the demo label.
• Making it look like a specific real app. Copying another company's logo, colours and name is a trademark problem. Use your own name and palette; the flows are what matter.
• Sharing an APK that says nothing about being fake. A trainee's relative could think it is real. Keep "Demo mode" on the splash screen and every receipt, and name the package something like com.yourcompany.walletdemo.
• No reset. After one class the history is a mess. The trainer menu with reset and seed is not optional.
• Only happy paths. Training and prototypes are judged on the wrong-PIN and pending screens. Ask for them explicitly.
• Rupee formatting from the US. ₹1,23,456.00 uses Indian grouping; say so or you get ₹123,456.00.

Make it feel finished

• A haptic tap and a short sound on success, and a distinct one on failure.
• A recent contacts row on the home screen, ordered by last payment.
• A receipt that can be shared as an image, watermarked "Demo".
• Bilingual labels switchable in settings, with the amount always in numerals.
• A one-screen "how this simulation works" page for trainers, reachable from the hidden menu.

Installing, publishing and next steps

The AI app builder page explains the phone preview, the Simulate panel and how demo payments are handled; real payment gateways are not run inside apps, which is exactly right for a simulation. Compare finished examples in the ready-made login & dashboard apps gallery, where several use the same PIN, onboarding and history patterns.

If the wallet is one part of a bigger prototype, the login, signup and dashboard guide shows the account side, and the expense tracker guide turns the same history screen into something people use for real. Open the builder, paste the prompt above, and keep the word "simulation" in it.

Frequently asked