Identity the server verified
The account key is the IDi obtained through online mutual authentication. Merchants hold no cryptographic keys, and no balance is ever written to the card — so neither impersonation nor tampering is open to them.
Online prepaid payment platform
Just tap.
Pay or top up in an instant.
There is nothing for your customers to get hold of. The FeliCa they already carry becomes the payment method. Balances are held in a server-side ledger, and mutual authentication proves the card is genuine.
- No app to install
- No card to issue
One merchant API key — from Android, a desktop terminal, or the API.
One tap, nothing else
Paying and topping up are the same gesture: hold the card to the reader. There is nothing to work out.
No app, no dedicated card
The FeliCa your customers already carry becomes their Melon. No card to issue, no waiting.
Merchants start with one key
Paste in an API key and you are live — on Android or on the desktop.
* Melon works only with FeliCa that we have designated as supported. Not every FeliCa can be used.
Why Melon
A tap you can trust, by construction.
Trust starts with online mutual authentication on the server, not with what a card claims. On top of that sit an immutable ledger and an expiry scheme built for the regulation.
An append-only ledger
Every movement of money is recorded in a ledger that cannot be edited. Idempotency keys stop double spending, refunds return to the top-up they came from, and any balance can be rebuilt from the ledger at any time.
Six-month expiry, by design
Each top-up expires six months later, on the Japanese calendar. The exemption for instruments valid for no more than six months from issue is implemented strictly, auditably and immutably.
Transactions, refunds and settlement in one place
Balances, transactions, refunds, settlement and staff — merchants run the day from one portal, with each role seeing only what it needs.
How it works
From a tap to a settled payment.
The terminal only relays frames between the card and the server. The server holds the keys, and the payment is settled in the server's ledger.
The card is tapped
The merchant terminal polls the FeliCa and reads its IDm / PMm. The terminal holds no keys.
The server authenticates
The terminal relays the frames; the server drives mutual authentication with its keys and ends up with a verified IDi and an authenticated session.
The balance settles it
That session pays, tops up, reads the balance or refunds — and the ledger records it.
Supported cards
Your existing card just works.
The main FeliCa cards melon accepts.
Transit IC cardsthe nationwide 10
- Kitaca
- Suica
- TOICA
- ICOCA
- SUGOCA
- PASMO
- manaca
- PiTaPa
- はやかけん
- nimoca
E-money
- Rakuten Edy
- nanaco
- WAON
- QUICPay
- iD
- N+card
Cards not listed here may also work if they carry FeliCa system code 0x0003 (transit IC) or 0xFE00 (common area). Final support is at our designation.
For cardholders · optional
Your balance, on your phone.
You don’t need an app to pay with Melon. When you just want to check your balance, there’s Mobile Melon (Android, free).
- Tap your cardHold your card to the phone’s NFC and see the balance on the spot.
- Enter your card IDRegister it once, then just open the app to see your balance.
Get the Android app →Android
Available from GitHub releases (installing apps from unknown sources must be allowed).
Terminals
Any terminal, the same ledger.
Authenticated with a merchant API key. Idempotency keys keep a retry from charging twice.
Android app
Turns an NFC phone into a tap-and-done POS. A keypad and a confirm button keep a stray tap from becoming a payment.
NFC-F / FeliCaDownload →
Desktop terminal
For a fixed register with a PaSoRi reader attached. Launches as a browser kiosk.
Win / macOS / LinuxDownload →
REST API
Mutual authentication, payments, refunds and balance lookups over JSON. Integrate your own terminal or back office directly.
/v1GitHub →
Thinking about Melon?
Get in touch through our contact page for rollout and pricing. Already a merchant? Sign in from the portal.