NFC Crypto Kit
Launch your card
NewCryptoCard Wallet: the card is the wallet

Crypto you
can hold.

Ship your own branded NFC card with the apps behind it. Customers tap the card to open their wallet, confirm every payment and keep their recovery phrase safe. Your team makes the cards on a laptop.

Design your card See it work
NTAG215 · 496 bytesArgon2id 64 MiBAES-256-GCMiOS · Android · macOS · Windows
EthereumBasePolygonBNB ChainArbitrumSolanaBitcoinSuiTronWalletConnect dApps
4
apps in one kit
1,559
automated tests across the apps
6
metal finishes, plus your own
0
servers holding your customers' keys

How it works

One tap does the work of a password.

01Hold the card to the phone

The phone reads the card through NFC. On iPhone it works even with the app closed.

02The wallet opens

The card replaces Face ID and passcodes. A card that isn't paired is turned away.

03Every payment waits for the card

Sends, swaps and dApp signatures are signed only after another tap.

04The phrase lives on the card too

Locked with a PIN of 8 to 12 digits. Lost the paper? NFC Recovery brings the words back.

NFC Crypto asking the user to tap their card NFC Crypto wallet home screen
✓Card read
Confirm payment
0.25 ETH
to 0x9858…Eda94 · Base
Network fee0.00004 ETH
CardMain card ·· 3eb3
Tap card to confirm

Backup unlocked

Opened with the card's PIN. Nothing leaves this phone.

For startups

Everything you need to put a card in a customer's hand.

Your brand on the card and in the apps

Your name, colours and finish on the metal, the same look on every screen.

Your domain behind every tap

Cards point to your site. With the app installed the tap opens it; without, people land on your page.

// one tap, one signature
await card.confirm(tx)
final sig = wallet.sign(tx)
// key wiped after use

Full source code

Flutter apps and a Python studio you own and can change.

Batch programNTAG215

Cards by the box

Program a stack of blank cards in a row with the ACR122U reader.

OFFLINE

Recovery without a server

The phrase comes back from the card and its PIN, with no account and no internet.

iPhoneAndroidmacOSWindows

Every platform your customers and team use

Phone apps for iOS and Android; Card Studio for macOS and Windows.

Backup cards with their own PIN

Clone a card for a customer in the app or the studio; each copy can get its own PIN.

The apps

Four apps, one card format.

A card made in the studio opens in the wallet. A backup saved by the wallet opens in the recovery app. Every app reads and writes the same bytes.

For your customers

NFC Crypto

A full multi-chain wallet. The card opens the app, confirms payments and can carry the recovery phrase.

Tap to openSwapsdAppsPhrase on card
NFC Crypto welcome screen

For your customers

CryptoCard Wallet

The card is the wallet. The phrase lives only on the card and the phone just watches. Tap and enter the PIN to send.

Per-card PINBackup cardsEVMTestnet first
CryptoCard welcome screen

For your customers

NFC Recovery

Lost the paper? Tap the card, enter its PIN, see the words. Works offline, saves nothing, slows down guessing.

OfflinePIN throttleAuto-hide
NFC Recovery home screen

For your team

Card Studio

A desktop app for the ACR122U reader. Program cards one by one or in batches, clone them with a new PIN, track who got which card.

macOSWindowsBatchCSV
Card Studio reading a card

Real screens

Straight from the apps.

NFC Crypto · Tap to open
NFC Crypto · Welcome
NFC Crypto · Wallet
NFC Crypto · Card settings
NFC Crypto · Settings
NFC Crypto · Discover
CryptoCard · Welcome
CryptoCard · New wallet
CryptoCard · Choose a finish
NFC Recovery · Read card

Design a card

Make the card your customers will carry.

Upload your logo, pick a finish or your own colours, turn it over, tap it. The same finishes ship in the apps.

Logo
PNG or SVG, light on transparent works best. It stays in your browser.
Finish
Your own colours
Material
Engraving
Chip
Spec for your print shop 

            

          

        

      

    

  


  

    

      
Card Studio · Reader
Card Studio showing a blank NTAG215 card on the reader

      

        
Card Studio

        
From a box of blank cards to a customer's pocket.

        
    
          
  1. Buy NTAG215 cardsAbout $1 each in bulk; NTAG216 works too.
    2. 
          
  2. Program themOne by one or in a batch. Each card gets its own ID and your link.
    3. 
          
  3. Assign and shipLink each card to a customer, mark it shipped, export the list.
    4. 
          
  4. Make backup cardsClone a card for a customer; each copy can get its own PIN.
    5. 
        

      

    

  


  

    

      
Security
What protects the money, in plain numbers.

      

        
Phrase on the card
Argon2id + AES-256-GCM
64 MiB of memory and 4 passes for every PIN guess, then authenticated encryption.

        
PIN
8–12 digits
For every new PIN. Repeats and runs like 12345678 are refused. Wrong tries make you wait longer each time.

        
Keys
Never on a server
NFC Crypto keeps keys on the phone. CryptoCard holds them only for the moment of signing.

        
Writes
Read back, then trust
Every write is read back and compared. A card that carries a backup is never overwritten by pairing.

        
Erase
Every byte zeroed
The studio clears the whole card and checks it, so a returned card keeps nothing.

        
Know the limit
NTAG215 can be copied
Fine for pilots. For production, move to NTAG 424 DNA or secure-element cards.

      

    

  


  

    

      
FAQ
Questions startups ask first.

      

        
Which cards do we need?
NTAG215 or NTAG216 NFC cards, the common kind sold by the hundred. NTAG213 is too small to hold a recovery phrase. For production volume we recommend NTAG 424 DNA, which can prove a card is genuine.

        
Does it work on iPhone?
Yes. The phone apps read cards on iPhone and Android, and both wallets write them too (NFC Recovery only reads). On iPhone a tap with the app closed shows a notification that opens your app through your domain.

        
What happens if a customer loses the card?
In NFC Crypto the wallet still lives on the phone and the recovery phrase turns the card requirement off. With CryptoCard, a backup card restores the wallet, or the phrase if the customer wrote it down (the app shows it with a card and its PIN).

        
Can someone copy a card?
An NTAG215 can be copied by anyone holding it. The copy still needs the PIN, and every guess costs 64 MiB of memory work, so use 8 digits or more. Secure-element cards remove this limit.

        
Do you ever hold our customers' keys?
No. There is no server in the signing path. Keys stay on the customer's phone or on their card.

        
How long does a launch take?
The apps exist today. Rebranding, your domain and a first programmed batch of cards is a matter of weeks, followed by store review for the phone apps.

      

    

  


  

    

      
      
Launch

      
Your card.
Your brand.

      
Get the four apps with full source, your name and colours, and help programming the first batch of cards.

      

        Talk to MIKODES
        Design your card