Requirements
tools, hardware, cards and accounts.
What you need on your computer, which phones and cards work, and which accounts you pay for yourself. There is no server to run and no Firebase project.
01On your computer
| Tool | Version | Needed for | |
|---|---|---|---|
| Flutter (with Dart) | Flutter 3.41 or newer, which ships Dart 3.11. CryptoCard Wallet and NFC Recovery ask for Dart ^3.11.1 (pubspec.yaml). | The three phone apps | Required |
| Xcode with CocoaPods | Xcode 16 or newer, on a Mac | iOS builds | Required for iOS |
| Android Studio or the Android SDK | SDK platform 36 (compileSdk and targetSdk are 36 in each android/app/build.gradle.kts) | Android builds | Required for Android |
| Python | 3.10 or newer. The python3 that comes with macOS is 3.9 and is too old: install a newer one with Homebrew (brew install python) or from python.org. | Card Studio and the tool/nfc desk tool | Required for Card Studio |
| Operating system for Card Studio | macOS or Windows | Card Studio | Required for Card Studio |
02Phones
| App | iOS | Android |
|---|---|---|
| NFC Crypto | iOS 15.5 or newer | Android 7.0 (API 24) or newer |
| CryptoCard Wallet | iOS 15.0 or newer | Android 7.0 (API 24) or newer |
| NFC Recovery | iOS 15.0 or newer | Android 7.0 (API 24) or newer |
Reading cards needs a phone with NFC: an iPhone XS or newer, or an Android phone with NFC turned on. iOS simulators and Android emulators have no NFC. They run the apps and show the screens, but cannot read a card.
Older iPhones (7 to X) can only read a card from inside the app, with Test a card. They cannot open the app from a tap while it is closed.
03NFC cards
| Chip | Works? | Why |
|---|---|---|
| NXP NTAG215 (504 bytes) | Yes | Holds the card link, the Android record, a recovery backup and the receive addresses together. |
| NXP NTAG216 | Yes | Larger than NTAG215. |
| NXP NTAG213 | Link only | Too small for a recovery backup. Card Studio refuses to clone a backup onto it. |
| MIFARE Classic | No | iPhones cannot read it. |
| NTAG 424 DNA, secure-element cards | Not supported | Recommended for copy-proof cards in the future, but not built into this kit. See Security. |
Do not use "Lock tag" or a password in any other NFC writing app. A locked card can never be paired again. Card Studio and the apps never lock cards.
04Card reader (for Card Studio)
An ACS ACR122U USB reader. It is the only reader model the code is written and tested for (apps/card_studio/studio/reader.py). macOS already has its driver. On Windows, install the ACR122U PC/SC driver from the ACS website if Windows does not list the reader.
No reader yet? Card Studio has a simulated reader, so you can learn it first.
05Accounts and services
| Item | Used for | |
|---|---|---|
| Apple Developer Program membership and your Apple Team ID | Building for real iPhones, the NFC Tag Reading and Associated Domains capabilities, the App Store, and the apple-app-site-association file on your card domain | Required for iOS |
| Google Play developer account | Publishing the Android apps | Required for Play |
| A domain with HTTPS | The link written on every card, and the app-link files. See Card host setup. | Required for real use |
| Reown project ID | WalletConnect (connecting to dApps) in NFC Crypto | Optional |
| 0x and 1inch API keys | Swap quotes from those aggregators on EVM networks | Optional |
| Block explorer, Alchemy, Birdeye, CoinGecko keys | History, balances and prices with higher rate limits | Optional |
All API keys are listed on the Configuration page. You pay each provider directly, under your own account. Most have a free tier.
06Not included in the purchase
- Physical NFC cards, card printing and the card reader.
- Hosting and the domain for your card links.
- Apple Developer and Google Play accounts, app signing and store review.
- Third-party API keys and subscriptions.
- Blockchain network fees.
- A server or custody of any kind. Keys stay on the user's phone or card.
- Fiat on-ramp or off-ramp.
- Copy-proof card authentication (NTAG 424 DNA or secure-element cards).
- Legal, KYC/AML or licensing work for where you sell.
- Installation and customization done for you.