Overview
Arculus is a self-custody crypto wallet built into a metal card that you tap against your phone to approve a transaction. The keys that control your coins are created and kept inside the card, so they never sit on the phone or online. There is no cable, no battery, and nothing to charge.
The card is made by CompoSecure, a US manufacturer of metal payment cards, and pairs with a companion app for iPhone and Android. Cardano is one of the networks it handles: ADA can be stored, sent, received, and delegated to a stake pool from inside the app12. Bitcoin is among the other supported assets, which span a long list of tokens across many networks1.
Key Features
- Keys that never leave the card. Private keys are generated inside the card's chip using a hardware random-number generator and stay there, while the app on your phone holds only public account information3.
- Three things needed to approve anything. Moving funds takes the card in your hand, a six-digit PIN only you know, and your face or fingerprint on the phone3.
- Staking ADA without handing over the keys. The wallet's ADA balance can be delegated to a public stake pool from the app and redelegated with a tap, and Arculus adds no fee of its own on top of the pool's2.
- Nothing to plug in or charge. The stainless steel card has no battery, port, or Bluetooth radio, and talks to the phone over NFC, the short-range technology behind contactless payments, at a range of a few centimetres4.
- A recovery phrase that works elsewhere. Setup produces a standard 12- or 24-word phrase, shown once and stored by nobody, so the wallet can be rebuilt on other compatible software if the card goes missing35.
What to Expect
Setup runs from the app: you lay the card flat, hold the phone over it, create a wallet, choose a six-digit PIN, and write down the recovery phrase, typing it back once to confirm6. After that the card only comes out when you need to approve something, held against the phone until the transaction signs.
Day to day, the app shows balances, transaction history, and a gallery for Ethereum-based NFTs. Arculus charges nothing to send or receive, so you pay only the network's own fee5. Buying and swapping inside the app is passed to third-party providers, whose fees appear before you confirm7. The card can also sign for outside apps and marketplaces through WalletConnect7. Unlike hardware wallets with a screen of their own, transaction details are read on the phone before you tap the card.
For Cardano holders, delegating ADA to a stake pool earns rewards while the coins stay in your own wallet, and Arculus handles this natively2. Delegation applies to the wallet's whole ADA balance rather than a chosen slice, and ADA cannot be bought or swapped in the app, so it has to arrive from somewhere else12. Restoring a 24-word phrase also asks you to pick between Cardano's standard and legacy address styles, and the wrong choice shows an empty ADA balance until it is redone8.
