Wasabi Wallet companion app
Hardware Wallets must be used in combination with a mobile or desktop Bitcoin Wallet app
In this guide, we will teach you how to use the Coldcard in combination with a desktop application called Wasabi Wallet.
The best way to think about the Coldcard is that it is simply a sophisticated calculator that will take care of all the cryptographic algorithms that protect your Bitcoin wallet.
The device doesn't have access to the internet and does not come with a user interface.
Instead, it is designed to be connected to be used in combination with another mobile or desktop Bitcoin wallet, such as Wasabi Wallet.
To view your Bitcoin balance, to monitor your incoming transactions and to make Bitcoin payments you need access to the Bitcoin Network, which requires the internet.
The purpose of Wasabi Wallet is to connect to the Bitcoin Network and provide a nice user interface which lets you receive, send and monitor payments.
When making Bitcoin transactions, you will enter the amount you want to send and the destination Bitcoin address into the Wasabi Wallet interface. You then export that transaction to a microSD card so that it can then be entered into your Coldcard and the transaction approved.
This is what we call an "air-gapped" transaction, meaning that there is never a direct connection between your Coldcard device and the Internet.
If you only want to monitor your balance or receive Bitcoin payments and monitor transactions, you do not need to use the microSD card (after the initial connection). This is commonly referred to as "watch-only" mode.