In your Casa app, you'll notice that you have the option to use and interact with TBTC (Testnet bitcoin).
TBTC refers to the coins that are sent on bitcoin's testnet. The testnet is an alternative bitcoin blockchain, which is used only for for testing.
Testnet coins (TBTC) are separate and distinct from actual bitcoins (BTC), and do not have real value as an asset. They also should not be confused with "tBTC," a type of wrapped bitcoin for use on the ethereum network.
Why use TBTC?
Having the option to enable and use a TBTC wallet in your Casa app enables you to test your Casa key setup without having to use real bitcoin.
Do I need to use TBTC?
While it's not necessary to test your setup with TBTC, we want you be be as comfortable as possible with your key management before funding your Casa app, so the option is there to test things like health checks and key rotation.
How do I get TBTC?
You can obtain TBTC by going to any numbers of TBTC faucets available online. Some examples of currently active TBTC faucets are:
https://coinfaucet.eu/en/btc-testnet/
https://bitcoinfaucet.uo1.net/
https://tbtc.bitaps.com/
Casa does not have the capability to send TBTC. To acquire TBTC, please explore various online faucets that provide these testnet coins.
How do I remove or hide the TBTC wallet?
The TBTC wallet is enabled by default in your Casa app, but you can toggle whether or not to view it from your app's Settings ⚙️ here, which will hide the TBTC wallet:
Special note for users of Ledger Nano S/S+ and Ledger Nano X:
If you're using Testnet on a Ledger device, you need to make sure you have the Testnet bitcoin app installed on your Ledger and are using that instead of the normal bitcoin app. To install this from Ledger Live, you need to toggle on Developer Mode by going to Settings ⚙️ > Experimental features > Developer mode. Click "My Ledger" in Ledger Live's sidebar, then connect and unlock your Ledger. Enable Manager on the Ledger itself, then search for Bitcoin Test and install the app on your Ledger. Without the Testnet bitcoin app on the Ledger, you're able to sign Testnet transactions, but the addresses won't match.
If this information ever becomes out of date, please check Ledger's guide to enabling Testnet on their own website.
Special note for Coldcard users:
If you're using Testnet on a Coldcard device, you need to switch the device into Testnet mode at Settings ⚙️ > Blockchain > Testnet: BTC