Coldcard - Cloud

Coldcard with Bluewallet - Using Dropbox

In this video you will see the usage of PSBT, watch-only wallets. And how to send transactions offline with your Coldcard and Bluewallet. Using dropbox on this example.

  • Start the Coldcard device, go to AdvancedMicroSD CardExport WalletElectrum Wallet.
  • Put the SD card into Coldcard. Choose Native Segwit. It should create wallet skeleton file on SD card.
  • Put the SD card into the PC and move the created wallet skeleton file onto the Dropbox folder.
  • Grab the iPhone, launch BlueWallet, tap Create a walletImport walletscan QR or import from filetap file icon and choose your wallet skeleton file. It should import your Coldcard wallet as watch-only.
  • Create a transaction from this watch-only wallet, when prompted - export it to a file and save it in Dropbox folder.
  • Put the SD card back into the PC, and move the transaction file from Dropbox folder to the SD card.
  • Put the SD card into the Coldcard, go to Ready To Sign and proceed with signing the transaction.
  • Put the SD card into the PC. There should be 2 new files: a file with tge transaction hex that is ready to broadcast (*-final.txn), and a signed transaction file (*-signed.psbt).Let us finish the transaction on iPhone, so move signed transaction file to Dropbox.
  • On the iPhone, tap Open Signed Transaction, and choose the signed transaction file from your Dropbox. - Tap Send now!

PS: Take in consideration that we used dropbox on this example, but anything will work, File system, iCloud, Bluetooth, AirDrop,, direct lightning to sd card adapter, etc

Coldcard with Bluewallet
Coldcard - Watch-only