- Coldcard device
- A laptop or desktop computer
- Micro SD card
- Micro SD card adapter (if your computer does not have a micro SD card slot)
When your Coldcard is powered up and unlocked with your PIN, click the checkmark button to select "Ready To Sign."
If there is only one .psbt file on the Coldcard, it will immediately begin the transaction verification and signing process. If there are multiple files then you will need to select which one to sign.
Once you finish verifying the transaction details, the Coldcard will save the signed psbt to the SD card.
Now that the transaction’s signature is copied to the SD card, you’re ready to transfer the signature back to your computer to complete the signing process.
Remove the SD card from the Coldcard and insert it into your computer.
Back in your web browser, click “Next,” then drag and drop the file ending in "-part.psbt" into the window when prompted.
We recommend deleting the -part.psbt file from the micro SD card once finished uploading.
If you’re signing a transaction, you’ll need to give your other signatures to the transaction, if necessary, and complete the transaction within Casa App.