NFC Tools
New COLDCARD® Mk4 NFC Tools menu option under Advanced/Tools.
Show Address#
Same as USB show address but path and address format are provided via NFC.
Data format:
m/84'/0'/0'/300/0
p2wpkh
The second line, specifying the address format is optional and defaults to p2pkh (classic).
Sign Message#
Send message, path and address format over NFC and receive a signed Bitcoin message (after approval by the user).
Data Format:
Message to be signed should be a multiline text file. The first line is the message to be signed and is the only required line. Next is the derivation path to be used, and finally, an the address format to use.
My messsage today
m/84'/0'/0'/300/0
p2wpkh
File Share#
Share a file from SD card via NFC. For example a signed Bitcoin transaction or PSBT file can be transmitted this way.
Import Multisig#
With the help of a mobile wallet designed for multisig, the config file for a new multisig wallet can be received via NFC using this menu choice.