cardware-btc v1.0.8

Cardware BTC NPM Library

This is the documentation for the BTC NPM package that communicates with the Cardware device.

The library requires an electrs endpoint to query the bitcoin blockchain.

It allows users to create a watch-only wallet on the web.

All data that is transferred between the web wallet and the Cardware device is done through scanning QR codes.

Users must first pair the web wallet with their Cardware device.

Once paired they are then able to view the BTC address of their Cardware device, see their confirmed and unconfirmed BTC balances and send BTC from their Cardware device.

When sending, the watch only wallet will create an unsigned transaction which will be split up into QR codes. The user will then be prompted to scan these QRcodes with their Cardware device. The user will then confirm the transactions details which will then create a signed transaction which their Cardware device will split up into QR codes. The web wallet then scans these QR codes, decodes them and broadcasts the transaction.

Documentation

Initialization

Code

import Wallet from 'cardware-btc'; 

New Wallet

This function initializes a wallet object in your web wallet. The zpub is received from the Cardware device after successfully pairing the web wallet and Cardware device. The pairing process involves scanning the pair QR codes from the Cardware device, extracting the zpub, then using it in creating the wallet object.

Parameters

Code

var wallet = await new Wallet(zpub, esplora_url, network);

Output

No outputs.

Sync

This function syncs your web wallet to make sure it has all the correct information to be able to get balances, construct unsigned transactions and broadcast transactions.

Parameters

No parameters.

Code

await wallet.sync();

Output

The output is a string.

Sync to Depth

This function syncs your web wallet with max depth as a parameter to make sure it has all the correct information to be able to get balances, construct unsigned transactions and broadcast transactions.

Parameters

Code

await wallet.sync_to_depth(max_depth);

Output

The output is a string.

Estimate Fees

This function estimates fees for a send transaction which takes a variable called number of blocks where the lower the number of blocks, the higher the estimated fee and the faster the transaction will confirm. Users can batch send transactions by populating multiple addresses and multiple amounts however the user must make sure both arrays have the same length.

Parameters

Code

let result = wallet.estimate_fee(addresses, amounts, number_of_blocks);

Output

The output is a uint64.

Estimate Sweep Fees

This function estimates fees for a max send transaction which takes a variable called number of blocks where the lower the number of blocks, the higher the estimated fee and the faster the transaction will confirm. This is called a sweep when a user wants to empty their wallet.

Parameters

Code

let result = wallet.estimate_sweep_fee(number_of_blocks);

Output

The output is a uint64.

Send

This function creates an unsigned transaction which it converts into a base64 string which it then splits up into chunks to be put into multiple QR codes. At the beginning of each chunk extra information is added. The extra information has the format of ( + index of QR code + / + total QR codes + ) + part of the unsigned transaction as a base64 string.

Parameters

Code

var qrcode_chunks = wallet.send(addresses, amounts, fee);

Output

The output is an array of strings.

Broadcast

This function needs a signed transaction as a base64 string. It gets this by scanning the QR codes on the Cardware device. When scanning the QR codes of the signed transaction from the Cardware device it follows the format of ( + index of QR code + / + total QR codes + ) + part of the signed transaction as a base64 string.

Parameters

Code

await wallet.broadcast(signed_transaction);

Output

The output is a strings.

Broadcast Multisig

This function needs an array of signed transactions as a list of base64 strings. It gets these by scanning the QR codes on the Cardware devices that are part of the multisig. When scanning the QR codes of the signed transaction from the Cardware device it follows the format of ( + index of QR code + / + total QR codes + ) + part of the signed transaction as a base64 string.

Parameters

Code

await wallet.broadcast_multisig(transaction_signatures);

Output

The output is a strings.

Address

This function returns the address of your Cardware device.

Parameters

No parameters.

Code

const result = wallet.address();

Output

The output is a string.

New Address

This function returns the address of your Cardware device at a certain depth.

Parameters

Code

const result = wallet.new_address(derivation_path);

Output

Balance

This function returns confirmed balance of your Cardware device.

Parameters

No parameters.

Code

const result = wallet.balance();

Output

The output is a unint64.

Unconfirmed Balance

This function returns unconfirmed balance of your Cardware device.

Parameters

No parameters.

Code

const result = wallet.unconfirmed_balance();

Output

The output is a unint64.