Bitcoin wallet Service

Bitcoin Wallet / July 23, 2017

A Multisig HD Bitcore Wallet Service.

Bitcore Wallet Service facilitates multisig HD wallets creation and operation through a (hopefully) simple and intuitive REST API.

BWS can usually be installed within minutes and accommodates all the needed infrastructure for peers in a multisig wallet to communicate and operate – with minimum server trust.

See [Bitcore-wallet-client] for the official client library that communicates to BWS and verifies its response. Also check [Bitcore-wallet] for a simple CLI wallet implementation that relays on BWS.

BWS is been used in production enviroments for Copay Wallet, Bitpay App wallet and others.

More about BWS at

npm install bitcore-wallet-service npm start

This will launch the BWS service (with default settings) at

BWS needs mongoDB. You can configure the connection at config.js

BWS uses by default a Request Rate Limitation to CreateWallet endpoint. If you need to modify it, check defaults.js' Defaults.RateLimit

Private keys are never sent to BWS. Copayers store them locally.
Extended public keys are stored on BWS. This allows BWS to easily check wallet balance, send offline notifications to copayers, etc.
During wallet creation, the initial copayer creates a wallet secret that contains a private key. All copayers need to prove they have the secret by signing their information with this private key when joining the wallet. The secret should be shared using secured channels.
All BWS responses are verified:
Addresses and change addresses are derived independently and locally by the copayers from their local data.
TX Proposals templates are signed by copayers and verified by others, so the BWS cannot create or tamper with them.

Authentication

In order to access a wallet, clients are required to send the headers:

x-identity x-signature

Identity is the Peer-ID, this will identify the peer and its wallet. Signature is the current request signature, using requestSigningKey, the m/1/1 derivative of the Extended Private Key.

GET Endpoints

/v1/wallets/: Get wallet information

Returns:

/v1/txhistory/: Get Wallet's transaction history

Optional Arguments:

skip: Records to skip from the result (defaults to 0)
limit: Total number of records to return (return all available records if not specified).

History of incoming and outgoing transactions of the wallet. The list is paginated using the skip & limit params. Each item has the following fields:
action ('sent', 'received', 'moved')
amount
fees
time
addressTo
confirmations
proposalId
creatorName
message
actions array ['createdOn', 'type', 'copayerId', 'copayerName', 'comment']

/v1/txproposals/: Get Wallet's pending transaction proposals and their status Returns:

/v1/addresses/: Get Wallet's main addresses (does not include change addresses)

/v1/balance/: Get Wallet's balance

totalAmount: Wallet's total balance
lockedAmount: Current balance of outstanding transaction proposals, that cannot be used on new transactions.
availableAmount: Funds available for new proposals.
totalConfirmedAmount: Same as totalAmount for confirmed UTXOs only.
lockedConfirmedAmount: Same as lockedAmount for confirmed UTXOs only.
availableConfirmedAmount: Same as availableAmount for confirmed UTXOs only.
byAddress array ['address', 'path', 'amount']: A list of addresses holding funds.
totalKbToSendMax: An estimation of the number of KiB required to include all available UTXOs in a tx (including unconfirmed).

POST Endpoints

/v1/wallets/: Create a new Wallet

Required Arguments:

name: Name of the wallet
m: Number of required peers to sign transactions
n: Number of total peers on the wallet
pubKey: Wallet Creation Public key to check joining copayer's signatures (the private key is unknown by BWS and must be communicated by the creator peer to other peers).

walletId: Id of the new created wallet

/v1/wallets/:id/copayers/: Join a Wallet in creation Required Arguments:

walletId: Id of the wallet to join
name: Copayer Name
xPubKey - Extended Public Key for this copayer.
requestPubKey - Public Key used to check requests from this copayer.
copayerSignature - Signature used by other copayers to verify that the copayer joining knows the wallet secret.

copayerId: Assigned ID of the copayer (to be used on x-identity header)
wallet: Object with wallet's information

/v1/txproposals/: Add a new transaction proposal Required Arguments:

toAddress: RCPT Bitcoin address.
amount: amount (in satoshis) of the mount proposed to be transfered
proposalsSignature: Signature of the proposal by the creator peer, using prososalSigningKey.
(opt) message: Encrypted private message to peers.
(opt) payProUrl: Paypro URL for peers to verify TX
(opt) feePerKb: Use an alternative fee per KB for this TX.
(opt) excludeUnconfirmedUtxos: Do not use UTXOs of unconfirmed transactions as inputs for this TX.

/v1/addresses/: Request a new main address from wallet

/v1/txproposals/:id/signatures/: Sign a transaction proposal