btcwallet

btcwallet is a daemon handling bitcoin wallet functionality for a single user. It acts as both an RPC client to btcd and an RPC server for wallet clients and legacy RPC applications.

Public and private keys are derived using the hierarchical deterministic format described by BIP0032. Unencrypted private keys are not supported and are never written to disk. btcwallet uses the m/44'/<coin type>'/<account>'/<branch>/<address index> HD path for all derived addresses, as described by BIP0044.

Due to the sensitive nature of public data in a BIP0032 wallet, btcwallet provides the option of encrypting not just private keys, but public data as well. This is intended to thwart privacy risks where a wallet file is compromised without exposing all current and future addresses (public keys) managed by the wallet. While access to this information would not allow an attacker to spend or steal coins, it does mean they could track all transactions involving your addresses and therefore know your exact balance. In a future release, public data encryption will extend to transactions as well.

btcwallet is not an SPV client and requires connecting to a local or remote btcd instance for asynchronous blockchain queries and notifications over websockets. Full btcd installation instructions can be found here. An alternative SPV mode that is compatible with btcd and Bitcoin Core is planned for a future release.

Wallet clients can use one of two RPC servers:

1. A legacy JSON-RPC server mostly compatible with Bitcoin Core

   The JSON-RPC server exists to ease the migration of wallet applications from Core, but complete compatibility is not guaranteed. Some portions of the API (and especially accounts) have to work differently due to other design decisions (mostly due to BIP0044). However, if you find a compatibility issue and feel that it could be reasonably supported, please report an issue. This server is enabled by default.

2. An experimental gRPC server

   The gRPC server uses a new API built for btcwallet, but the API is not stabilized and the server is feature gated behind a config option (--experimentalrpclisten). If you don't mind applications breaking due to API changes, don't want to deal with issues of the legacy API, or need notifications for changes to the wallet, this is the RPC server to use. The gRPC server is documented here.

Installation and updating

Windows - MSIs Available

Install the latest MSIs available here:

https://github.com/btcsuite/btcd/releases

https://github.com/btcsuite/btcwallet/releases

Windows/Linux/BSD/POSIX - Build from source

Building or updating from source requires the following build dependencies:

• Go 1.5 or 1.6

  Installation instructions can be found here: http://golang.org/doc/install. It is recommended to add $GOPATH/bin to your PATH at this point.

  Note: If you are using Go 1.5, you must manually enable the vendor experiment by setting the GO15VENDOREXPERIMENT environment variable to 1. This step is not required for Go 1.6.

• Glide

  Glide is used to manage project dependencies and provide reproducible builds. To install:

  go get -u github.com/Masterminds/glide

Unfortunately, the use of glide prevents a handy tool such as go get from automatically downloading, building, and installing the source in a single command. Instead, the latest project and dependency sources must be first obtained manually with git and glide, and then go is used to build and install the project.

Getting the source:

For a first time installation, the project and dependency sources can be obtained manually with git and glide (create directories as needed):

git clone https://github.com/btcsuite/btcwallet $GOPATH/src/github.com/btcsuite/btcwallet
cd $GOPATH/src/github.com/btcsuite/btcwallet
glide install

To update an existing source tree, pull the latest changes and install the matching dependencies:

cd $GOPATH/src/github.com/btcsuite/btcwallet
git pull
glide install

Building/Installing:

The go tool is used to build or install (to GOPATH) the project. Some example build instructions are provided below (all must run from the btcwallet project directory).

To build and install btcwallet and all helper commands (in the cmd directory) to $GOPATH/bin/, as well as installing all compiled packages to $GOPATH/pkg/ (use this if you are unsure which command to run):

go install . ./cmd/...

To build a btcwallet executable and install it to $GOPATH/bin/:

go install

To build a btcwallet executable and place it in the current directory:

go build

Getting Started

The following instructions detail how to get started with btcwallet connecting to a localhost btcd. Commands should be run in cmd.exe or PowerShell on Windows, or any terminal emulator on *nix.

• Run the following command to start btcd:

btcd -u rpcuser -P rpcpass

• Run the following command to create a wallet:

btcwallet -u rpcuser -P rpcpass --create

• Run the following command to start btcwallet:

btcwallet -u rpcuser -P rpcpass

If everything appears to be working, it is recommended at this point to copy the sample btcd and btcwallet configurations and update with your RPC username and password.

PowerShell (Installed from MSI):

PS> cp "$env:ProgramFiles\Btcd Suite\Btcd\sample-btcd.conf" $env:LOCALAPPDATA\Btcd\btcd.conf
PS> cp "$env:ProgramFiles\Btcd Suite\Btcwallet\sample-btcwallet.conf" $env:LOCALAPPDATA\Btcwallet\btcwallet.conf
PS> $editor $env:LOCALAPPDATA\Btcd\btcd.conf
PS> $editor $env:LOCALAPPDATA\Btcwallet\btcwallet.conf

PowerShell (Installed from source):

PS> cp $env:GOPATH\src\github.com\btcsuite\btcd\sample-btcd.conf $env:LOCALAPPDATA\Btcd\btcd.conf
PS> cp $env:GOPATH\src\github.com\btcsuite\btcwallet\sample-btcwallet.conf $env:LOCALAPPDATA\Btcwallet\btcwallet.conf
PS> $editor $env:LOCALAPPDATA\Btcd\btcd.conf
PS> $editor $env:LOCALAPPDATA\Btcwallet\btcwallet.conf

Linux/BSD/POSIX (Installed from source):

$ cp $GOPATH/src/github.com/btcsuite/btcd/sample-btcd.conf ~/.btcd/btcd.conf
$ cp $GOPATH/src/github.com/btcsuite/btcwallet/sample-btcwallet.conf ~/.btcwallet/btcwallet.conf
$ $EDITOR ~/.btcd/btcd.conf
$ $EDITOR ~/.btcwallet/btcwallet.conf

Issue Tracker

The integrated github issue tracker is used for this project.

GPG Verification Key

All official release tags are signed by Conformal so users can ensure the code has not been tampered with and is coming from the btcsuite developers. To verify the signature perform the following:

• Download the public key from the Conformal website at https://opensource.conformal.com/GIT-GPG-KEY-conformal.txt

• Import the public key into your GPG keyring:

  gpg --import GIT-GPG-KEY-conformal.txt

• Verify the release tag with the following command where TAG_NAME is a placeholder for the specific tag:

  git tag -v TAG_NAME

License

btcwallet is licensed under the liberal ISC License.