dcrwallet

dcrwallet is a daemon handling Decred wallet functionality. All interaction with the wallet is performed over RPC.

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. dcrwallet 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, dcrwallet 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.

dcrwallet provides two modes of operation to connect to the Decred network. The first (and default) is to communicate with a single trusted dcrd instance using JSON-RPC. The second is a privacy-preserving Simplified Payment Verification (SPV) mode (enabled with the --spv flag) where the wallet connects either to specified peers (with --spvconnect) or peers discovered from seeders and other peers. Both modes can be switched between with just a restart of the wallet. It is advised to avoid SPV mode for heavily-used wallets which require downloading most blocks regardless.

Not all functionality is available when running in SPV mode. Some of these features may become available in future versions, but only if a consensus vote passes to activate the required changes. Currently, the following features are disabled or unavailable to SPV wallets:

• Voting

• Revoking tickets before expiry

• Determining exact number of live and missed tickets (as opposed to simply unspent).

Wallet clients interact with the wallet using one of two RPC servers:

1. A JSON-RPC server inspired by the Bitcoin Core rpc server

   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 as long as a username and password are provided.

2. A gRPC server

   The gRPC server uses a new API built for dcrwallet, but the API is not stabilized. This server is enabled by default and may be disabled with the config option --nogrpc. If you don't mind applications breaking due to API changes, don't want to deal with issues of the JSON-RPC API, or need notifications for changes to the wallet, this is the RPC server to use. The gRPC server is documented here.

Installing and updating

Binaries (Windows/Linux/macOS)

Binary releases are provided for common operating systems and architectures. Please note that dcrwallet is CLI only. It is included in the CLI app suite. If you would prefer a graphical user interface (GUI) instead, consider downloading the GUI wallet Decrediton.

https://decred.org/downloads/

• How to verify binaries before installing: https://docs.decred.org/advanced/verifying-binaries/
• How to install the CLI Suite: https://docs.decred.org/wallets/cli/cli-installation/
• How to install Decrediton: https://docs.decred.org/wallets/decrediton/decrediton-setup/

Build from source (all platforms)

• Install Go 1.14 or 1.15

  Installation instructions can be found here: https://golang.org/doc/install. Ensure Go was installed properly and is a supported version:

  $ go version
  $ go env GOROOT GOPATH

  NOTE: GOROOT and GOPATH must not be on the same path. It is recommended to add $GOPATH/bin to your PATH according to the Golang.org instructions.

• Build or Update dcrwallet

  Since dcrwallet is a single Go module, it's possible to use a single command to download, build, and install without needing to clone the repo. While outside of any module (go env GOMOD prints an empty newline), run:

  $ GO111MODULE=on go get decred.org/dcrwallet

  An optional version, branch, or tag may be appended following a @ character after the package name. The implicit default is to build @latest, which is the latest semantic version tag. Building @master will build the latest development version. See go help module-get for more details.

  The dcrwallet executable will be installed to $GOPATH/bin. GOPATH defaults to $HOME/go (or %USERPROFILE%\go on Windows).

Getting Started

dcrwallet can connect to the Decred blockchain using either dcrd or by running in Simple Payment Verification (SPV) mode. Commands should be run in cmd.exe or PowerShell on Windows, or any terminal emulator on *nix.

• Run the following command to create a wallet:

dcrwallet --create

• To use dcrwallet in SPV mode:

dcrwallet --spv

dcrwallet will find external full node peers. It will take a few minutes to download the blockchain headers and filters, but it will not download full blocks.

• To use dcrwallet using a localhost dcrd:

You will need to install both dcrd and dcrctl. dcrctl is the client that controls dcrd and dcrwallet via remote procedure call (RPC).

Please follow the instructions in the documentation, beginning with Startup Basics

Running Tests

All tests may be run using the script run_tests.sh. Generally, Decred only supports the current and previous major versions of Go.

./run_tests.sh

Contact

If you have any further questions you can find us at:

https://decred.org/community/

Issue Tracker

The integrated github issue tracker is used for this project.

Documentation

The documentation for dcrwallet is a work-in-progress. It is located in the docs folder.

Additional documentation can be found on docs.decred.org.

License

dcrwallet is licensed under the liberal ISC License.