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Contents

• Contents
• About
  • Using Zebra
• Release Candidates
• Getting Started
  • Docker
  • Building Zebra
    • Optional Features
  • Network Ports
• Known Issues
• Future Work
• Documentation
• Security
• License

About

Zebra is the Zcash Foundation's independent, consensus-compatible implementation of a Zcash node, currently under development. It can be used to join the Zcash peer-to-peer network, which helps keeping Zcash working by validating and broadcasting transactions, and maintaining the Zcash blockchain state in a distributed manner.

Zcash is a cryptocurrency designed to preserve the user's privacy. If you just want to send and receive Zcash then you don't need to use Zebra directly. You can download a Zcash wallet application which will handle that for you.

Please join us on Discord if you'd like to find out more or get involved!

Using Zebra

You would want to run Zebra if you want to contribute to the Zcash network: the more nodes are run, the more reliable the network will be in terms of speed and resistance to denial of service attacks, for example.

Zebra validates blocks and transactions, but needs extra software to generate them:

• To generate transactions, run Zebra with lightwalletd.
• To generate blocks, enable mining support, and use a mining pool or miner with Zebra's mining JSON-RPCs. Mining support is currently incomplete, experimental, and off by default.

Zebra's network stack is interoperable with zcashd, and Zebra implements all the features required to reach Zcash network consensus, including the validation of all the consensus rules for the NU5 network upgrade. Here are some benefits of Zebra.

Getting Started

You can run Zebra using our Docker image or you can build it manually. Please see the System Requirements section in the Zebra book for system requirements.

Docker

This command will run our latest release, and sync it to the tip:

docker run zfnd/zebra:1.0.0-rc.8

For more information, read our Docker documentation.

Building Zebra

Building Zebra requires Rust, libclang, pkg-config, and a C++ compiler.

Zebra is tested with the latest stable Rust version. Earlier versions are not supported or tested. Note that Zebra's code currently uses features introduced in Rust 1.68, or any later stable release.

Every few weeks, we release a new Zebra version.

Below are quick summaries for installing the dependencies on your machine.

General instructions for installing dependencies

1. Install cargo and rustc.

2. Install Zebra's build dependencies:

   • libclang is a library that might have different names depending on your package manager. Typical names are libclang, libclang-dev, llvm, or llvm-dev.
   • clang or another C++ compiler: g++ (all platforms) or Xcode (macOS).
   • pkg-config

Dependencies on Arch

sudo pacman -S rust clang pkgconf

Note that the package clang includes libclang as well as the C++ compiler.

Once the dependencies are in place, you can build Zebra

cargo install --locked --git https://github.com/ZcashFoundation/zebra --tag v1.0.0-rc.8 zebrad

You can start Zebra by

zebrad start

See the Running Zebra section in the book for more details.

Optional Features

You can also build Zebra with additional Cargo features:

• sentry for Sentry monitoring
• journald for journald logging
• prometheus for Prometheus metrics
• getblocktemplate-rpcs for mining support

You can combine multiple features by listing them as parameters of the --features flag:

cargo install --features="<feature1> <feature2> ..." ...

Our full list of experimental and developer features is in the API documentation.

Some debugging and monitoring features are disabled in release builds to increase performance.

Network Ports

Zebra uses the following inbound and outbound TCP ports:

• 8233 on Mainnet
• 18233 on Testnet

Please see the Network Requirements section of the Zebra book for more details.

Known Issues

There are a few bugs in Zebra that we're still working on fixing:

• If Zebra fails downloading the Zcash parameters, use the Zcash parameters download script instead.

• Block download and verification sometimes times out during Zebra's initial sync #5709. The full sync still finishes reasonably quickly.

• No Windows support #3801. We used to test with Windows Server 2019, but not any more; see the issue for details.

• Experimental Tor support is disabled until Zebra upgrades to the latest arti-client. This happened due to a Rust dependency conflict, which could only be resolved by arti upgrading to a version of x25519-dalek with the dependency fix.

• Output of help, --help flag, and usage of invalid commands or options are inconsistent #5502. See the issue for details.

Future Work

The Zebra team is currently working towards an audited stable release.

We will continue to add new features as part of future network upgrades, and in response to community feedback.

Documentation

The Zebra website contains user documentation, such as how to run or configure Zebra, set up metrics integrations, etc., as well as developer documentation, such as design documents. We also render API documentation for the external API of our crates, as well as internal documentation for private APIs.

Security

Zebra has a responsible disclosure policy, which we encourage security researchers to follow.

License

Zebra is distributed under the terms of both the MIT license and the Apache License (Version 2.0).

See LICENSE-APACHE and LICENSE-MIT.