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Contents

• About
• Getting Started
  • Docker
  • Building Zebra
    • Optional Features
• Known Issues
• Future Work
• Documentation
• User support
• Security
• License

About

Zebra is the Zcash Foundation's independent, consensus-compatible implementation of a Zcash node.

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.

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.

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

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:latest

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. Any Zebra release can start depending on new features in the latest stable Rust.

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 and install Zebra:

cargo install --locked zebrad

You can start Zebra by

zebrad start

See the Installing Zebra and Running Zebra sections in the book for more details.

Optional Features

You can also build Zebra with additional Cargo features:

• getblocktemplate-rpcs for mining support
• prometheus for Prometheus metrics
• progress-bar experimental progress bars
• sentry for Sentry monitoring
• elasticsearch for experimental Elasticsearch 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.

Known Issues

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

• Zebra currently gossips and connects to private IP addresses, we want to disable private IPs but provide a config (#3117) in an upcoming release

• 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.

• Rust 1.70 causes crashes during shutdown on macOS x86_64 (#6812). The state cache should stay valid despite the crash.

• 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.

Future Work

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.

User support

For bug reports please open a bug report ticket in the Zebra repository.

Alternatively by chat, Join the Zcash Foundation Discord Server and find the #zebra-support channel.

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.

Some Zebra crates are distributed under the MIT license only, because some of their code was originally from MIT-licensed projects. See each crate's directory for details.