Zeam is a production-grade implementation (work-in-progress) of the Beam Chain — a ZK-based Ethereum Consensus Protocol unveiled at Devcon 7 Bangkok (November 2024). Beam Chain is designed to upgrade the current Beacon Chain by massively scaling and decentralizing Ethereum consensus through provable, ZK-VM-backed state transitions.
- Overview
- Beam Chain
- Client Architecture
- Package Structure
- ZK Prover Support
- Libraries & Ecosystem
- Build Instructions
- Running a Local Devnet
- Testing
- Community & Contributions
- Reporting Issues
Beam Chain introduces several disruptive improvements to Ethereum consensus that are difficult to implement incrementally on the current Beacon Chain:
- ZK-provable state transitions — every state transition can be proven and verified by a ZK-VM
- Quantum-resistant cryptography — hash-based signatures (XMSS) replacing BLS
- Decentralized consensus — designed to scale and decentralize at the protocol level
Zeam translates these specs into a production-grade Zig client, actively contributing to the development of the Beam protocol alongside other client teams.
Zeam's architecture closely mirrors the Beacon Chain client structure, adapted for Beam's ZK-centric design. The client is built modularly, with each concern separated into its own package.
The team is currently building and validating foundational POCs and libraries before composing them into a full client:
| Area | Status |
|---|---|
| ZK-VM state transition proving | Active POC |
| libp2p networking (Zig ↔ Rust) | POC complete |
| SSZ serialization | Library available |
| Hash-based signatures (XMSS) | In development |
| Snappy compression | Library available |
| Full client integration | Upcoming |
Refer to ZEAM POC for detailed documentation on the current POC scope and design.
The pkgs/ directory contains the modular components of the Zeam client:
| Package | Description |
|---|---|
pkgs/state-transition |
Core state transition logic (Zig) |
pkgs/state-transition-runtime |
RISC-V binary executed inside ZK-VMs |
pkgs/state-proving-manager |
Orchestrates ZK proving and verification |
pkgs/node |
Main node lifecycle and coordination |
pkgs/network |
libp2p-based P2P networking |
pkgs/api |
HTTP API layer |
pkgs/cli |
Command-line interface |
pkgs/database |
Persistent storage (RocksDB) |
pkgs/types |
Shared Beam/Zeam data types |
pkgs/spectest |
Spec test framework |
pkgs/metrics |
Prometheus-compatible metrics |
pkgs/xmss |
Hash-based signature scheme |
pkgs/key-manager |
Key management utilities |
pkgs/params |
Protocol parameters |
pkgs/configs |
Node configuration |
pkgs/utils |
Shared utilities |
pkgs/tools |
Developer tooling |
Zeam supports multiple ZK-VMs for state transition proving:
| Prover | Status | Notes |
|---|---|---|
| risc0 v3.0.3 | Supported | Requires external toolchain |
| OpenVM | Supported | Self-contained, no toolchain needed |
Zeam is developing and contributing to the Zig Ethereum ecosystem. These libraries are used in and alongside the client:
| Library | Description |
|---|---|
| ssz.zig | SSZ serialization with configurable hash function |
| zig-snappy / snappyframesz | Snappy compression |
| zig-libp2p-pocs | Zig ↔ Rust libp2p interop |
| hash-sigz | Hash-based signature schemes |
| zeam-runtime | ZK-VM runtime POC |
If you are developing a library in the Zig ecosystem that could benefit Zeam, please reach out via Telegram.
- Zig
0.15.2 - Rust
1.85+(required for ZK-VM Rust bindings) - risc0 toolchain (only if using risc0 prover):
rzup install r0vm 3.0.3 - OpenVM is self-contained — no additional toolchain required
Build all transition functions and the full client:
zig build -Doptimize=ReleaseFastTo include the git version in the binary:
zig build -Doptimize=ReleaseFast -Dgit_version="$(git rev-parse --short HEAD)"zig build -Doptimize=ReleaseFast install run -- proveDocker images are built in CI using Dockerfile.prebuilt, which packages pre-built binaries. This avoids intermittent failures caused by a Zig HTTP connection pool bug when building inside Docker.
Build a Docker image locally:
# Build zeam natively first
zig build -Doptimize=ReleaseFast -Dgit_version="$(git rev-parse --short HEAD)"
# Then create Docker image with pre-built binary
docker build -f Dockerfile.prebuilt -t zeam:local .Build with OCI labels for registry publishing:
docker build -f Dockerfile.prebuilt \
--build-arg GIT_COMMIT=$(git rev-parse HEAD) \
--build-arg GIT_BRANCH=$(git rev-parse --abbrev-ref HEAD) \
-t blockblaz/zeam:latest .To run a local devnet with multiple nodes for testing and development, see the Local Devnet Setup Guide, which covers a 2-node setup with finalization.
Alternatively, use the lean-quickstart submodule:
git submodule update --init lean-quickstartThis provides a handy CLI tool to spin up two nodes for local interop.
Zeam supports checkpoint sync for faster initial synchronization. Start a node from a trusted finalized checkpoint state using the --checkpoint-sync-url flag. See the Local Devnet Setup Guide for full documentation.
| Scenario | Guide |
|---|---|
| Test blocks by root (parent sync) | parent-sync.md |
| Test checkpoint sync | checkpoint-sync.md |
| Spec test framework | spec-test-framework.md |
Join the conversation around Beam Protocol and Zeam client:
Zeam welcomes open-source contributions that meaningfully advance the client. Watch for announcements in the community or reach out directly via Telegram.
Open a GitHub issue or reach out via the Telegram community group.