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Client Implementations

Fukuii is Ethereum Classic's primary client, built natively for ETC. Core-Geth, a go-ethereum derivative, is maintained alongside it so the network never depends on a single codebase. ETC plugins add Ethereum Classic support into existing Ethereum clients, widening execution-layer reach without adding another codebase to maintain.

Fukuii

PrimaryEnterpriseETC-nativeScala

Ethereum Classic's first native client — an EVM execution client in Scala 3 LTS on Pekko Typed Actors, running on the JVM. One binary runs several networks at once in one JVM process, each isolated with its own state, its own metrics registry, and its own configuration; a further network is configuration, not a new client.

Features

  • Several networks at once in one JVM process, each fully isolated
  • Consensus selected per deployment: native Proof-of-Work for ETC mainnet and Mordor
  • Proof-of-Stake with a built-in consensus layer, or an external client over the Engine API V1–V4
  • SNAP, fast, and regular sync; JSON-RPC, GraphQL, and an MCP server exposing node state to AI agents
  • JVM-native end to end for institutions already on the JVM: JFR, async-profiler, JMX and heap dumps work as on any JVM process, with no foreign-language bridge
  • Prometheus metrics, Grafana dashboards, and liveness and readiness endpoints in the binary
  • Apache 2.0, with Cosign-signed build provenance and a CycloneDX SBOM on release artifacts
WindowsmacOSLinuxDocker

Quick Start

Install

docker pull ghcr.io/fukuii-project/fukuii-cli:latest

Configuration

Select the network with --network=etc for ETC mainnet or --network=mordor for the ETC testnet. Requires a current JDK LTS (25); the Docker image bundles one.

Core-Geth

MaintainedGo

A go-ethereum derivative maintained for Ethereum Classic, carried through the Olympia upgrade for network continuity. etclabscore/core-geth v1.12.x was unmaintained June 2024–March 2026 (21 months), accumulating six unpatched CVEs that were actively exploited against ETC mainnet bootnodes. All CVEs patched by White B0x at ethereumclassic/core-geth, pending release as v1.13.0.

Maintenance mode since Dec 2024 · 6 CVEs patched at ethereumclassic/core-geth, v1.13.0 pending · Upgrade to v1.12.22 now · Migrate to FukuiiSecurity audit →

Features

  • Full and light sync modes
  • JSON-RPC and WebSocket APIs
  • EVM tracing and debugging
  • Built-in mining support
  • MEV-free transaction ordering
WindowsmacOSLinuxDocker

Quick Start

Install

docker pull ghcr.io/ethereumclassic/core-geth:latest

Configuration

Use --classic flag for ETC mainnet, --mordor for testnet

ETC Compatibility Plugins

A plugin adds Ethereum Classic chain support into an existing Ethereum client’s execution layer rather than maintaining a full fork. It is not a client implementation and carries no mining or Proof-of-Work consensus, so plugins serve non-mining infrastructure: exchanges, RPC providers, block explorers, indexers, and archive nodes on whichever execution environment an operator already runs.

Besu

JavaPlugin

A plugin that adds ETC support into the Besu codebase, an enterprise-grade Java client for institutional infrastructure.

Erigon

GoPlugin

A plugin that adds ETC support into the Erigon codebase, an archive-optimized client built for minimal disk usage and fast historical queries.

Ethrex

RustPlugin

A plugin that adds ETC support into the Ethrex codebase, a minimalist Rust client.

Go-Ethereum

GoPlugin

A plugin that adds ETC support into the Go-Ethereum codebase, the most widely deployed EVM client.

Nethermind

C#Plugin

A plugin that adds ETC support into the Nethermind codebase, a high-performance .NET client with native Windows deployment.

Reth

RustPlugin

A plugin that adds ETC support into the Reth codebase, a modular, performance-focused Rust client.