Besu

Besu is an open source Ethereum client developed under the Apache 2.0 license and implemented in Java. It is designed to run on both public Ethereum networks, including Mainnet and testnets like Holesky, Hoodi, Ephemery, and Sepolia, as well as private networks tailored for enterprise use cases requiring secure and high-performance transaction processing. Besu provides a command line interface and a JSON-RPC API accessible over HTTP and WebSocket, supporting common Ethereum JSON-RPC methods such as eth, net, web3, debug, and miner. It also supports Pub/Sub messaging for event subscriptions.

The client integrates with popular Ethereum development tools like Hardhat, Remix, and web3j, facilitating smart contract and decentralized application (dapp) development, deployment, and node operation. Besu does not handle key management internally; instead, it integrates with Web3Signer to manage keystores and sign transactions securely. This separation enhances security and modularity for enterprise deployments.

Besu stands out by offering a Java-based Ethereum client option that supports both public and permissioned private networks, making it suitable for enterprises and developers who require flexibility and compliance features. It includes advanced features such as performance profiling with Async Profiler, detailed EVM execution tracing, and comprehensive debugging tools. The client is actively maintained by the Hyperledger community, with extensive documentation, a Discord channel for support, and a transparent development roadmap.

Getting started with Besu involves downloading the binary or building from source, configuring the client for the desired network type, and using the JSON-RPC API or CLI for node management. Developers can contribute to the project or extend its functionality through the open-source codebase and community resources.