Lighthouse

Overview.

Lighthouse is one of five production consensus clients on Ethereum. It implements the proof-of-stake protocol, including attestation processing, fork choice, finality, validator duties, and the Engine API that connects to an execution client.

It runs in production on home stakers, professional staking operations, exchanges, and institutional infrastructure. More than half of the Ethereum network runs on Lighthouse, making it one of the most widely deployed implementations.

Why we built it.

Lighthouse started in 2018 as a research project before the Beacon Chain spec was finalised. As the transition to proof of stake came into focus, the project shifted from research to production engineering. Lighthouse shipped at the December 2020 Beacon Chain genesis and has been continuously maintained since.

Lighthouse has been funded via grants from the Ethereum Foundation. The project remains open source under Apache 2.0 / MIT.

Status.

Lighthouse has shipped through every Ethereum hard fork since the Beacon Chain launched, including Altair, Bellatrix (the Merge), Capella, Deneb, and Pectra. The team has handled coordinated client upgrades and live network conditions throughout.

See clientdiversity.org for independent measurement of consensus client distribution across the network.

How it informs audits.

Building and operating a consensus client gives us implementation experience that audit-only firms usually do not have. When we audit blockchain protocols, the engineers reading the spec have also shipped client code, debugged it under live network conditions, and rolled forward through coordinated client upgrades.

For application-layer audits, consensus-client experience helps at the boundary. Validator-related smart contracts for staking, slashing, restaking, and MEV-Boost adapters compose with consensus-layer behaviour, and reviewers who understand both sides catch issues that contract-only review can miss.