The Ethereum Proof-of-Stake Consensus Specifications repository is the definitive source for the technical guidelines governing Ethereum’s transition and ongoing use of a proof-of-stake (PoS) consensus mechanism. This repository contains the core specifications for PoS client implementation, which are organized into features and aligned with sequential network upgrades such as Phase 0, Altair, and Bellatrix. Each upgrade involves critical network changes, including beacon chain modifications, light client protocol enhancements, and validator updates. The repository fosters community collaboration, where design proposals and changes to the specifications can be discussed through issues and integrated via pull requests. Accompanying documentation provides detailed insights into serialization formats, merkle proofs, client APIs, and metrics, aligning with design goals for minimal complexity, resilience to network partitions, and high participation of validators. Additionally, resources for spec contributors include executable specifications and test guides to ensure adherence and maintain the robustness of the Ethereum network through its evolutionary PoS framework.