Package blocks contains block processing libraries according to the Ethereum beacon chain spec.

Package epoch contains epoch processing libraries according to spec, able to process new balance for validators, justify and finalize new check points, and shuffle validators to different slots and shards.

Package feed defines event feed types for inter-service communication during a beacon node's runtime.

Package helpers contains helper functions outlined in the Ethereum Beacon Chain spec, such as computing committees, randao, rewards/penalties, and more.

Package transition implements the whole state transition function which consists of per slot, per-epoch transitions.

Package validators contains libraries to shuffle validators and retrieve active validator indices from a given slot or an attestation.