Lido V3 Architecture

Lido V3 Smart Contracts

Here are the main smart-contracts employed in Lido V3:

Smart Contract	Role / Purpose
Staking Vault	Represents an isolated staking environment: holds ETH, submits validator deposits and trigger validator withdrawals. Each vault has an owner and is tied to a chosen node operator.
Vault Hub	Central registry and coordination layer between Vaults and the main Lido protocol. Manages vault metadata, enforces collateralization constraints, and handles minting/burning of stETH against vault collateral.
Lazy Oracle	Responsible for vault-specific reporting: periodically aggregates validator and vault data (rewards, slashes, value changes) and submits them to the Vault Hub. It bridges information on the Beacon Chain to Ethereum Mainnet.
Vault Factory	Factory contract used to deploy verified/stable vault instances. Only vaults deployed via VaultFactory are recognized by Lido Core and can be connected to VaultHub — this ensures security and standardization.
Predeposit Guarantee (PDG)	A security guard for validator deposits: ensures that validator activations are properly backed by ETH, mitigating deposit front-running or invalid validator credential risks. [HackMD]
Dashboard	Provides a user-friendly interface layer for vault owners: role-based permissions, fee accounting, vault operations (deposit, mint, rebalance etc.). While optional, the Dashboard brings significant UX improvements.
Operator Grid	Maintains the registry of node operators, enforces per-operator & per-tier limits for stETH minting from vaults, and manages risk parameters (reserve ratios, share limits, rebalance thresholds).

How These Pieces Fit Together

Each stVault is deployed (via the Vault Factory), and once funded and properly initialized, can be connected to Vault Hub.
The Vault Hub serves as the coordination center between stVaults and Lido: it recognizes stVaults, tracks their total value, and ensures any minted stETH is safely backed by locked ETH + reserves enforced through OperatorGrid parameters (reserve ratio, share limits, etc.).
As validators under a vault accumulate rewards or suffer penalties, periodic reports are submitted via Lazy Oracle. These updates adjust the vault’s total value, locked collateral, and obligations (mint liability, fees, etc.) accordingly.
The reserve and health-check logic ensures that vaults remain sufficiently collateralized. If a vault becomes undercollateralized (e.g. due to slashing), it may be forced into rebalance or redemption, ensuring the overall stETH solvency.
To improve the user experience, the Dashboard contract provides owners a unified point of access to operate and manage permissions to stVaults.