Savings xDAI (sDAI) - Yield-Bearing ERC-4626 Vault on Gnosis Chain

Overview: Savings xDAI (sDAI) is an ERC-4626 compliant yield-bearing vault on the Gnosis Chain. It enables users to deposit native xDAI or wrapped WXDAI to automatically accrue the MakerDAO (Sky) Savings Rate yield, while maintaining full composability across the Gnosis decentralized finance (DeFi) ecosystem.

Technical Architecture & Yield Mechanism

The sDAI contract on Gnosis Chain is a bridged representation of the Ethereum mainnet sDAI vault. Yield is generated on Ethereum via MakerDAO's DSR (Dai Savings Rate) and bridged to Gnosis Chain via the Omnibridge. The Bridge Receiver contract manages the dripping of this yield into the Gnosis sDAI vault, continuously increasing the exchange rate between sDAI and WXDAI.

Key Smart Contracts (Chain ID: 100)

• sDAI ERC-4626 Vault: 0xaf204776c7245bF4147c2612BF6e5972Ee483701 - The core tokenized vault.
• Vault Adapter / Router: 0xD499b51fcFc66bd31248ef4b28d656d67E591A94 - Periphery contract facilitating atomic native xDAI to sDAI wrapping and unwrapping operations.
• Bridge Receiver: 0x670daeaF0F1a5e336090504C68179670B5059088 - Handles the distribution (dripping) of bridged yield and exposes the vaultAPY() function for calculating current APR.
• WXDAI (Wrapped xDAI): 0xe91D153E0b41518A2Ce8Dd3D7944Fa863463a97d - The underlying reserve asset of the ERC-4626 vault.

Integration & Transaction Workflows

Minting / Depositing

To deposit native xDAI, invoke depositXDAI(address receiver) on the Vault Adapter with the corresponding msg.value. To deposit WXDAI, first execute approve(address spender, uint256 amount) on the WXDAI contract, authorizing the Vault Adapter. Then, invoke deposit(uint256 amount, address receiver) on the Vault Adapter.

Redeeming / Withdrawing

To withdraw into native xDAI, invoke redeemXDAI(uint256 shares, address receiver) or withdrawXDAI(uint256 amount, address receiver) on the Vault Adapter. To withdraw into WXDAI, invoke redeem(uint256 shares, address receiver) or withdraw(uint256 amount, address receiver) on the Vault Adapter. Standard ERC-4626 functions are also fully supported directly on the sDAI vault contract.

Analytics & APY Calculation

Current yield metrics are derived by querying the vaultAPY() view function on the Bridge Receiver contract. The DApp client fetches this value to compute the compounded Annual Percentage Yield (APY) dynamically.