LuckYeld Protocol

LuckYeld is a decentralized savings protocol that implements a no-loss prize-linked reward system using blockchain-based smart contracts. The protocol allows users to deposit stablecoins into a pooled vault where the capital is allocated to yield-generating strategies backed by tokenized real-world assets. Instead of distributing the generated yield proportionally as interest, the protocol periodically distributes the yield through randomized prize draws among participants.
The system is designed so that users do not risk their deposited capital. Participants deposit funds into a tokenized vault and receive vault shares representing their proportional claim over the pooled assets. These deposits remain fully redeemable at any time, allowing users to withdraw their principal while still being eligible for prize draws as long as their funds remain deposited in the vault.
The yield generated by the pooled capital is periodically transferred to a prize pool smart contract. This prize pool allocates the yield according to predefined protocol rules, typically distributing the majority of the yield to randomly selected winners while reserving smaller portions for protocol sustainability and liquidity incentives. The selection of winners is executed on-chain using verifiable randomness to ensure fairness, transparency, and resistance to manipulation.
The protocol architecture relies on automated smart contracts that manage deposits, yield allocation, prize distribution, and vault accounting without the need for centralized intermediaries. Randomness used for prize selection is generated using cryptographic oracle infrastructure to ensure that the outcome of each draw is provably fair and publicly verifiable. Similar decentralized lottery mechanisms have been implemented in blockchain systems using oracle-based randomness solutions to guarantee transparent winner selection.
From a technical perspective, the system combines several blockchain standards and components:

• Tokenized vault architecture (ERC-4626) to manage deposits and accounting of user shares.
• Yield strategies backed by tokenized real-world assets, such as short-term U.S. Treasury exposure.
• Automated smart contracts to execute periodic prize distributions.
• Verifiable on-chain randomness to fairly select winners.

This structure is conceptually similar to decentralized “no-loss lotteries,” where participants deposit funds that are temporarily allocated to yield-generating strategies and the generated yield is distributed as prizes, while the original deposits remain withdrawable.
By combining decentralized finance infrastructure with real-world asset yield sources, the protocol aims to create a savings mechanism that incentivizes participation through probabilistic rewards while maintaining principal protection for depositors.

It is built as a three-contract smart contract architecture around a no-loss savings flow: a user-facing ERC-4626 vault, a yield strategy connected to Ondo’s USDY, and a prize engine that uses Chainlink VRF for winner selection. The repo describes the system as an MVP built with Foundry, written in Solidity ^0.8.20, and using OpenZeppelin plus Chainlink libraries.

More concretely:

• PrizeVault.sol is the main entry point for users. Depositors send USDC into an ERC-4626 vault and receive shares, with the README stating the principal is backed 1:1 and remains withdrawable.
• OndoStrategy.sol moves vault liquidity into Ondo Finance’s USDY to earn yield linked to short-term U.S. Treasuries / RWAs. On a periodic basis, the strategy measures portfolio growth, protects the original principal, and sends only the pure yield back in USDC.
• PrizePool.sol receives that harvested yield and splits it automatically: 80% to the weekly prize pool, 10% to protocol treasury, and 10% to LP incentives. It then requests randomness from Chainlink VRF v2 to select a winner among active depositors, and the winner claims through a pull-based claimPrize flow.

So, in one sentence: the project is built as an ERC-4626 USDC vault that routes deposits into an Ondo USDY yield strategy, harvests only the generated yield, and distributes that yield through a Chainlink-VRF-powered prize pool while keeping user principal redeemable at all times.