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Welot : No-Loss lottery

welot is a no‑loss savings lottery. Your deposit stays withdrawable any time. The prize pool comes from generated yield from the deposits.

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Tech Stack

Ethers
Solidity
Web3
React
Next

Description

WeLot - No-Loss Lottery Protocol

WeLot is a decentralized, no-loss weekly lottery game built on the Mantle Network. It allows users to deposit tokens into a assigned savings pool where they retain their principal while having a chance to win prizes generated from the collective yield of all the remaining pools.

How It Works:

  • No-Loss Mechanism: Users deposit supported ERC-20 tokens into a vault. These deposits are routed to ERC-4626 compliant yield sources (such as Lendle). The principal remains safe and withdrawable.

  • Prize Generation: Instead of paying for tickets, the interest (yield) generated by the pooled assets over time becomes the prize pool.

  • Fair Winner Selection: The protocol uses PYTH Entropy V2 for randomness to ensure fair selection. Winners pool is chosen via a time-weighted algorithm, meaning the likelihood of winning is proportional to the deposit size and duration.

  • Epochs: The game operates in epochs (e.g., weekly). At the end of an epoch, the yield is harvested, a winner is selected, and the prize is distributed.

Key Technical Features:

  • Contracts: Built using Foundry, with a core WelotVault contract managing deposits, yield routing, and prize accounting.

  • Frontend: A Next.js application for users to interact with the protocol.

  • Automation: Supports keeper workflows (e.g., any Offchain or Onchai) to handle epoch closing and randomness requests.

Links

Progress During Hackathon

1. Smart Contract Architecture (Completed) Core Vault Logic: Developed the WelotVault contract which handles user deposits, pool assignments, and prize accounting. Yield Integration: Successfully integrated with mock Lendle (Mantle's leading lending protocol) using an ERC-4626 adapter (LendleYieldVault) to generate real yield from user deposits. Randomness: Implemented fair winner selection using pyth Entropy V2 for verifiable on-chain randomness. Epoch System: Built a robust epoch lifecycle (Open → Closed → Randomness → Finalize) that automates weekly draws. 2. Frontend Application (Completed) Built a Next.js web interface that allows users to: Connect wallets. Deposit tokens into the savings pool. View their current position and potential winnings. Withdraw principal and claim prizes. Configured the UI to interact seamlessly with the deployed Mantle contracts. 3. Automation & Keepers (Implemented) Developed Keeper scripts (frontend/scripts/keeper.mjs) to automate critical protocol functions, such as closing epochs and requesting randomness, ensuring the lottery runs autonomously without manual intervention. 4. Testing & Deployment (In Progress) Local Testing: Created a comprehensive local testing environment using Foundry (DeployLocal.s.sol) with mock yield sources and faucets. Mantle Testnet: Reached the testnet deployment stage (evidenced by TESTNET_TESTING.md), verifying the protocol's functionality in a live environment. Scripts: Wrote deployment scripts (DeployMantle.s.sol) to streamline the launch on Mantle Sepolia and Mainnet.
Team Leader
SSatya Pradhan
Project Link
Sector
DeFiGaming