DecentralizedWill – A Smart Contract for Time-Locked Inheritance

What's this project about?

DecentralizedWill is an Ethereum smart contract that allows users to securely designate a beneficiary who can claim their ETH if the original owner becomes inactive for a specified period. The contract implements a simple heartbeat mechanism and ensures funds are only released when truly necessary. The purpose of this project is to learn about smart contracts and Solidity programming.

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The contract was deployed on Sepolia testnet. https://sepolia.etherscan.io/address/0x5f212806cdb1a06f490fea2e70a80086870014df

Here is a transaction made with the contract: https://sepolia.etherscan.io/tx/0x243b16f4ed24a4e8b025a012c53ef8a6a9fb761b001a70bf9addf3baca69e8ca

How It Works

• Each user (owner) can set a will by specifying:
  • A beneficiary address (the person who will inherit the ETH)
  • An inactivity period (in seconds)
  • An initial ETH deposit
• The owner must regularly call heartbeat() to signal they are alive.
• If the owner fails to check in and the inactivity period passes, the beneficiary can claim the ETH.
• ETH can be added any time via setWill() or by sending ETH directly.

Features

• Supports multiple owners — each with their own will
• Uses a heartbeat mechanism to reset inactivity countdown
• Beneficiaries can claim only when the owner is inactive
• Allows owners to send more ETH directly to their will.

Functions

setWill(address beneficiary, uint inactivityPeriod) external payable

• Sets or updates the caller’s will.
• Requires ETH deposit (msg.value > 1).
• Updates beneficiary, inactivity period, and last check-in time.

heartbeat() external

• Updates the owner's last check-in timestamp.
• Must be called regularly to keep the will unclaimable.

claim(address owner) external

• Allows a beneficiary to claim the inheritance if:
  • The owner hasn't checked in within the inactivity period
  • They are the registered beneficiary
  • The will hasn’t already been claimed

isClaimable(address owner) external view returns (bool)

• View-only function that returns true if a will is claimable by its beneficiary.