Contract Ownership & Access Control

Every dApp needs someone holding the keys to the control room. That’s the owner.​
You usually set the owner once, in the constructor, when the contract is deployed:

address private contractOwner;

constructor() {
    contractOwner = msg.sender;
}

address private contractOwner;

constructor() {
    contractOwner = msg.sender;
}

address private contractOwner;

constructor() {
    contractOwner = msg.sender;
}

Here, msg.sender is the address that deployed the contract. On VeChain, this might be your deployment script or VeWorld.​

To guard sensitive functions, you wrap them with a modifier like onlyOwner:

modifier onlyOwner() {
    require(msg.sender == contractOwner, "Only owner can call this");
    _;
}

function addUser(...) public onlyOwner {
    // admin-only logic
}

modifier onlyOwner() {
    require(msg.sender == contractOwner, "Only owner can call this");
    _;
}

function addUser(...) public onlyOwner {
    // admin-only logic
}

modifier onlyOwner() {
    require(msg.sender == contractOwner, "Only owner can call this");
    _;
}

function addUser(...) public onlyOwner {
    // admin-only logic
}

Think of a modifier like a reusable gateway: the code inside runs before the main function body.​

In the WorkshopContract, this pattern controls who can manage participants and critical settings, while regular users only call safe endpoints like checkIn.​

Awesome! You now understand why ownership separation is mandatory even when VeChain gas is low and fees can be delegated.