Licenses

Each node in the content graph can have a license specified to access and reference the underlying content. These licenses are smart contracts that follow the IAuthorization interface:

interface IAuthorization {
    function auth(bytes32 id, address user) external view returns (bool isAuthorized);
}

This interface allows publishers to the content graph to reference content in a collection node and end consumers to access the content that is in an encrypted state at its publicly accessible location. See Distribute Key Management for more.

A publisher may create their own licenses or use common ones.

The licenses allow for complex functionality, such as only allowing reference of an asset if it uses a particular access license.

Example License

The following is an example which is a simple allow list module. This would allow the owner to give the ability to access or reference a node in the content graph to a set of users.

pragma solidity ^0.8.15;
 
import {IContentGraph} from "../IContentGraph.sol";
 
contract AllowListAuthorization {
    address public graph;
    mapping(bytes32 => mapping(address => bool)) allowList;
 
    constructor(address _graph) {
        graph = _graph;
    }
 
    function setState(bytes32 id, address user, bool state) public {
        _checkOwner(bytes32 id);
        allowList[id][user] = state;
    }
 
    function auth(bytes32 id, address user) external view returns (bool isAuthorized) {
        isAuthorized = allowList[id][user];
    }
 
    function _checkOwner(bytes32 id) internal view virtual {
        uint256 token = IContentGraph(graph).getNode(id).token;
        require(IContentGraph(graph).ownerOf(token) == msg.sender, "TokenOwners: caller is not the owner of token id");
    }
}

Storage Overview