Viewers

Viewers are addresses that have permission to decrypt the data associated with a handle. Managing viewers is essential for controlling who can view the decrypted data.

INFO

An account which is a viewer for a handle can get the decrypted value of a handle with the decrypt method of the SDK.

Checking Viewers

The Nox protocol smart contract provides a function to check if a specific address is a viewer for a given handle:

function isViewer(bytes32 handle, address account) external view returns (bool);

isViewer ABI:

[
  {
    "inputs": [
      {
        "internalType": "bytes32",
        "name": "handle",
        "type": "bytes32"
      },
      {
        "internalType": "address",
        "name": "viewer",
        "type": "address"
      }
    ],
    "name": "isViewer",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  }
]

ethers

const noxContract = new Contract(
  NOX_CONTRACT_ADDRESS,
  NOX_CONTRACT_ABI,
  provider
);
const isViewer: boolean = await noxContract.isViewer(handle, account);

viem

const isViewer = await publicClient.readContract({
  address: NOX_CONTRACT_ADDRESS,
  abi: NOX_CONTRACT_ABI,
  functionName: 'isViewer',
  args: [handle, viewerAddress],
});

Adding Viewers

The Nox protocol smart contract provides a function for admins to add a specific address as a viewer for a given handle:

INFO

Only allowed admins can add viewers. (see Manage Admins guide for more details on admins management).

WARNING

Once added, a viewer cannot be removed.

function addViewer(bytes32 handle, address account) external;

addViewer ABI:

[
  {
    "inputs": [
      {
        "internalType": "bytes32",
        "name": "handle",
        "type": "bytes32"
      },
      {
        "internalType": "address",
        "name": "viewer",
        "type": "address"
      }
    ],
    "name": "addViewer",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  }
]

ethers

const noxContract = new Contract(
  NOX_CONTRACT_ADDRESS,
  NOX_CONTRACT_ABI,
  signer
);
const tx = await noxContract.addViewer(handle, viewerAddress);
await tx.wait();

viem

const [userAddress] = await walletClient.getAddresses();

await walletClient.writeContract({
  account: userAddress,
  chain: CHAIN,
  address: NOX_CONTRACT_ADDRESS,
  abi: NOX_CONTRACT_ABI,
  functionName: 'addViewer',
  args: [handle, viewerAddress],
});