đŸšĒToken Gating

Files can be pushed to the Lighthouse node with encryption using NodeJS to obtain Access Control, similar to the example below.

Project Setup

Step 1: Create a new Node.js application and initialize it:

  • Open your terminal or command prompt.

  • Navigate to the desired directory where you want to create the application.

  • Run the following command to create a new Node.js application

mkdir lighthouse-access-control-app
cd lighthouse-access-control-app
npm init -y

Step 2: Install the required dependencies:

npm install dotenv ethers @lighthouse-web3/sdk

Step 3: Import the necessary dependencies and configure the environment variables in your Node.js application:

Note: In this example, we are using ES6 so we have to save the file as filename.mjs or define "type": "module", in the package.json file.

import * as dotenv from 'dotenv'
import { ethers } from "ethers"
import lighthouse from '@lighthouse-web3/sdk'

const signAuthMessage = async (privateKey) => {
  const provider = new ethers.JsonRpcProvider()
  const signer = new ethers.Wallet(privateKey, provider)
  const messageRequested = (await lighthouse.getAuthMessage(signer.address)).data.message
  const signedMessage = await signer.signMessage(messageRequested)
  return signedMessage

const accessControl = async () => {
  try {
    // CID of encrypted file
    // CID is generated by uploading a file with encryption
    // Only the owner of the file can apply access conditions
    const cid = "Qma7Na9sEdeM6aQeu6bUFW54HktNnW2k8g226VunXBhrn7"
    const publicKey = "0xa3c960b3ba29367ecbcaf1430452c6cd7516f588"
    const privateKey = process.env.PRIVATE_KEY_WALLET1
    // Conditions to add
    const conditions = [
        id: 1,
        chain: "Optimism",
        method: "getBlockNumber",
        standardContractType: "",
        returnValueTest: {
          comparator: ">=",
          value: "13349"

    // Aggregator is what kind of operation to apply to access conditions
    // Suppose there are two conditions then you can apply ([1] and [2]), ([1] or [2]), !([1] and [2]).
    const aggregator = "([1])"

    const signedMessage = await signAuthMessage(privateKey)
      accessCondition(publicKey, cid, signedMessage, conditions, aggregator)
          publicKey: owner's public key
          CID: CID of the file to apply access control on
          signedMessage: message signed by the owner of publicKey
          conditions: access conditions in the specified format
          aggregator: aggregator to apply conditions
    const response = await lighthouse.applyAccessCondition(

    // Display response
  } catch (error) {

const getFileEncryptionKey = async () => {
  try {
    // Get key back after passing access control condition
    const cid = 'YOUR_CID' // Example: "Qma7Na9sEdeM6aQeu6bUFW54HktNnW2k8g226VunXBhrn7";
    const publicKey = 'YOUR_PUBLIC_KEY' // Example: "0x969e19A952A9aeF004e4F711eE481D72A59470B1";
    const privateKey = process.env.PRIVATE_KEY_WALLET2

    const signedMessage = await signAuthMessage(privateKey)
      fetchEncryptionKey(cid, publicKey, signedMessage)
          cid: CID of the file
          publicKey: your public key
          signedMessage: message signed by the owner of the public key
    const key = await lighthouse.fetchEncryptionKey(
  } catch (error) {


Expected Response (for accessControl function):

  data: {
    cid: 'Qma7Na9sEdeM6aQeu6bUFW54HktNnW2k8g226VunXBhrn7',
    status: 'Success'

Expected Response (for getFileEncryptionKey function):

  data: {
    key: '18475nf54a37294f538t4c83ba67e0c5e11fds0fcaa2507cg8539aaff79c5d82'

Step 4: Customize the code:

  • Replace YOUR_CID with the actual CID of the file you want to apply access control on.

  • Replace YOUR_PUBLIC_KEY with your own public key.

  • Update the conditions and aggregator variables according to your access control requirements.

Step 5: Configure the Private Keys:

  • Create a .env file in your project's root directory.

  • Add the following content to the .env file:

  • Replace YOUR_PRIVATE_KEY_WALLET1 with your own private key corresponding to the public key used for Wallet 1 (Can be obtained from the wallet.json file made while creating a wallet).

  • Replace YOUR_PRIVATE_KEY_WALLET2 with your own private key corresponding to the public key used for Wallet 2.

Step 6: Run the Node.js application to upload the file:

  • In the terminal, while in the lighthouse-access-control-app directory, run the following command:

node app.js
  • The response from the access control process will be displayed in the console, indicating the status of the operation.

Note: Ensure that you have the correct CID, private keys, and necessary configurations set before running the application.

With this code, you can apply access control to a file on the Lighthouse node using Node.js.

Supported Chains

Mainnet: Ethereum (ethereum), Polygon (polygon), Solana (solana), Fantom (fantom), Optimism (optimism), BSC (binance chain), AVAX, Fuji Testnet: Mumbai (polygon-testnet), Shardeum_Lib1, Shardeum_Lib2, Calibration, Goerli, BSCTest (binance-testnet), FantomTest, Rinkeby, OptimismGoerli, OptimismKovan Note: Name is not case sensitive.

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