Document Registry - Infura API (accessed through Web3.js)

Cert.sol

pragma solidity ^0.4.18;

contract Cert {
  mapping (string => bool) private certificateHashes;
  address contractOwner = msg.sender;

  function add(string hash) public {
    require (msg.sender == contractOwner);
    certificateHashes[hash] = true;
  }

  function verify(string hash) view public returns (bool) {
    return certificateHashes[hash];
  }
}

Links.txt

https://ropsten.etherscan.io/address/0x184b1f4bccc68377ea2811e1e6268ded10b4d199

web3-infura-example.js

let Web3 = require("web3");
let web3 = new Web3("https://ropsten.infura.io/z0NBZ7w5VCWFt9qjFUVk");

//web3.eth.getBalance('0x5981768670925f461211b54212ed8bb95e9a3ba2').then(console.log)

const contractAddress = '0x184b1f4bccc68377ea2811e1e6268ded10b4d199';

const contractABI = [
	{
		"constant": true,
		"inputs": [
			{
				"name": "hash",
				"type": "string"
			}
		],
		"name": "verify",
		"outputs": [
			{
				"name": "",
				"type": "bool"
			}
		],
		"payable": false,
		"stateMutability": "view",
		"type": "function"
	},
	{
		"constant": false,
		"inputs": [
			{
				"name": "hash",
				"type": "string"
			}
		],
		"name": "add",
		"outputs": [],
		"payable": false,
		"stateMutability": "nonpayable",
		"type": "function"
	}
]

let contract = new web3.eth.Contract(contractABI, contractAddress);

contract.methods.verify("abc").call().then(retval => {
	console.log("Document `abc` is valid? " + retval);
});

contract.methods.verify("pesho").call().then(retval => {
	console.log("Document `pesho` is valid? " + retval);
})