Dapper Sandbox Wallet

This page is an overview of important information you'll need to know to test your Dapper integration.

Download the Sandbox Wallet Chrome Extension

We developed a special version of our wallet for developers to use. The sandbox wallet is a clone of our production wallet extension, but connects to the Rinkeby Testnet.

Download Dapper Sandbox

Important: The sandbox extension connects to the Rinkeby Testnet only.

The following steps are a simple example of how to use the Sandbox extension to test your Dapper (front-end only) integration.

Create an Infura Project

To access Rinkeby to deploy and test your Smart Contracts create a new Infura project: https://infura.io/

Configure Truffle

Run this command from the root of your project to create Truffle configuration files.

npx truffle init && npm install truffle-hdwallet-provider

Be sure you set your new Infura project's secret key as an environment variable. (Obtain the key from your Infura project dashboard).

Add the following config to the newly created truffle.js, assuming you've set process.env.INFURA_SECRET to be your Infura secret key:

const HDWalletProvider = require('truffle-hdwallet-provider');
// DOCS: https://github.com/trufflesuite/truffle-hdwallet-provider

module.exports = {
    networks: {
        rinkeby: {
            provider: () => new HDWalletProvider([process.env.INFURA_SECRET], https://rinkeby.infura.io/v3/[INFURA_PROJECT_ID], 0, 1),
            network_id: 4,
            gas: 5500000,        // Rinkeby has a lower block limit than mainnet
            confirmations: 2,    // # of confs to wait between deployments. (default: 0)
            timeoutBlocks: 200,  // # of blocks before a deployment times out  (minimum/default: 50)
            skipDryRun: true     // Skip dry run before migrations? (default: false for public nets )

You're all set! To access Rinkeby run:

npx truffle console --network rinkeby
Getting ETH from an ETH Faucet

The sandbox extension cannot recieve ETH directly from an Ether faucet. If you need ETH in your Dapper wallet (Dapper pays for your gas, so you may not), you'll need to send ETH to an Ethereum wallet account, and transfer it from that account into Dapper.

If you don't already have an Ethereum account that can recieve ETH from a faucet, create one using the Truffle console, first run:

npx truffle console --network rinkeby

And then:


Which will output something like:

  address: '0x1dDe3e7b9Ad7C75837Bf9BFa63f3A9BDc16B8B39',
  signTransaction: [Function: signTransaction],
  sign: [Function: sign],
  encrypt: [Function: encrypt]

Great! You've created a new Ethereum account. Now you can give theaddress from the above account to an Ether faucet.

After providing this address to a faucet, you'll have to wait a bit for the transfer transaction to complete. To check the balance of your new account use:

Send ETH to your Dapper Wallet

If you haven't already, install the Dapper Sandbox extension and sign up for a Dapper Sandbox account. Once you've installed and signed up for Dapper, you can find your wallet's address at the top of the extension window!

If you got ETH using the instructions above you can run the following command to transfer it into your Dapper wallet:

> web3.eth.sendTransaction({
  from: '0x... The account address created above',
  to: '0x... Your new Dapper address',
  value: '1000000000000000' // 1 ETH

Super, you're funded!

Connecting your dapp to Dapper

There are many ways you can use Web3 in your dapp. Here is one suggested method for using Dapper's web3 provider with an Infura project, to subscribe to events from your contracts.

Important: look at this example carefully. You'll want to make sure that all transactions are carried out via the Dapper provider.

// Transactions will be signed and sent via your Dapper account.
const web3 = new Web3(window.ethereum);
const Contract = new web3.eth.Contract(contractJSON.abi, "0x... Deployed contract address");
const accounts = await window.ethereum.enable();

// Use Infura provider to listen for events from your contract!
const contractListenerWeb3 = new Web3(new Web3.providers.WebsocketProvider("wss://rinkeby.infura.io/ws/v3/[INFURA_PROJECT_ID]"));
contractListenerWeb3.eth.defaultAccount = accounts[0];
const eventSource = new contractListenerWeb3.eth.Contract(contractJSON.abi, "0x... Deployed contract address");

return { web3, accounts, Contract, eventSource }

Monitoring the status of a transaction

To monitor the status of a pending transaction, you'll need to fetch a Transaction Receipt from Dapper. A Transaction Receipt can be used to determine if the transaction succeeded or failed. There are two approaches to getting the Transaction Receipt:

The first and recommended approach is to wait for a Promise from a send call to be resolved with the Transaction Receipt. The receipt will indicate whether the transaction succeeded or failed:

// wait for "send" promise to be resolved with the transaction receipt
const receipt = await web3.eth.sendTransaction({
  from: '0x...',
  to: '0x...',
  value: '1000000000000000'

if (receipt.status === true) {
  console.log('transaction succeeded');
} else {
  console.log('transaction failed');

The second approach is to pass a callback to the send call. The callback will be invoked as soon the transaction is sent to the network. The callback will receive a hash that can be used to poll web3.eth.getTransactionReceipt. You can check the receipt's statusto determine if the transaction is pending, succeeded, or failed.

Important: the callback recieves a hash which is not the transaction hash, so you cannot use it to search for the transaction on a block explorer. When the transaction is confirmed (succeeded or failed), the receipt will contain the actual transaction hash, suitable for use on a block explorer.

// pass a callback to "send" and poll for the the transaction receipt
const callback = (err, hash) => {

  const pollInterval = setInterval(async () => {
    const receipt = await web3.eth.getTransactionReceipt(hash);

    if(!receipt || receipt.status === undefined) {
      console.log('transaction pending');


    if (receipt.status === true) {
      console.log('transaction succeeded');
    } else {
      console.log('transaction failed');
  }, 1000)

  from: '0x...',
  to: '0x...',
  value: '1000000000000000'
}, callback);