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Using Web3Auth Core Kit tKey SDK in a React Application

webtkeygooglecustom authenticationwhitelabelreactethereumWeb3Auth Team | August 10, 2022

This guide will help you make a react application using Web3Auth Core Kit tKey SDK, covering the basic functionality on how to use it and get started quickly. For a detailed reference, you can refer to the Web3Auth Core Kit tKey SDK Reference.

Live Demo:

Quick Start

npx degit Web3Auth/web3auth-core-kit-examples/tkey-web/intrinsic-flow-examples/tkey-popup-flow-example tkey-demo && cd tkey-demo && npm install && npm start


  • A basic knowledge of JavaScript and React.
  • Ideal to have a knowledge about service workers in React.
  • A Google Developer account to be used as Login provider for Web3Auth Custom Authentication.
  • Create a Web3Auth account on the Web3Auth Dashboard


Setup your Google App

  1. Follow Google’s instructions to set up an OAuth 2.0 app.

  2. Add your application's redirect URI into the "Authorized redirect URIs" field. This is the URL that Google will redirect to after authentication. http://localhost:3000/serviceworker/redirect

    Google OAuth2.0 App Dashboard

  3. Obtain the OAuth Client ID from your App on the Google Developer dashboard

Setup your Web3Auth Dashboard

  • Create a Verifier from the Custom Auth Section of the Web3Auth Developer Dashboard with following configuration:

    • Choose a name of your choice for the verifier identifier. eg. google-core-verifier-ssv
    • Select environment: testnet, mainnet, aqua, or cyan as per your requirement.
    • Select Google from the Login Provider. Google - Login Providers list on Web3Auth Dashboard
    • Paste the Client ID from the Google App(above) to the Client ID field. Google Client ID on Web3Auth Dashboard
    • Click on Create button to create your verifier. It may take up to 10-20 minutes to deploy verifier on testnet. You'll receive an email once it's complete.
  • You will require the verifierName of the newly created verifier.

Setting up your React Project

We will need to use service workers while implementing the tKey SDK to handle the redirect login flow. This can be done by using a progressive react application.

For a new project, get started with the following command:

npx create-react-app tkey-demo --template cra-template-pwa-typescript
cd tkey-demo

For an existing project, add a service worker.

Setting up the service worker

Further, we need to setup the service worker according to our needs of the project, i.e handling the redirect login flow. Service worker basically sits between the frontend application, browser and the network. For the simplicity of this guide, we have added a boilerplate code. The easiest way to do that is as follows

mkdir public/serviceworker
wget -O public/serviceworker/sw.js

For polyfill issues and BigInt issue, please checkout the troubleshooting page.


We will be starting with a 2/2 flow, i.e ShareA: Social Shares and ShareB: Device Share and later will allow users to add more shares of tKey. i.e 2/n

For this project, we will be using @tkey/default that contains all the needed functionalities of the tKey SDK.

npm install --save @tkey/default @tkey/web-storage @tkey/security-questions
  • @tkey/web-storage: This module is used to store the Device Share and used in the 2/2 flow. If you're building for Web, We recommed you to start with this module. i.e 2/2, but there are other modules to achieve the same.
  • @tkey/security-questions: This module is used to create a Share C: Backup Share allowing 2/3 flows. This is what we have chosen for this guide, but there are other ways to achieve the same.

For a detailed reference, you can refer to the Web3Auth Core Kit tKey SDK Reference.


After Installation, the next step to use Web3Auth Core Kit tKey SDK is to Initialize the SDK.


import ThresholdKey from "@tkey/default";
import WebStorageModule from "@tkey/web-storage";
import SecurityQuestionsModule from "@tkey/security-questions";

// Configuration of Service Provider
const customAuthArgs = {
baseUrl: `${window.location.origin}/serviceworker`,
network: "sapphire_mainnet", // based on the verifier network.
// Configuration of Modules
const webStorageModule = new WebStorageModule();
const securityQuestionsModule = new SecurityQuestionsModule();

// Instantiation of tKey
export const tKey = new ThresholdKey({
modules: {
webStorage: webStorageModule,
securityQuestions: securityQuestionsModule,
customAuthArgs: customAuthArgs as any,


import { useEffect } from "react";
import { tKey } from "./tkey";

function App() {
// Init Service Provider inside the useEffect Method
useEffect(() => {
const init = async () => {
// Initialization of Service Provider
try {
await (tKey.serviceProvider as any).init();
} catch (error) {
}, []);

Triggering Login using Service Provider

Once you have initialized the Web3Auth Service Provider, you're ready to trigger the login process. This is a needed step since this will generate a private key which will be needed by the tKey to generate it's share. This is done by calling the triggerLogin() function within the tKey instance's of serviceProvider property.

const triggerLogin = async () => {
try {
// Triggering Login using Service Provider ==> opens the popup
const loginResponse = await (tKey.serviceProvider as any).triggerLogin({
typeOfLogin: "google", // type of login
verifier: "your-web3auth-verifier-name",
clientId: "your-google-client-id",
} catch (error) {

Initialize and Reconstruct tKey

Once you have triggered the login process, you're ready to initialize the tKey. This will generate you a Threshold Key corresponding to your login provider. The below code shows how the device share is added to reconstruct the final private key in the frontend.

const initializeNewKey = async () => {
try {
await triggerLogin(); // Calls the triggerLogin() function above
// Initialization of tKey
await tKey.initialize(); // 1/2 flow
// Gets the deviceShare
try {
await (tKey.modules.webStorage as any).inputShareFromWebStorage(); // 2/2 flow
} catch (error) {
await recoverShare(); // <-- We'll address this later in this guide.

// Checks the requiredShares to reconstruct the tKey,
// starts from 2 by default and each of the above share reduce it by one.
const { requiredShares } = tKey.getKeyDetails();
if (requiredShares <= 0) {
const reconstructedKey = await tKey.reconstructKey();
console.log("Private Key: " + reconstructedKey.privKey.toString("hex"));
// This private key will be used to make blockchain calls.
} catch (error) {
console.error(error, "caught");

Generating a new share with a password

Generate a new share(ShareC: Backup Share) using the security questions module enabling 2/3 flow. One can add more shares from ShareC, but for simplicity, this is what we have chosen for this guide.

Mandatory step

It is mandatory to set up a backup share; upon losing access to device Share, the user will also lose access to their account.

const generateNewShareWithPassword = async () => {
// swal is just a pretty dialog box
swal("Enter password (>10 characters)", {
content: "input" as any,
}).then(async (value) => {
if (value.length > 10) {
await (tKey.modules.securityQuestions as any).generateNewShareWithSecurityQuestions(
"whats your password?",
swal("Success", "Successfully generated new share with password.", "success");
} else {
swal("Error", "Password must be > 10 characters", "error");

Set up Recovery Flow

The Recovery flow generates a new share and adds it into the WebStorageModule. To do so, we take the answer of the Question from the SecurityQuestionsModule setup in the generateNewShareWithPassword() function above.

const recoverShare = async () => {
// swal is just a pretty dialog box
swal("Enter password (>10 characters)", {
content: "input" as any,
}).then(async (value) => {
if (value.length > 10) {
try {
await (tKey.modules.securityQuestions as any).inputShareFromSecurityQuestions(value); // 2/2 flow
const shareStore = await tKey.generateNewShare();
await (tKey.modules.webStorage as any).storeDeviceShare(shareStore.newShareStores[1]);
swal("Success", "Successfully logged you in with the recovery password.", "success");
} catch (error) {
swal("Error", (error as any)?.message.toString(), "error");
} else {
swal("Error", "Password must be >= 11 characters", "error");

Interacting with Blockchain

Once you have generated the private key, you can use it to make blockchain calls. The key generated by tKey is of type secp256k1, which is compatible with EVM-based blockchains like Ethereum, Polygon, and many others that use the same curve. However, you can also convert this key into other curves and utilize it. For example, we have a dedicated package for converting this module to the ed25519 curve for usage in Solana and other blockchains that use this curve.

In addition to that, we have dedicated provider packages for EVM and Solana Blockchain libraries. You can check out their respective documentation here:


You can checkout our Connect Blockchain documentation which has a detailed guide on how to connect to major blockchains out there.

Example code

The code for the application we developed in this guide can be found in the examples repository. Check it out and try running it locally yourself!


Ask us on Web3Auth's Community Support Portal