React
Follow this quickstart tutorial to add authentication to your React application
Authgear helps you add user logins to your React apps. It provides prebuilt login page and user settings page that accelerate the development.
Follow this 15 minutes tutorial to create a simple app using React with Authgear SDK.
🕐
Table of Content
After that, we will need to create an Application in the Project Portal.
- 1.Go to Applications on the left menu bar.
- 2.Click ⊕Add Application in the top tool bar.
- 3.Input the name of your application, e.g. "MyAwesomeApp".
- 4.Select Single Page Application as the application type
- 5.Click "Save" to create the application
The Redirect URI is a URL in you application where the user will be redirected to after login with Authgear. In this path, make a finish authentication call to complete the login process.
For this tutorial, add
http://localhost:4000/auth-redirect
to Authorize Redirect URIs.The Post Logout Redirect URI is the URL users will be redirected after they have logged out. The URL must be whitelisted.
For this tutorial, add
http://localhost:4000/
to Post Logout Redirect URIs.Save the configuration before next steps.

Configure Authorized Redirect URIs and Post Logout Redirect URIs.
Here are some recommended steps to scaffold a React project. You can skip this part if you are adding Authgear to an existing project. See install-authgear-sdk-to-the-project in the next section.
Create the project folder and install the dependencies. We will use
parcel
as the build tool and the react-router-dom
, react
, and react-dom
packages. Also, we will use TypeScript in this tutorial. # Create a new folder for your project
mkdir my-app
# Move into the project directory
cd my-app
# Create source folder
mkdir src
# Create a brand new package.json file
npm init -y
# Install parcel
npm install --save-dev --save-exact parcel
# Install react, react-dom and react router
npm install --save-exact react react-dom react-router-dom
# Install TypeScript and related types
npm install --save-dev --save-exact typescript @types/react @types/react-dom @types/react-router-dom
In the
package.json
file, add these two lines to the script
section"start": "parcel serve --port 4000 --no-cache ./src/index.html",
"build": "parcel build --no-cache ./src/index.html"
The
start
script run the app in development mode on port 4000. The build
script build the app for production to the dist/
folder.In
src/
, create a new file called index.html
for parcel to bundle the app: src/index.html
:<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<title>Authgear React Tutorial Demo App</title>
</head>
<body>
<div id="react-app-root"></div>
<script type="module" src="./index.tsx"></script>
</body>
</html>
Create a new file called
App.tsx
with simply showing Hello World
in the screen: // src/App.tsx
import React from "react";
const App: React.FC = () => {
return <div>Hello World</div>;
};
export default App;
Create a new file called
index.tsx
as the entry point of the application.// src/index.tsx
import React from "react";
import { createRoot } from "react-dom/client";
import App from "./App";
async function init() {
try {
// initialization code
} finally {
createRoot(document.getElementById("react-app-root")!).render(<App />);
}
}
init().catch((e) => {
// Error handling
console.error(e)
});
The file structure in your project is now:
my-app
├── node_modules
│ └── (...)
├── package-lock.json
├── package.json
└── src
├── App.tsx
├── index.html
└── index.tsx
Run
npm start
now to run the project and you will see "Hello World" on http://localhost:4000
.Run the following command within your React project directory to install the Authgear Web SDK
npm install --save --save-exact @authgear/web
In
src/index.tsx
, import authgear
and call the configure
function to initialize an Authgear instance on application loads.// src/index.tsx
import React from "react";
import { createRoot } from "react-dom/client";
import App from "./App";
import authgear from "@authgear/web";
async function init() {
try {
// configure Authgear container instance
await authgear.configure({
endpoint: "<your_app_endpoint>",
clientID: "<your_client_id>",
sessionType: "refresh_token",
});
} finally {
createRoot(document.getElementById("react-app-root")!).render(<App />);
}
}
init().catch((e) => {
// Error handling
console.error(e)
});
The Authgear container instance takes
endpoint
and clientID
as parameters. They can be obtained from the application page created in Setup Application in Authgear.It is recommend to render the app after
configure()
resolves. So by the time the app is rendered, Authgear is ready to use. Run
npm start
now and you should see a page with "Hello World" and no error message in the console if Authgear SDK is configured successfullySince we want to reference the logged in state in anywhere of the app, let's put the state in a context provider with
UserProvider.tsx
in the /src/context
folder. In
UserProvider.tsx
, it will have a isLoggedIn
boolean and a setIsLoggedIn
function. The is LoggedIn
boolean state can be auto updated using the onSessionStateChange
callback. This callback can be stored in delegate
which is in the local SDK container. // src/context/UserProvider.tsx
import React, { createContext, useEffect, useState, useMemo } from "react";
import authgear from "@authgear/web";
interface UserContextValue {
isLoggedIn: boolean;
}
export const UserContext = createContext<UserContextValue>({
isLoggedIn: false,
});
interface UserContextProviderProps {
children: React.ReactNode;
}
const UserContextProvider: React.FC<UserContextProviderProps> = ({
children,
}) => {
// By default the user is not logged in
const [isLoggedIn, setIsLoggedIn] = useState<boolean>(false);
useEffect(() => {
// When the sessionState changed, logged in state will also be changed
authgear.delegate = {
onSessionStateChange: (container) => {
// sessionState is now up to date
// Value of sessionState can be "NO_SESSION" or "AUTHENTICATED"
const sessionState = container.sessionState;
if (sessionState === "AUTHENTICATED") {
setIsLoggedIn(true);
} else {
setIsLoggedIn(false);
}
},
};
}, [setIsLoggedIn]);
const contextValue = useMemo<UserContextValue>(() => {
return {
isLoggedIn,
};
}, [isLoggedIn]);
return (
<UserContext.Provider value={contextValue}>{children}</UserContext.Provider>
);
};
export default UserContextProvider;
Next, we will add an "AuthRedirect" page for handling the authentication result after the user have been authenticated by Authgear.
Create the
AuthRedirect.tsx
component file in the src/
folder. Call the Authgear
finishAuthentication()
function in the Auth Redirect component to send a token back to Authgear server in exchange for access token and refresh token. Don't worry about the technical jargons, finishAuthentication()
will do all the hard work for you and and save the authentication data.When the authentication is finished, the
isLoggedIn
state from the UserContextProvider will automatic set to true
. Finally, navigate back to root (/
) which is our Home page.The final
AuthRedirect.tsx
will look like this// src/AuthRedirect.tsx
import React, { useEffect, useRef } from "react";
import { useNavigate } from "react-router-dom";
import authgear from "@authgear/web";
const AuthRedirect: React.FC = () => {
const usedToken = useRef(false);
const navigate = useNavigate();
useEffect(() => {
async function updateToken() {
try {
await authgear.finishAuthentication();
} finally {
navigate("/");
usedToken.current = true;
}
}
if (!usedToken.current) {
updateToken().catch((e) => console.error(e));
}
}, [navigate]);
return <></>;
};
export default AuthRedirect;
Since in React 18, useEffect will be fired twice in development mode, we need to implement a cleanup function to stop it from firing twice. We will use an
useRef
Hook to stop the user token from being sent twice to the Authgear Endpoint.Without a cleanup function, an
useEffect
Hook will be fired twice and hence finishAuthentication() will
send the token back to Authgear Endpoint for two times, which the second one will result in "Invalid Token" error since the token can only be used once.Next, we will add a "Home" page . Create a
Home.tsx
component file the src/
folder. Then import Home and AuthRedirect as routes. And Import UserContextProvider and wrap the routes with it.
Your final
App.tsx
should look like this:// src/App.tsx
import React from "react";
import { BrowserRouter as Router, Routes, Route } from 'react-router-dom';
import Home from './Home';
import AuthRedirect from './AuthRedirect';
import UserContextProvider from './context/UserProvider';
const App: React.FC = () => {
return (
<UserContextProvider>
<Router>
<Routes>
<Route path="/auth-redirect" element={<AuthRedirect />} />
<Route path="/" element={<Home />} />
</Routes>
</Router>
</UserContextProvider>
);
}
export default App;
The file structure should now look like
src
├── App.tsx
├── AuthRedirect.tsx
├── Home.tsx
├── context
│ └── UserProvider.tsx
├── index.html
└── index.tsx
First we will import the Authgear dependency and the React Hook that we will use to
Home.tsx
. Then add the login button which will call startAuthentication(ConfigureOptions)
through startLogin
callback on click. This will redirect the user to the login page.// src/Home.tsx
import React, { useEffect, useState, useCallback, useContext } from 'react';
import authgear from '@authgear/web';
const Home: React.FC = () => {
const startLogin = useCallback(() => {
authgear
.startAuthentication({
redirectURI: 'http://localhost:4000/auth-redirect',
prompt: 'login'
})
.then(
() => {
// started authentication, user should be redirected to Authgear
},
err => {
// failed to start authentication
}
);
}, []);
return (
<div>
<h1>Home Page</h1>
<div>
<button onClick={startLogin}>Login</button>
</div>
</div>
);
}
export default Home;
You can now run
npm start
and you will be redirected to the Authgear Login page when you click the Login button.
User will be redirected to the Authgear login page by clicking the login button
The Authgear SDK helps you get the information of the logged in users easily.
In the last step, the user is successfully logged in so let's try to print the user ID (sub) of the user in the Home page.
In
Home.tsx
, we will add a simple Loading splash and a greeting message printing the Sub ID. We will add two conditional elements such that they are only shown when user is logged in. We can also change the login button to show only if the user is not logged in. Make use of
isLoggedIn
from the UserContext
to control the components on the page. Fetch the user info by fetchInfo()
and access its sub
property.// src/Home.tsx
import React, { useEffect, useState, useCallback, useContext } from "react";
import authgear from "@authgear/web";
import { UserContext } from "./context/UserProvider";
const Home: React.FC = () => {
const [greetingMessage, setGreetingMessage] = useState<string>("");
const [isLoading, setIsLoading] = useState<boolean>(false);
const { isLoggedIn } = useContext(UserContext);
useEffect(() => {
async function updateGreetingMessage() {
setIsLoading(true);
try {
if (isLoggedIn) {
const userInfo = await authgear.fetchUserInfo();
setGreetingMessage("The current User sub: " + userInfo.sub);
}
} finally {
setIsLoading(false);
}
}
updateGreetingMessage().catch((e) => {
console.error(e);
});
}, [isLoggedIn]);
const startLogin = useCallback(() => {
authgear
.startAuthentication({
redirectURI: "http://localhost:4000/auth-redirect",
prompt: "login",
})
.then(
() => {
// started authentication, user should be redirected to Authgear
},
(err) => {
// failed to start authentication
}
);
}, []);
return (
<div>
<h1>Home Page</h1>
{isLoading && "Loading"}
{greetingMessage ? <span>{greetingMessage}</span> : null}
{!isLoggedIn && (
<div>
<button type="button" onClick={startLogin}>
Login
</button>
</div>
)}
</div>
);
};
export default Home;
Run the app again, the User ID (sub) of the user should be printed on the Home page.
Finally, let's add an Logout button when user is logged in.
In
Home.tsx
, we will add a conditional elements in the elements:{isLoggedIn && (
<div>
<button onClick={logout}>Logout</button>
</div>
)}
And add the
logout
callback:const logout = useCallback(() => {
authgear
.logout({
redirectURI: "http://localhost:4000/",
})
.then(
() => {
setGreetingMessage('');
},
(err) => {
console.error(err);
}
);
}, []);
Run the app again, we can now logout by clicking the logout button.
Authgear provide a built-in UI for the users to set their attributes and change security settings.
Use the
openURL
function to open the setting page at <your_app_endpoint>/settings
In
Home.tsx
Add a conditional link to the elements.{isLoggedIn && (
<a target="_blank" rel="noreferrer" onClick={userSetting} href="#">
User Setting
</a>
)}
And add the
userSetting
callback:import authgear, { Page } from "@authgear/web";
const userSetting = useCallback((e: React.MouseEvent<HTMLAnchorElement>) => {
e.preventDefault();
e.stopPropagation();
authgear.open(Page.Settings);
}, []);
This the the resulting
Home.tsx
:// src/Home.tsx
import React, { useEffect, useState, useCallback, useContext } from "react";
import { UserContext } from "./context/UserProvider";
import authgear, { Page } from "@authgear/web";
const Home: React.FC = () => {
const [greetingMessage, setGreetingMessage] = useState<string>("");
const [isLoading, setIsLoading] = useState<boolean>(false);
const { isLoggedIn } = useContext(UserContext);
useEffect(() => {
async function updateGreetingMessage() {
setIsLoading(true);
try {
if (isLoggedIn) {
const userInfo = await authgear.fetchUserInfo();
setGreetingMessage("The current User sub: " + userInfo.sub);
}
} finally {
setIsLoading(false);
}
}
updateGreetingMessage().catch((e) => {
console.error(e);
});
}, [isLoggedIn]);
const startLogin = useCallback(() => {
authgear
.startAuthentication({
redirectURI: "http://localhost:4000/auth-redirect",
prompt: "login",
})
.then(
() => {
// started authorization, user should be redirected to Authgear
},
(err) => {
// failed to start authorization
console.error(err);
}
);
}, []);
const logout = useCallback(() => {
authgear
.logout({
redirectURI: "http://localhost:4000/",
})
.then(
() => {
setGreetingMessage("");
},
(err) => {
console.error(err);
}
);
}, []);
const userSetting = useCallback((e: React.MouseEvent<HTMLAnchorElement>) => {
e.preventDefault();
e.stopPropagation();
authgear.open(Page.Settings);
}, []);
return (
<div>
{/* eslint-disable-next-line react/forbid-elements */}
<h1>Home Page</h1>
{isLoading && "Loading"}
{greetingMessage ? <span>{greetingMessage}</span> : null}
{!isLoggedIn && (
<div>
<button type="button" onClick={startLogin}>
Login
</button>
</div>
)}
{isLoggedIn && (
<div>
<button type="button" onClick={logout}>
Logout
</button>
<br />
<a target="_blank" rel="noreferrer" onClick={userSetting} href="#">
User Setting
</a>
</div>
)}
</div>
);
};
export default Home;

Show the User ID, a link to User Settings and a logout button after login
To access restricted resources on your backend application server, the HTTP requests should include the access token in their Authorization headers. The Web SDK provides a
fetch
function which automatically handle this, or you can get the token with authgear.accessToken
.Authgear SDK provides the
fetch
function for you to call your application server. This fetch
function will include the Authorization header in your application request, and handle refresh access token automatically. The authgear.fetch
implements fetch.authgear
.fetch("YOUR_SERVER_URL")
.then(response => response.json())
.then(data => console.log(data));
You can get the access token through
authgear.accessToken
. Call refreshAccessTokenIfNeeded
every time before using the access token, the function will check and make the network call only if the access token has expired. Include the access token into the Authorization header of the application request.authgear
.refreshAccessTokenIfNeeded()
.then(() => {
// access token is ready to use
// accessToken can be string or undefined
// it will be empty if user is not logged in or session is invalid
const accessToken = authgear.accessToken;
// include Authorization header in your application request
const headers = {
Authorization: `Bearer ${accessToken}`
};
});
Last modified 2mo ago