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FusionAuth React SDK

Overview

This SDK allows you to add login, logout, and registration buttons to your React application. You can do this via pre-built buttons, hooks, or higher-order components.

Your users will be sent to FusionAuth’s themeable hosted login pages and then log in. After that, they are sent back to your React application.

Once authentication succeeds, the following secure, HTTP-only cookies will be set:

  • app.at - an OAuth Access Token

  • app.rt - a Refresh Token used to obtain a new app.at. This cookie will only be set if refresh tokens are enabled on your FusionAuth instance.

The access token can be presented to APIs to authorize the request and the refresh token can be used to get a new access token.

Note that this SDK requires you to have a server that performs the OAuth token exchange. See Server Code Requirements for more details.

You can use this library against any version of FusionAuth or any OIDC compliant identity server.

Getting Started

Installation

NPM:

npm install @fusionauth/react-sdk

Yarn:

yarn add @fusionauth/react-sdk

Configuring Provider

To configure the SDK, wrap your app with FusionAuthProvider:

import React from 'react';
import { createRoot } from 'react-dom/client';
import { FusionAuthProvider } from '@fusionauth/react-sdk';
import App from './App';

const container = document.getElementById('root');
const root = createRoot(container!);

    root.render(
        <FusionAuthProvider
            clientID=""     // Your FusionAuth client ID
            serverUrl=""    // The base URL of your server for the token exchange
            redirectUri=""  // The URI that the user is directed to after the login/register/logout action
        >
            <App />
        </FusionAuthProvider>
    );

Server Code Requirements

Authenticating with FusionAuth requires you to set up a server that will be used to perform the OAuth token exchange. This server must have the following endpoints:

GET /app/login

This endpoint must:

  1. Generate PKCE code. a. The code verifier should be saved in a secure HTTP-only cookie. b. The code challenge is passed along
  2. Encode and save redirect_url from react app to state.
  3. Redirect browser to /oauth2/authorize with a redirect_uri to /app/token-exchange

Example implementation

GET /app/callback

This endpoint must:

  1. Call /oauth2/token to complete the Authorization Code Grant request. The code comes from the request query parameter and code_verifier should be available in the secure HTTP-only cookie, while the rest of the parameters should be set/configured on the server side.

  2. Once the token exchange succeeds, read the app.at from the response body and set it as a secure, HTTP-only cookie with the same name.

  3. If you wish to support refresh tokens, repeat step 2 for the app.rt cookie.

  4. Save the expiration time in a readable app.at_exp cookie. And save the app.idt id token in a readable cookie.

  5. Redirect browser back to encoded url saved in state.

  6. Call /oauth2/userinfo to retrieve the user info object and respond back to the client with this object.

Example implementation

GET /app/register

This endpoint is similar to /login. It must:

  1. Generate PKCE code. a. The code verifier should be saved in a secure HTTP-only cookie. b. The code challenge is passed along
  2. Encode and save redirect_url from react app to state.
  3. Redirect browser to /oauth2/register with a redirect_uri to /app/callback

Example implementation

GET /app/me

This endpoint must:

  1. Use app.at from cookie and use as the Bearer token to call /oauth2/userinfo
  2. Return json data

Example implementation

GET /app/logout

This endpoint must:

  1. Clear the app.at and app.rt secure, HTTP-only cookies.
  2. Clear the app.at_exp and app.idt secure cookies.
  3. Redirect to /oauth2/logout

Example implementation

POST /app/token-refresh (optional)

This endpoint is necessary if you wish to use refresh tokens. This endpoint must:

  1. Call /oauth2/token to get a new app.at and app.rt.

  2. Update the app.at, app.at_exp, app.idt, and app.rt cookies from the response.

Example implementation

Usage

Pre-built buttons

There are three pre-styled buttons that are configured to perform login/logout/registration. They can be placed anywhere in your app as is.

import {
  FusionAuthLoginButton,
  FusionAuthLogoutButton,
  FusionAuthRegisterButton
} from '@fusionauth/react-sdk';

export const LoginPage = () => (
  <>
    <h1>Welcome, please log in or register</h1>
    <FusionAuthLoginButton />
    <FusionAuthRegisterButton />
  </>
);

export const AccountPage = () => (
  <>
    <h1>Hello, user!</h1>
    <FusionAuthLogoutButton />
  </>
);

Programmatic usage

Alternatively, you may interact with the SDK programmatically using the useFusionAuth hook or withFusionAuth HOC.

useFusionAuth

Use the useFusionAuth hook with your functional components to get access to the properties exposed by FusionAuthContext:

import React from 'react';
import { useFusionAuth } from '@fusionauth/react-sdk';

const App = () => {
  const { login, logout, register, isAuthenticated } = useFusionAuth();

  return isAuthenticated ? (
    <div>
      <span>Hello, user!</span>
      <button onClick={() => logout()}>Logout</button>
    </div>
  ) : (
    <div>
      <button onClick={() => login()}>Log in</button>
      <button onClick={() => register()}>Register</button>
    </div>
  );
};

See useFusionAuth for more details.

withFusionAuth

The withFusionAuth higher-order component can be used to wrap your components and give them access to a fusionAuth prop which contains all the properties exposed by the FusionAuthContext. This works with both functional and class components:

Functional Component

import React from 'react';
import { withFusionAuth, WithFusionAuthProps } from '@fusionauth/react-sdk';

const LogoutButton: React.FC<WithFusionAuthProps> = props => {
  const { logout } = props.fusionAuth;

  return <button onClick={() => logout()}>Logout</button>;
}

export default withFusionAuth(LogoutButton);

Class Component

import React, { Component } from 'react';
import { withFusionAuth, WithFusionAuthProps } from '@fusionauth/react-sdk';

class LogoutButton extends Component<WithFusionAuthProps> {
  render() {
    const { logout } = this.props.fusionAuth;
    return <button onClick={() => logout()}>Logout</button>;
  }
}

export default withFusionAuth(LogoutButton);

See withFusionAuth for more details.

State parameter

The login and register functions both accept an optional string parameter called state. The state that is passed in to the function call will be passed back to the onRedirectSuccess handler on your FusionAuthProvider. Though you may pass any value you would like for the state parameter, it is often used to indicate which page the user was on before redirecting to login or registration, so that the user can be returned to that location after a successful authentication.

Protecting Content

The RequireAuth component can be used to protect information from unauthorized users. It takes an optional prop withRole that can be used to ensure the user has a specific role. If an array of roles is passed, the user must have at least one of the roles to be authorized.

import { RequireAuth, useFusionAuth } from '@fusionauth/react-sdk';

const UserNameDisplay = () => {
  const { user } = useFusionAuth();

  return (
    <RequireAuth>
      <p>User: {user.name}</p> // Only displays if user is authenticated
    </RequireAuth>
  );
};

const AdminPanel = () => (
  <RequireAuth withRole="admin">
    <button>Delete User</button> // Only displays if user is authenticated and has 'admin' role
  </RequireAuth>
);

Known Issues

Token exchange endpoint being called repeatedly

If you see the token exchange endpoint being called multiple times, this is due to a dev time setting in React 18. When running using StrictMode in development mode, React 18 will mount, unmount, and remount all components in this mode, which results in the network call running twice.

This will not happen in a production build or if StrictMode is disabled.

If you remove the React.StrictMode tags in index.tsx of the example app, the call is only made once.

Example App

See the FusionAuth React SDK Example for functional example of a React client that utilizes the SDK as well as an Express server that performs the token exchange.

Documentation

Full library documentation