--- title: Hono description: "Implement secure authentication in Hono applications with ZITADEL and Auth.js using the OAuth 2.0 PKCE flow." sidebar_label: Hono framework_url: https://hono.dev auth_library: "Auth.js" auth_library_url: https://authjs.dev example_repo: https://github.com/zitadel/example-auth-hono auth_flow: pkce status: stable --- ## Overview [Hono](https://hono.dev) is a small, simple, and ultra-fast web framework for the Edges that works on Cloudflare Workers, Fastly Compute, Deno, Bun, Vercel, Netlify, AWS Lambda, Lambda@Edge, and Node.js. This example demonstrates how to integrate **Zitadel** using the **[OAuth 2.0 PKCE flow](https://oauth.net/2/pkce/)** to authenticate users securely and maintain sessions across your Hono application. #### Auth library This example uses **[Auth.js](https://authjs.dev)** (formerly NextAuth.js), the standard authentication library for modern web frameworks. Auth.js implements the [OpenID Connect](https://openid.net/connect/) (OIDC) protocol with [PKCE](https://oauth.net/2/pkce/), performs secure token exchange, and provides session management helpers. The integration uses **[@hono/auth-js](https://www.npmjs.com/package/@hono/auth-js)**, the official Hono adapter for Auth.js, along with **[@auth/core](https://www.npmjs.com/package/@auth/core)** which handles the core OIDC flows and the **[Zitadel provider](https://authjs.dev/reference/core/providers/zitadel)**. --- ## What this example demonstrates This example showcases a complete web application authentication pattern with [Hono](https://hono.dev) and [Zitadel](https://zitadel.com/docs). Users start on a public landing page, initiate authentication with Zitadel using the secure [PKCE flow](https://oauth.net/2/pkce/), and are redirected to a protected profile page displaying their [user information](https://zitadel.com/docs/apis/openidoauth/claims) after successful authentication. The application demonstrates several key features including sign-in with [authorization code flow + PKCE](https://oauth.net/2/pkce/), OAuth callback handling with secure [session storage](https://authjs.dev/concepts/session-strategies) using [JWT strategy](https://authjs.dev/concepts/session-strategies#jwt-session), route protection through [authentication middleware](https://hono.dev/docs/guides/middleware) that guards sensitive pages, automatic [token refresh](https://authjs.dev/guides/refresh-token-rotation) to maintain long-lived sessions without requiring re-authentication, access to user profile information including [OIDC standard claims](https://zitadel.com/docs/apis/openidoauth/claims) and [Zitadel-specific claims](https://zitadel.com/docs/apis/openidoauth/claims#reserved-claims) such as organization roles and metadata, and secure sign-out with [federated logout](https://zitadel.com/docs/guides/integrate/login/oidc/logout) that terminates both the local session and the Zitadel session through the end-session endpoint. The implementation uses [Handlebars templates](https://handlebarsjs.com/) for server-side rendering, [@hono/node-server](https://www.npmjs.com/package/@hono/node-server) for running on Node.js, secure [HTTP-only cookies](https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies#security) for session management, and [CSRF protection](https://authjs.dev/concepts/session-strategies#csrf-protection) through Auth.js built-in tokens. The authentication flow follows OAuth 2.0 best practices with [Proof Key for Code Exchange](https://zitadel.com/docs/guides/integrate/login/oidc/oauth-recommended-flows) to prevent authorization code interception attacks. --- ## Getting started ### Prerequisites Before running this example, you need to create and configure a PKCE application in the [ZITADEL Management Console](https://zitadel.com/docs/guides/manage/console/console-overview). Follow the PKCE application setup guide to: 1. Create a new Web application in your [Zitadel project](https://zitadel.com/docs/guides/manage/console/projects-overview) 2. Configure it to use the PKCE authentication method 3. Set up your redirect URIs (e.g., `http://localhost:3000/auth/callback/zitadel` for development) 4. Configure post-logout redirect URIs (e.g., `http://localhost:3000/auth/logout/callback`) 5. Copy your **Client ID** for use in the next steps > **Note:** Make sure to enable **Dev Mode** in the [ZITADEL Management Console](https://zitadel.com/docs/guides/manage/console/console-overview) if you're using HTTP URLs during local development. For production, always use HTTPS URLs and disable Dev Mode. ### Run the example Once you have your Zitadel application configured: 1. Clone the [repository](https://github.com/zitadel/example-auth-hono). 2. Create a `.env` file (copy from `.env.example`) and configure it with the values from your [Zitadel application](https://zitadel.com/docs/guides/manage/console/applications-overview). **Use the exact environment variable names from the repository:** ``` NODE_ENV=development PORT=3000 SESSION_SECRET=your-very-secret-and-strong-session-key SESSION_DURATION=3600 ZITADEL_DOMAIN=https://your-instance.zitadel.cloud ZITADEL_CLIENT_ID=your_client_id_from_console ZITADEL_CLIENT_SECRET= ZITADEL_CALLBACK_URL=http://localhost:3000/auth/callback/zitadel ZITADEL_POST_LOGIN_URL=/profile ZITADEL_POST_LOGOUT_URL=http://localhost:3000/auth/logout/callback ``` Replace these values with: - Your actual **Zitadel instance URL** (the Issuer from your [instance settings](https://zitadel.com/docs/guides/manage/console/default-settings)) - The **Client ID** you copied when creating the application in the PKCE setup - The **redirect URI** you configured in the PKCE setup (must match exactly) - The **post-logout redirect URI** for handling logout callbacks - A strong random **session secret** (generate using: `node -e "console.log(require('crypto').randomBytes(32).toString('hex'))"`) > **Note:** While PKCE doesn't require a client secret for public clients, Auth.js requires a value for internal settings. You can leave `ZITADEL_CLIENT_SECRET` empty or provide a random string. 3. Install dependencies using [npm](https://www.npmjs.com) and start the development server: ```bash npm install npm run dev ``` The application will be running at `http://localhost:3000`. Visit the homepage to test the authentication flow. --- ## Learn more and resources * [PKCE concept](https://oauth.net/2/pkce/) * [Federated logout](https://zitadel.com/docs/guides/integrate/login/oidc/logout) * [OIDC integration guide](https://zitadel.com/docs/guides/integrate/login/oidc/login-users) * [OAuth recommended flows](https://zitadel.com/docs/guides/integrate/login/oidc/oauth-recommended-flows) * [Framework docs](https://hono.dev) * [Auth.js](https://authjs.dev) * [Auth.js Hono adapter](https://www.npmjs.com/package/@hono/auth-js) * [Example repository](https://github.com/zitadel/example-auth-hono)