# Express > title: Express 3.x - API Reference ## Pages - [Express 3.x - API Reference](3x-api.md): **Express 3.x IS END-OF-LIFE AND NO LONGER MAINTAINED** - [Express 4.x - API Reference](4x-api.md): {% capture node-version %} - [Express 5.x - API Reference](5x-api.md): {% capture node-version %} - [Performance Best Practices Using Express in Production](advanced-best-practice-performance.md): This article discusses performance and reliability best practices for Express applications deployed to production. - [Security Best Practices for Express in Production](advanced-best-practice-security.md): The term _"production"_ refers to the stage in the software lifecycle when an application or API is generally availab... - [Developing template engines for Express](advanced-developing-template-engines.md): Use the`app.engine(ext, callback)`method to create your own template engine.`ext`refers to the file extension, an... - [Health Checks and Graceful Shutdown](advanced-healthcheck-graceful-shutdown.md): When you deploy a new version of your application, you must replace the previous version. The process manager you're ... - [Express security updates](advanced-security-updates.md): Node.js vulnerabilities directly affect Express. Therefore, [keep a watch on Node.js vulnerabilities](https://nodejs.... - [Express 5.x - API Reference](api.md): {% include api/en/5x/express.md %} - [Express Blog Posts](blog-posts.md): Want to write a post? See the submission [guidelines.](/en/blog/write-post.html) - [How to write a blog post](blog-write-post.md): If you have an idea for a blog post, follow these steps to propose it and potentially get it published! - [Express changelog](changelog.md): {% capture readme %}{% include changelog/menu.md %}{% endcapture %} - [Express behind proxies](guide-behind-proxies.md): When running an Express app behind a reverse proxy, some of the Express APIs may return different values than expecte... - [Express database integration](guide-database-integration.md): Adding the capability to connect databases to Express apps is just a matter of loading an appropriate Node.js driver ... - [Debugging Express](guide-debugging.md): To see all the internal logs used in Express, set the`DEBUG`environment variable to - [Express error handling](guide-error-handling.md): _Error Handling_ refers to how Express catches and processes errors that - [Migrating to Express 4](guide-migrating-4.md): Express 4 is a breaking change from Express 3. That means an existing Express 3 app will _not_ work if you update the... - [Migrating to Express 5](guide-migrating-5.md): Express 5 is not very different from Express 4; although it maintains the same basic API, there are still changes tha... - [Overriding the Express API](guide-overriding-express-api.md): The Express API consists of various methods and properties on the request and response objects. These are inherited b... - [Express routing](guide-routing.md): _Routing_ refers to how an application's endpoints (URIs) respond to client requests. - [Using Express middleware](guide-using-middleware.md): Express is a routing and middleware web framework that has minimal functionality of its own: An Express application i... - [Using template engines with Express](guide-using-template-engines.md): A _template engine_ enables you to use static template files in your application. At runtime, the template engine rep... - [Writing middleware for use in Express apps](guide-writing-middleware.md): _Middleware_ functions are functions that have access to the [request object](/{{ page.lang }}/5x/api.html#req) (`req... - [Express community](resources-community.md): The Express technical committee meets online every two weeks (as needed) to discuss development and maintenance of Ex... - [Contributing to Express](resources-contributing.md): Express and the other projects in the [expressjs organization on GitHub](https://github.com/expressjs) are projects o... - [Express glossary](resources-glossary.md): In general, one or more programs that are designed to carry out operations for a specific purpose. In the context of... - [Express body-parser middleware](resources-middleware-body-parser.md): layout: middleware - [Express compression middleware](resources-middleware-compression.md): layout: middleware - [Express connect-rid middleware](resources-middleware-connect-rid.md): layout: middleware - [Express cookie-parser middleware](resources-middleware-cookie-parser.md): layout: middleware - [Express cookie-session middleware](resources-middleware-cookie-session.md): layout: middleware - [Express cors middleware](resources-middleware-cors.md): layout: middleware - [Express errorhandler middleware](resources-middleware-errorhandler.md): layout: middleware - [Express method-override middleware](resources-middleware-method-override.md): layout: middleware - [Express morgan middleware](resources-middleware-morgan.md): layout: middleware - [Express multer middleware](resources-middleware-multer.md): layout: middleware - [Express response-time middleware](resources-middleware-response-time.md): layout: middleware - [Express serve-favicon middleware](resources-middleware-serve-favicon.md): layout: middleware - [Express serve-index middleware](resources-middleware-serve-index.md): layout: middleware - [Express serve-static middleware](resources-middleware-serve-static.md): layout: middleware - [Express session middleware](resources-middleware-session.md): layout: middleware - [Express timeout middleware](resources-middleware-timeout.md): layout: middleware - [Express vhost middleware](resources-middleware-vhost.md): layout: middleware - [Express middleware](resources-middleware.md): The Express middleware modules listed here are maintained by the - [Express utilities](resources-utils.md): The [pillarjs](https://github.com/pillarjs) GitHub organization contains a number of modules - [Express basic routing](starter-basic-routing.md): _Routing_ refers to determining how an application responds to a client request to a particular endpoint, which is a ... - [Express examples](starter-examples.md): {% capture examples %}{% include readmes/express-master/examples.md %}{% endcapture %} - [Express FAQ](starter-faq.md): There is no definitive answer to this question. The answer depends - [Express application generator](starter-generator.md): Use the application generator tool,`express-generator`, to quickly create an application skeleton. - [Express "Hello World" example](starter-hello-world.md): Embedded below is essentially the simplest Express app you can create. It is a single file app — _not_ what you... - [Installing Express](starter-installing.md): Assuming you've already installed [Node.js](https://nodejs.org/), create a directory to hold your application, and ma... - [Serving static files in Express](starter-static-files.md): To serve static files such as images, CSS files, and JavaScript files, use the`express.static`built-in middleware f... - [Version Support](support.md): Only the latest version of any given major release line is supported.