> For the complete documentation index, see [llms.txt](https://openai.gitbook.io/code-cheatsheets/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://openai.gitbook.io/code-cheatsheets/js/all/node/packages/middleware.md).

# Essential Middleware

[Common Express Middleware](https://expressjs.com/en/resources/middleware.html>)

* body-parser: parses request bodies for POST parameters.
  * ```javascript
    const bodyParser = require('body-parser');
    app.use(bodyParser.json());
    ```
    * builtin express.json() will work for most cases, bodyParser works when raw json text in postman with single quotes while express.json wont
* cookie-parser: Used to parse the cookie header and populate req.cookies (essentially provides a convenient method for accessing cookie information).
  * ```javascript
    const cookieParser = require("cookie-parser");
    app.use(cookieParser());
    ```
* cors: Enable cross origin stuff globally
  * ```javascript
    const cors = require("cors");
    app.use(cors());
    ```
* morgan: An HTTP request logger middleware for node.
  * ```javascript
    app.use(morgan('dev'))
    //=> GET / 200 17.199 ms - -
    ```
* serve-favicon: Node middleware for serving a favicon (this is the icon used to represent the site inside the browser tab, bookmarks, etc.).