Features

Features are cross-cutting capabilities of Express that span multiple files in lib/ and external packages. Where a system page tells you what's in a single file, a feature page tells you how a piece of user-visible behaviour comes together.

Pages

• Routing and middleware — app.use, app.METHOD, Router, Route, mounting
• Body parsing — express.json, express.urlencoded, express.text, express.raw (re-exports of body-parser)
• Static files — express.static (re-export of serve-static) and res.sendFile (send package)
• Templating — app.engine, app.render, res.render, View
• Content negotiation — req.accepts, req.is, res.format
• Cookies and sessions — res.cookie, res.clearCookie, ecosystem packages

How to choose

If you want to know how to do something user-facing, start here. If you want to know what's inside a specific file, start in Systems.