Middleware

LiteNode supports middleware both globally (applied to every request) and per-route (applied to specific routes). Middleware functions receive req and res and run before the final route handler.

Global Middleware — use()

Signature:

use(middleware: RouteHandler): LiteNode

Registers a middleware that runs on every incoming request.

// Request logger
app.use(async (req, res) => {
    console.log(`[${req.method}] ${req.url}`)
})

Multiple use() calls are executed in registration order:

app.use(logger)
app.use(authenticate)
app.use(attachRequestId)

Per-Route Middleware

Pass middleware functions as arguments between the route path and the handler:

const addTimestamp = async (req, res) => {
    req.timestamp = new Date()
}

app.get("/time", addTimestamp, (req, res) => {
    res.txt(`Request at: ${req.timestamp}`)
})

Multiple middleware functions can be chained on the same route:

app.get("/admin/dashboard", authenticate, requireAdmin, (req, res) => {
    res.render("admin/dashboard.html", { user: req.user })
})

next()

Middleware functions automatically advance to the next handler when they return. There is no explicit next() call required — just return from the function:

const authenticate = async (req, res) => {
    const token = req.headers["authorization"]
    if (!token) {
        // Ending the response here stops the chain
        return res.status(401).json({ error: "Unauthorized" })
    }
    // Returning without ending the response passes control forward
    req.user = await verifyToken(token)
}

app.get("/profile", authenticate, (req, res) => {
    res.json({ user: req.user })
})

Middleware with merge() and nest()

Middleware can be scoped to merged or nested routers. See Merge and Nest for full details.

app.merge(apiRouter, rateLimiter)
app.nest("/admin", adminRouter, authenticate)

See the Examples page for auth, logging, and rate-limiting patterns.