Introduction

In the previous post, we explored what Nitro plugins are and why they’re one of Nitro’s most powerful features. In this tutorial-focused follow-up, we’ll build real Nitro plugins step by step — the kind you’d actually use in production.

By the end, you’ll know how to create plugins for:

• Request logging
• API key authentication
• Response caching
• Feature flags and runtime configuration

All examples use TypeScript and work in Nuxt + Nitro or standalone Nitro apps.

Project Setup

Assuming a Nitro or Nuxt project, your folder structure should include:

server/
  plugins/
    logger.ts
    auth.ts
    cache.ts
    feature-flags.ts
Nitro automatically loads plugins from server/plugins/.

Tutorial 1: Request Logger Plugin

Goal Log every incoming request with method, path, and timing.

Step 1: Create the Plugin // server/plugins/logger.ts export default defineNitroPlugin((nitroApp) => { nitroApp.hooks.hook("request", (event) => { const start = Date.now()

event.node.res.on("finish", () => {
  const duration = Date.now() - start
  console.log(
    `[${event.method}] ${event.path} - ${duration}ms`
  )
})

}) })

What This Does#

Hooks into every request

Measures request duration

Logs after the response finishes

When to Use Debugging slow endpoints

Monitoring API usage

Lightweight analytics

Tutorial 2: API Key Authentication Plugin#

Goal Protect your API by validating an API key before routes run.

Step 1: Define a Validator const VALID_KEYS = new Set("dev-key-123", "prod-key-456")

function isValidKey(key?: string | null) { return key && VALID_KEYS.has(key) } Step 2: Create the Plugin // server/plugins/auth.ts export default defineNitroPlugin((nitroApp) => { nitroApp.hooks.hook("request", (event) => { const apiKey = event.headers.get("x-api-key")

if (!isValidKey(apiKey)) {
  throw createError({
    statusCode: 401,
    statusMessage: "Invalid API Key"
  })
}

}) })

Why This Is Powerful#

No auth logic in individual routes

Centralized, reusable security

Easy to extend with JWT or OAuth later

Tutorial 3: Simple Response Caching Plugin#

Goal Cache GET responses for frequently accessed endpoints (menus, products, settings).

Step 1: Create an In-Memory Cache const cache = new Map<string, { value: any; expires: number }>() const TTL = 60_000 // 60 seconds Step 2: Build the Plugin // server/plugins/cache.ts export default defineNitroPlugin((nitroApp) => { nitroApp.hooks.hook("request", async (event) => { if (event.method !== "GET") return

const key = event.path
const cached = cache.get(key)

if (cached && cached.expires > Date.now()) {
  return cached.value
}

})

nitroApp.hooks.hook("afterResponse", (event, response) => { if (event.method !== "GET") return

cache.set(event.path, {
  value: response,
  expires: Date.now() + TTL
})

}) })

Real-World Use Case#

Food truck menu API

Business hours endpoint

Pricing data

Tutorial 4: Feature Flags Plugin#

Goal Enable or disable features at runtime without touching routes.

Step 1: Define Flags const flags = { seasonalMenu: true, enableDiscounts: false } Step 2: Attach Flags to Runtime // server/plugins/feature-flags.ts export default defineNitroPlugin((nitroApp) => { nitroApp.hooks.hook("request", (event) => { event.context.features = flags }) }) Step 3: Use in a Route export default defineEventHandler((event) => { if (event.context.features.seasonalMenu) { return { menu: "Winter Specials" } }

return { menu: "Standard Menu" } })

Why This Matters#

Toggle features instantly

Safe rollouts

Environment-based behavior

Combining Plugins for a Real App#

For a coffee shop or food truck API, you might use:

Plugin Purpose Logger Track traffic & performance Auth Secure admin endpoints Cache Speed up menu reads Feature Flags Enable promotions All without bloating your route handlers.

Best Practices#

Keep plugins focused on one responsibility

Avoid heavy computation in request hooks

Use plugins for cross-cutting concerns, not business logic

Prefer plugins over middleware duplication ::

Conclusion

Nitro plugins give you framework-level power without framework-level complexity. Instead of repeating logic in routes, plugins let you build reusable, centralized behaviors that scale with your app.

If you’re serious about building maintainable APIs — whether for Nuxt apps, serverless deployments, or edge runtimes — mastering Nitro plugins is a game changer. 🚀