Utils

Nitro helps you to stay organized allowing you to take advantage of the auto-imports feature.

Every export in the utils directory and its subdirectories will become available globally in your application.

Example: Create a utils/sum.ts file where a function useSum is exported:

export function useSum(a: number, b: number) { return a + b }

Use it in your routes/index.ts file without importing it:

export default defineEventHandler(() => {  const sum = useSum(1, 2) // auto-imported  return { sum }})

Experimental Composition API

Nitro (2.6+) enables a new server development experience in order to split application logic into smaller "composable" utilities that are fully decoupled from each other and can directly assess to a shared context (request event) without needing it to be passed along. This pattern is inspired from Vue Composition API and powered by unjs/unctx.

This feature is currently supported for Node.js and Bun runtimes and also coming soon to other presets that support AsyncLocalStorage interface.

In order to enable composition API, you have to enable asyncContext flag:

export default defineNitroConfig({  experimental: {    asyncContext: true  }});

export default defineNuxtConfig({  nitro: {    experimental: {      asyncContext: true    }  }})

After enabling this flag, you can use useEvent() (auto imported) in any utility or composable to access the request event without manually passing it along:

// routes/index.tsexport default defineEventHandler(async () => {  const user = await useAuth()})// utils/auth.tsexport function useAuth() {  return useSession(useEvent())}

// routes/index.tsexport default defineEventHandler(async (event) => {  const user = await useAuth(event)})// utils/auth.tsexport function useAuth(event) {  return useSession(event)}