Cache Pages, API & Functions

Getting Started

Enable the cache storage in your NuxtHub project by adding the cache property to the hub object in your nuxt.config.ts file.

nuxt.config.ts

export default defineNuxtConfig({
  hub: {
    cache: true
  }
})

This option will configure Nitro's cache storage to use Cloudflare Workers KV as well as creating a new storage namespace for your project when you deploy it.

Once your Nuxt project is deployed, you can manage your cache entries in the Cache section of your project in the NuxtHub admin.

API Routes Caching

To cache Nuxt API and server routes, use the cachedEventHandler function. This function will cache the response of the server route into the cache storage.

server/api/cached-route.ts

import type { H3Event } from 'h3'

export default cachedEventHandler((event) => {
  return {
    success: true,
    date: new Date().toISOString()
  }
}, {
  maxAge: 60 * 60, // 1 hour
  getKey: (event: H3Event) => event.path
})

The above example will cache the response of the /api/cached-route route for 1 hour. The getKey function is used to generate the key for the cache entry.

Server Functions Caching

Using the cachedFunction function, You can cache the response of a server function based on the arguments passed to the function.

This is useful to cache the result of a function used in multiple API routes or within authenticated routes.

server/utils/cached-function.ts

import type { H3Event } from 'h3'

export const getRepoStarCached = defineCachedFunction(async (event: H3Event, repo: string) => {
  const data: any = await $fetch(`https://api.github.com/repos/${repo}`)

  return data.stargazers_count
}, {
  maxAge: 60 * 60, // 1 hour
  name: 'ghStars',
  getKey: (event: H3Event, repo: string) => repo
})

The above example will cache the result of the getRepoStarCached function for 1 hour.

It is important to note that the event argument should always be the first argument of the cached function. Nitro leverages event.waitUntil to keep the instance alive while the cache is being updated while the response is sent to the client.
Read more about this in the Nitro docs.

Cache Keys and Invalidation

When using the defineCachedFunction or defineCachedEventHandler functions, the cache key is generated using the following pattern:

`${options.group}:${options.name}:${options.getKey(...args)}.json`

For example, the following function:

const getAccessToken = defineCachedFunction(() => {
  return String(Date.now())
}, {
  maxAge: 10,
  name: 'getAccessToken',
  getKey: () => 'default'
})

Will generate the following cache key:

nitro:functions:getAccessToken:default.json

You can invalidate the cached function entry with:

await useStorage('cache').removeItem('nitro:functions:getAccessToken:default.json')