CacheStorage

undici provides a spec-compliant implementation of the W3C Service Worker CacheStorage and Cache interfaces. A CacheStorage is a named collection of Cache objects, each of which stores Request/Response pairs.

The class itself is not exported; instead, undici exposes a single shared CacheStorage instance named caches. Import it from 'undici':

import { caches } from 'undici'

const cache = await caches.open('v1')

The shared CacheStorage instance exported by undici. All caches opened through caches live for the lifetime of the process.

import { caches } from 'undici'

await caches.open('v1')
console.log(await caches.keys()) // ['v1']

Represents the storage for Cache objects. Each CacheStorage keeps a mapping of cache names to their backing list of cached responses.

The constructor is not public: attempting to instantiate CacheStorage directly throws a TypeError. Use the exported caches instance instead.

caches.match(request, options?): Promise

Searches the caches for a response matching request. When options.cacheName is provided, only that cache is searched; otherwise every cache is searched in insertion order and the first match is returned.

import { caches } from 'undici'

const response = await caches.match('https://example.com/data', {
  cacheName: 'v1'
})

caches.has(cacheName): Promise

Checks whether a cache with the given name exists in the storage.

import { caches } from 'undici'

await caches.open('v1')
console.log(await caches.has('v1')) // true
console.log(await caches.has('v2')) // false

caches.open(cacheName): Promise

Opens the cache named cacheName, creating it if it does not already exist.

Each call returns a new Cache object, but caches opened with the same name share their underlying list of cached responses. As a result, a response stored through one instance is visible through another instance with the same name.

import { caches } from 'undici'
import assert from 'node:assert'

const cache1 = await caches.open('v1')
const cache2 = await caches.open('v1')

// open() returns distinct objects,
assert(cache1 !== cache2)
// but they share the same cached responses.
assert.deepStrictEqual(await cache1.match('/req'), await cache2.match('/req'))

caches.delete(cacheName): Promise

Removes the cache named cacheName from the storage. Any Cache objects already obtained for that name, along with the Request/Response pairs they returned, remain usable after deletion.

import { caches } from 'undici'

const cache = await caches.open('v1')
const response = await cache.match('/req')

await caches.delete('v1')

// The already-retrieved response is still usable.
await response.text()

caches.keys(): Promise

Returns the names of all caches currently held by the storage.

import { caches } from 'undici'

await caches.open('v1')
await caches.open('v2')
console.log(await caches.keys()) // ['v1', 'v2']