incrementalCacheHandlerPath

In Next.js, the default cache handler ↗ uses the filesystem cache. This requires no configuration, however, you can customize the cache handler by using the incrementalCacheHandlerPath field in next.config.js.

next.config.js

module.exports = {
  experimental: {
    incrementalCacheHandlerPath: require.resolve('./cache-handler.js'),
  },
}

Here’s an example of a custom cache handler:

cache-handler.js

const cache = new Map()
 
module.exports = class CacheHandler {
  constructor(options) {
    this.options = options
    this.cache = {}
  }
 
  async get(key) {
    return cache.get(key)
  }
 
  async set(key, data) {
    cache.set(key, {
      value: data,
      lastModified: Date.now(),
    })
  }
}

API Reference

The cache handler can implement the following methods: get, set, and revalidateTag.

get()

Returns the cached value or null if not found.

set()

Returns Promise<void>.

revalidateTag()

Returns Promise<void>. Learn more about revalidating data ↗ or the revalidateTag() function.