$persistentStore#

$persistentStore gives a capture rule script a small key-value store that persists across runs and is shared between scripts. Use it to remember a token, a counter, or any small string between requests. It is available only inside capture rule scripts.

#Methods

$persistentStore.read(key?: string): string | null
$persistentStore.write(value: string, key?: string): boolean
$persistentStore.remove(key?: string): boolean

• read returns the stored string, or null if the key is absent.
• write stores a string and returns true.
• remove deletes the key and returns true.

If key is omitted, a default key is used.

#Notes

• Values are strings. To store structured data, serialize with JSON.stringify and parse with JSON.parse.
• The store is shared across all capture rule scripts and persists until removed.

#Example

// Remember the last seen request URL.
const previous = $persistentStore.read("last")
$persistentStore.write($request.url, "last")
console.log("previous:", previous)
$done({})

// Store and read a JSON object.
$persistentStore.write(JSON.stringify({ count: 3 }), "state")
const state = JSON.parse($persistentStore.read("state") || "{}")