DataStore namespace

League Client does not store user data on disk, similar to incognito mode in web browsers. This namespace helps you to store user data on disk.

The whole store is read from disk before any plugin runs, and kept in memory for the rest of the session. Reads (get, has) are therefore synchronous and safe to call from your plugin's init. Writes update memory immediately and commit to disk on a short debounce, so a burst of set calls (a settings slider, say) collapses into a single write.

DataStore.set()

functionsince v1.0.1

function set(key: string, value: unknown): boolean

Stores data associated with the specified key.

Parameters

• key (string) The key under which the data will be stored. Keys must be unique across all plugins to avoid conflicts.

• value (unknown) The value to store. Supported types include:

  • Primitive types: string, number, boolean, null
  • Collections: arrays, objects

All data is serialized into JSON format, so non-serializable types such as functions and runtime objects will be ignored.

Returns

true if the value was accepted, false if key was not a string.

The return value is not a write confirmation — it means "stored in memory, and it will reach disk shortly". Use flush() if you need to know the data is durable.

Example

let my_num = 10
let my_str = 'hello'
DataStore.set('my_num', my_num)
DataStore.set('my_str', my_str)

Remarks

To avoid data conflicts, use unique and descriptive key names, preferably prefixed with your plugin’s identifier. For example, use plugin-name/user-settings instead of generic names like settings or data.

For multiple data entries such as config or user settings, you should store them in an object.

let config = { a: 10, b: 'hello' }
DataStore.set('my-config', config)

DataStore.get()

functionsince v1.0.1

function get<T = unknown>(key: string, fallback?: T): T | undefined

Retrieves stored data by key. If the key does not exist, the function will return undefined or an optional fallback value.

This is a synchronous read against the in-memory copy, so it is safe to call from your plugin's init.

Parameters

• key (string) The key associated with the data.

• fallback (T) (optional) A default value to return if the key does not exist.

Returns

The stored data, or the fallback value if the key is missing.

Example

console.log(DataStore.get('my_str'))
// some string
console.log(DataStore.get('key-does-not-exist'))
// undefined

Since v1.0.5, you can set fallback value for non-existent keys.

console.log(DataStore.get('key-does-not-exist', 1000))
// 1000

DataStore.has()

functionsince v1.0.1

function has(key: string): boolean

Checks if a specific key exists in the storage.

Parameters

• key (string) The key to check.

Returns

A boolean value indicating whether the key exists.

Example

console.log(DataStore.has('my_num'))
console.log(DataStore.has('key-does-not-exist'))

DataStore.remove()

functionsince v1.0.1

function remove(key: string): boolean

Removes a key-value pair from storage.

Parameters

• key (string) The key of the data to remove.

Returns

• true if the key was found and removed.
• false if the key does not exist.

Like set, the removal applies to memory immediately and is committed to disk on the same debounce.

Example

DataStore.remove('some-key')
DataStore.has('some-key') // -> false

DataStore.flush()

functionsince v1.2.0

function flush(): Promise<void>

Writes any pending changes out immediately and resolves once they are durable on disk.

Most plugins never need this — the debounced commit already handles normal use. Reach for it when you are about to do something that could end the session before the debounce fires, such as calling restartClient().

Example

DataStore.set('my-config', config)
await DataStore.flush()
window.restartClient()