> ## Documentation Index
> Fetch the complete documentation index at: https://brushysuite.gfrancodev.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Configuration

> StorageOptions for createStorage.

Every option passed to `createStorage()` is optional. Defaults are tuned for in-memory caching with periodic expiry scans.

```typescript theme={null}
import { createStorage } from "@brushy/storage";

const cache = createStorage({
  id: "my-app",
  prefix: "@myapp:",
  stdTTL: 0,
  checkperiod: 600,
  useClones: false,
  deleteOnExpire: true,
  maxKeys: -1,
  persist: false,
  compress: false,
  onError: (error) => console.error(error),
});
```

## Options reference

<ParamField path="id" type="string" default="prefix or @brushy:">
  Unique instance id. Instances with the same `id` share a single in-process object and sync invalidation via the registry bus.
</ParamField>

<ParamField path="prefix" type="string" default="@brushy:">
  Prepended to keys in the persist layer. Does not affect in-memory key names.
</ParamField>

<ParamField path="stdTTL" type="number | string" default="0">
  Default TTL in seconds for `set()` when no per-key TTL is given. `0` = unlimited. Bare numeric strings use **milliseconds** for `stdTTL` (node-cache compatible). See [TTL](/storage/ttl).
</ParamField>

<ParamField path="checkperiod" type="number" default="600">
  Interval in **seconds** to scan for expired keys. Set to `0` to disable the background timer.
</ParamField>

<ParamField path="useClones" type="boolean" default="false">
  When `true`, values are deep-cloned on `get`/`set` via `structuredClone` (falls back to `JSON.parse`/`stringify`).
</ParamField>

<ParamField path="deleteOnExpire" type="boolean" default="true">
  When `true`, expired keys are removed and `expired` + `del` events fire. When `false`, the value remains with expiry cleared.
</ParamField>

<ParamField path="maxKeys" type="number" default="-1">
  Maximum in-memory keys. `-1` = unlimited. Throws `StorageError` (`MaxKeys`) when exceeded.
</ParamField>

<ParamField path="persist" type="false | 'local' | 'session' | SyncPersist" default="false">
  Write-through persistence. See [Persist adapters](/storage/persist).
</ParamField>

<ParamField path="bus" type="CacheBus">
  Custom invalidation bus merged with built-in registry and `BroadcastChannel` buses. See [Cache bus](/storage/cache-bus).
</ParamField>

<ParamField path="compress" type="boolean" default="false">
  LZ-string compress persist payloads larger than 1 KB.
</ParamField>

<ParamField path="onError" type="(error: StorageError) => void">
  Handler for persist quota, serialization, and max-keys errors.
</ParamField>

## Singleton instances

`createStorage({ id: "app" })` returns the same object on subsequent calls with the same `id`. Use distinct ids when you need isolated caches (e.g. feature-specific namespaces).

<Tip>
  For browser persist across tabs, use a stable `id` **and** `persist: "local"` or `"session"`.
</Tip>

## SetOptions (per-key)

Passed as the third argument to `set()` or via `useStorage` options:

<ParamField path="ttl" type="number | string">
  Per-key TTL. Bare numeric strings are interpreted as **seconds**.
</ParamField>

<ParamField path="compress" type="boolean">
  Override instance-level `compress` for this write.
</ParamField>