Frequently asked questions

No. A store is a module-level value; any component that imports it can use it. Use useRestateScope when state should belong to one component instance.

Calling the hook without a selector subscribes to the whole value. Pass a selector that returns only what the component shows.

A new object is never Object.is-equal to the previous one. Pass shallow as the second argument, or select the fields separately.

set received the same object, so restate saw no change. Return a new object or array from set.

Once, at the client entry: await restateManager.ready before rendering the app. Components then read saved values directly. Stores in a useRestateScope wait for their own scope.manager.ready.

Only when you call save(), or after changes when autoSave is on. Editing changes memory; status().dirty tells you there are unsaved changes.

Use autoSave for settings and drafts that should always persist. Use save() when the user decides, such as a Save button or a form submission. You can call save() even with autoSave on, for example on pagehide.

When storage is unavailable the store keeps working in memory, status().available is false and save() rejects with STORAGE_UNAVAILABLE. Startup still succeeds.

It rejects with BULK_OPERATION_FAILED when a record could not be read, migrated or validated. error.failures names each store and its error. Fix or clear the record, call that store’s initialize(), and access ready again.

Storage is slower than the work you queue. Avoid calling save() in a tight loop — a waiting save already takes the newest value — or use autoSave with a delay. Tune maxPendingOperations and operationTimeoutMs if needed.

set() and reset() on a destroyed store are ignored, like a React state update after unmount. Subscribing throws STORE_DESTROYED and storage commands reject.

The factory runs once, like a useState initializer. Render the component with a key for each document so a new document gets a new scope.

Pass the same server data as props on the server and the client, and create the store from it in useRestateScope. The initial value becomes the server snapshot.

Scoped saved stores start loading after the owning component commits on the client. Wait for scope.manager.ready in a loading boundary inside that component.

Install react-native-mmkv and its native dependencies, then rebuild the app. In Expo, use a development build. Memory stores work without MMKV.