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Client SDK · Vanilla JSJavaScript realtime and files
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const snapshot = await qb.from('tasks');
const channel = qb.channel({
table: 'tasks',
cursor: snapshot.meta.consistencyToken,
onEvent: () => refreshTasks(),
onStatus: status => { connectionLabel.textContent = status; },
onResync: () => refreshTasks(),
}).subscribe();A subscription is an explicit resource. Dispose it when replacing the screen or leaving the application. Realtime delivery uses the current session and exposed-table policies.
const file = fileInput.files?.[0];
if (file) {
const uploaded = await qb.storage.upload(bucketId, file.name, file);
const blob = await qb.storage.download(uploaded.data.id);
const url = URL.createObjectURL(blob);
downloadLink.href = url;
downloadLink.download = file.name;
// Release after the UI no longer uses the URL:
URL.revokeObjectURL(url);
}Use an authenticated application user and a configured S3 backend. Private files are restricted to their owner.
channel.unsubscribe();
stopAuth();
qb.dispose();Call cleanup only when the instance is no longer used. dispose closes channels and removes session listeners. A disposed client rejects later requests.
Refetch and clear protected DOM state after signout. Keep every application's state scoped to its client and user; do not mix results from another project. The SDK reauthorizes its channels after identity changes, while your application remains responsible for clearing previously rendered private content.
The shared upload method accepts optional SHA-256 checksum and AbortSignal options. Server uploads stream through private disk staging before S3 persistence, with size/checksum verification, four-transfer concurrency and a 100 MiB maximum. This does not add resumable or native background uploads. See storage configuration and integrity examples.