feat: implement BackupTransferRunner for managing backup processes and enhance backup handling

src/durable/backup-transfer-runner.ts

@@ -0,0 +1,293 @@
+import type { Env } from '../types';
+import type { BackupDestinationRecord } from '../services/backup-config';
+import {
+  BACKUP_SCHEDULER_WINDOW_MINUTES,
+  hasBackupSlotBetween,
+  isBackupDueNow,
+  loadBackupSettings,
+} from '../services/backup-config';
+import { createRemoteBackupTransferSession } from '../services/backup-uploader';
+import { getBlobObject } from '../services/blob-store';
+import { StorageService } from '../services/storage';
+import { notifyUserBackupProgress } from './notifications-hub';
+import { executeConfiguredBackup } from '../handlers/backup';
+
+const BACKUP_JOB_STATE_KEY = 'backup.job.state.v1';
+const BACKUP_JOB_LEASE_MS = 10 * 60 * 1000;
+const BACKUP_JOB_HEARTBEAT_MS = 30 * 1000;
+
+interface BackupJobState {
+  token: string;
+  reason: string;
+  acquiredAt: string;
+  touchedAt: string;
+  expiresAtMs: number;
+}
+
+interface RemoteAttachmentChunkRequest {
+  destination: BackupDestinationRecord;
+  attachments: Array<{
+    blobName: string;
+  }>;
+}
+
+interface ConfiguredBackupRunRequest {
+  actorUserId?: string | null;
+  auditMetadata?: Record<string, unknown> | null;
+  destinationId?: string | null;
+  targetDeviceIdentifier?: string | null;
+  trigger?: 'manual' | 'scheduled';
+}
+
+function badRequest(message: string, status: number = 400): Response {
+  return new Response(JSON.stringify({ error: message }), {
+    status,
+    headers: {
+      'Content-Type': 'application/json; charset=utf-8',
+      'Cache-Control': 'no-store',
+    },
+  });
+}
+
+export class BackupTransferRunner {
+  private lastHeartbeatAt = 0;
+
+  constructor(
+    private readonly state: DurableObjectState,
+    private readonly env: Env
+  ) {
+  }
+
+  private async acquireJob(reason: string): Promise<string | null> {
+    const nowMs = Date.now();
+    const current = await this.state.storage.get<BackupJobState>(BACKUP_JOB_STATE_KEY);
+    if (current?.expiresAtMs && current.expiresAtMs > nowMs) {
+      return null;
+    }
+
+    const token = crypto.randomUUID();
+    const nowIso = new Date(nowMs).toISOString();
+    await this.state.storage.put<BackupJobState>(BACKUP_JOB_STATE_KEY, {
+      token,
+      reason,
+      acquiredAt: nowIso,
+      touchedAt: nowIso,
+      expiresAtMs: nowMs + BACKUP_JOB_LEASE_MS,
+    });
+    this.lastHeartbeatAt = 0;
+    return token;
+  }
+
+  private async touchJob(token: string): Promise<void> {
+    const nowMs = Date.now();
+    if (nowMs - this.lastHeartbeatAt < BACKUP_JOB_HEARTBEAT_MS) return;
+    this.lastHeartbeatAt = nowMs;
+
+    const current = await this.state.storage.get<BackupJobState>(BACKUP_JOB_STATE_KEY);
+    if (current?.token !== token) return;
+
+    await this.state.storage.put<BackupJobState>(BACKUP_JOB_STATE_KEY, {
+      ...current,
+      touchedAt: new Date(nowMs).toISOString(),
+      expiresAtMs: nowMs + BACKUP_JOB_LEASE_MS,
+    });
+  }
+
+  private async releaseJob(token: string): Promise<void> {
+    const current = await this.state.storage.get<BackupJobState>(BACKUP_JOB_STATE_KEY);
+    if (current?.token === token) {
+      await this.state.storage.delete(BACKUP_JOB_STATE_KEY);
+    }
+  }
+
+  private async runConfiguredBackup(request: Request): Promise<Response> {
+    let body: ConfiguredBackupRunRequest;
+    try {
+      body = await request.json<ConfiguredBackupRunRequest>();
+    } catch {
+      return badRequest('Backup run payload is invalid');
+    }
+
+    const trigger = body.trigger === 'scheduled' ? 'scheduled' : 'manual';
+    const actorUserId = String(body.actorUserId || '').trim() || null;
+    if (trigger === 'manual' && !actorUserId) {
+      return badRequest('Manual backup run requires an actor');
+    }
+
+    const token = await this.acquireJob(`${trigger}:${actorUserId || 'system'}`);
+    if (!token) {
+      return badRequest('Another backup run is already in progress', 409);
+    }
+
+    try {
+      await this.touchJob(token);
+      const storage = new StorageService(this.env.DB);
+      const progress = actorUserId
+        ? async (event: {
+          operation: 'backup-remote-run';
+          step: string;
+          fileName: string;
+          stageTitle: string;
+          stageDetail: string;
+          done?: boolean;
+          ok?: boolean;
+          error?: string | null;
+        }) => {
+          await notifyUserBackupProgress(
+            this.env,
+            actorUserId,
+            event,
+            String(body.targetDeviceIdentifier || '').trim() || null
+          );
+        }
+        : null;
+
+      const result = await executeConfiguredBackup(
+        this.env,
+        storage,
+        actorUserId,
+        trigger,
+        body.destinationId || null,
+        () => this.touchJob(token),
+        progress,
+        body.auditMetadata || null
+      );
+      const settings = await loadBackupSettings(storage, this.env, 'UTC');
+
+      return new Response(JSON.stringify({
+        object: 'backup-runner-result',
+        result,
+        settings,
+      }), {
+        status: 200,
+        headers: {
+          'Content-Type': 'application/json; charset=utf-8',
+          'Cache-Control': 'no-store',
+        },
+      });
+    } catch (error) {
+      return badRequest(error instanceof Error ? error.message : 'Backup run failed', 500);
+    } finally {
+      await this.releaseJob(token);
+    }
+  }
+
+  private async runScheduledBackups(): Promise<Response> {
+    const token = await this.acquireJob('scheduled');
+    if (!token) {
+      return badRequest('Another backup run is already in progress', 409);
+    }
+
+    let completed = 0;
+    try {
+      await this.touchJob(token);
+      const storage = new StorageService(this.env.DB);
+      let scanStartMs = Date.now();
+
+      while (true) {
+        await this.touchJob(token);
+        const settings = await loadBackupSettings(storage, this.env, 'UTC');
+        const now = new Date();
+        const dueDestinations = settings.destinations.filter((destination) =>
+          isBackupDueNow(destination, now, BACKUP_SCHEDULER_WINDOW_MINUTES)
+          || hasBackupSlotBetween(destination, new Date(scanStartMs), now)
+        );
+
+        if (!dueDestinations.length) {
+          break;
+        }
+
+        scanStartMs = now.getTime();
+        for (const destination of dueDestinations) {
+          await this.touchJob(token);
+          await executeConfiguredBackup(
+            this.env,
+            storage,
+            null,
+            'scheduled',
+            destination.id,
+            () => this.touchJob(token)
+          );
+          completed += 1;
+        }
+      }
+
+      return new Response(JSON.stringify({
+        ok: true,
+        completed,
+      }), {
+        status: 200,
+        headers: {
+          'Content-Type': 'application/json; charset=utf-8',
+          'Cache-Control': 'no-store',
+        },
+      });
+    } catch (error) {
+      return badRequest(error instanceof Error ? error.message : 'Scheduled backup failed', 500);
+    } finally {
+      await this.releaseJob(token);
+    }
+  }
+
+  async fetch(request: Request): Promise<Response> {
+    const url = new URL(request.url);
+    if (request.method !== 'POST') {
+      return badRequest('Not found', 404);
+    }
+
+    if (url.pathname === '/internal/run-configured-backup') {
+      return this.runConfiguredBackup(request);
+    }
+
+    if (url.pathname === '/internal/run-scheduled-backups') {
+      return this.runScheduledBackups();
+    }
+
+    if (url.pathname !== '/internal/upload-attachment-chunk') {
+      return badRequest('Not found', 404);
+    }
+
+    let body: RemoteAttachmentChunkRequest;
+    try {
+      body = await request.json<RemoteAttachmentChunkRequest>();
+    } catch {
+      return badRequest('Attachment chunk payload is invalid');
+    }
+
+    if (!body?.destination || !Array.isArray(body.attachments)) {
+      return badRequest('Attachment chunk payload is invalid');
+    }
+
+    const remoteSession = createRemoteBackupTransferSession(body.destination);
+    let uploaded = 0;
+
+    for (const attachment of body.attachments) {
+      const blobName = String(attachment?.blobName || '').trim();
+      if (!blobName) {
+        return badRequest('Attachment chunk payload is invalid');
+      }
+
+      const object = await getBlobObject(this.env, blobName);
+      if (!object) {
+        return badRequest(`Attachment blob missing for ${blobName}`, 409);
+      }
+
+      const bytes = new Uint8Array(await new Response(object.body).arrayBuffer());
+      await remoteSession.putFile(`attachments/${blobName}`, bytes, {
+        contentType: object.contentType,
+      });
+      uploaded += 1;
+    }
+
+    return new Response(JSON.stringify({
+      ok: true,
+      uploaded,
+    }), {
+      status: 200,
+      headers: {
+        'Content-Type': 'application/json; charset=utf-8',
+        'Cache-Control': 'no-store',
+      },
+    });
+  }
+}

src/handlers/backup.ts

@@ -1,6 +1,5 @@
 import type { Env, User } from '../types';
 import { errorResponse, jsonResponse } from '../utils/response';
-import { generateUUID } from '../utils/uuid';
 import {
   type BackupArchiveBundle,
   buildBackupArchive,
@@ -10,12 +9,11 @@ import {
 import {
   type BackupDestinationRecord,
   type BackupSettingsInput,
-  BACKUP_SCHEDULER_WINDOW_MINUTES,
+  type BackupSettings,
+  type WebDavBackupDestination,
   getBackupLocalDateKey,
   getDefaultBackupSettings,
   getBackupSettingsRepairState,
-  hasBackupSlotBetween,
-  isBackupDueNow,
   loadBackupSettings,
   normalizeBackupSettingsInput,
   normalizeImportedBackupSettings,
@@ -86,102 +84,6 @@ function getBackupDestinationSummary(destination: BackupDestinationRecord | null
   };
 }
 
-const BACKUP_RUNNER_LOCK_KEY = 'backup.runner.lock.v1';
-const BACKUP_RUNNER_LEASE_MS = 10 * 60 * 1000;
-const BACKUP_RUNNER_HEARTBEAT_MS = 30 * 1000;
-
-// CONTRACT:
-// The runner lock is a config-row lease, not a queue. It only prevents two
-// backup/restore jobs from overlapping. Manual runs return conflict when the
-// lease is held; scheduled runs skip quietly. Never export this row in backups.
-interface BackupRunnerLease {
-  token: string;
-  touch: () => Promise<void>;
-  release: () => Promise<void>;
-}
-
-async function acquireBackupRunnerLease(env: Env, reason: string): Promise<BackupRunnerLease | null> {
-  const token = generateUUID();
-  const nowMs = Date.now();
-  const expiresAtMs = nowMs + BACKUP_RUNNER_LEASE_MS;
-  const value = JSON.stringify({
-    token,
-    reason,
-    acquiredAt: new Date(nowMs).toISOString(),
-    touchedAt: new Date(nowMs).toISOString(),
-    expiresAtMs,
-  });
-  const result = await env.DB
-    .prepare(
-      `INSERT INTO config(key, value) VALUES(?, ?)
-       ON CONFLICT(key) DO UPDATE SET value = excluded.value
-       WHERE COALESCE(CAST(json_extract(config.value, '$.expiresAtMs') AS INTEGER), 0) <= ?`
-    )
-    .bind(BACKUP_RUNNER_LOCK_KEY, value, nowMs)
-    .run();
-
-  if ((result.meta?.changes || 0) < 1) {
-    return null;
-  }
-
-  return {
-    token,
-    touch: async () => {
-      const nextNowMs = Date.now();
-      const nextValue = JSON.stringify({
-        token,
-        reason,
-        acquiredAt: new Date(nowMs).toISOString(),
-        touchedAt: new Date(nextNowMs).toISOString(),
-        expiresAtMs: nextNowMs + BACKUP_RUNNER_LEASE_MS,
-      });
-      await env.DB
-        .prepare(
-          `UPDATE config
-           SET value = ?
-           WHERE key = ?
-             AND json_extract(value, '$.token') = ?`
-        )
-        .bind(nextValue, BACKUP_RUNNER_LOCK_KEY, token)
-        .run();
-    },
-    release: async () => {
-      await env.DB
-        .prepare(
-          `DELETE FROM config
-           WHERE key = ?
-             AND json_extract(value, '$.token') = ?`
-        )
-        .bind(BACKUP_RUNNER_LOCK_KEY, token)
-        .run();
-    },
-  };
-}
-
-async function withBackupRunnerLease<T>(
-  env: Env,
-  reason: string,
-  task: (keepAlive: () => Promise<void>) => Promise<T>
-): Promise<T | null> {
-  const lease = await acquireBackupRunnerLease(env, reason);
-  if (!lease) return null;
-
-  let lastHeartbeatAt = 0;
-  const keepAlive = async () => {
-    const nowMs = Date.now();
-    if (nowMs - lastHeartbeatAt < BACKUP_RUNNER_HEARTBEAT_MS) return;
-    lastHeartbeatAt = nowMs;
-    await lease.touch();
-  };
-
-  try {
-    await keepAlive();
-    return await task(keepAlive);
-  } finally {
-    await lease.release();
-  }
-}
-
 function ensureBackupBlobName(value: string): string {
   const normalized = String(value || '').trim().replace(/\\/g, '/').replace(/^\/+|\/+$/g, '');
   if (!normalized) {
@@ -201,6 +103,36 @@ interface RemoteAttachmentIndexPayload {
   blobs: Record<string, { sizeBytes: number; updatedAt: string }>;
 }
 
+const REMOTE_ATTACHMENT_SYNC_EXTERNAL_SUBREQUEST_LIMIT = 50;
+const REMOTE_ATTACHMENT_SYNC_SUBREQUEST_RESERVE = 6;
+const REMOTE_ATTACHMENT_SYNC_MAX_WEB_DAV_BATCH_SIZE = 18;
+const REMOTE_ATTACHMENT_SYNC_MAX_S3_BATCH_SIZE = 40;
+
+function countRemotePathSegments(value: string): number {
+  return String(value || '').replace(/\\/g, '/').split('/').filter(Boolean).length;
+}
+
+function getRemoteAttachmentSyncBatchSize(destination: BackupDestinationRecord): number {
+  if (destination.type === 's3') {
+    return REMOTE_ATTACHMENT_SYNC_MAX_S3_BATCH_SIZE;
+  }
+
+  const remotePath = String((destination.destination as WebDavBackupDestination).remotePath || '');
+  const fixedWebDavDirectoryCalls = countRemotePathSegments(remotePath) + 1; // remotePath plus the shared "attachments" dir.
+  const available = REMOTE_ATTACHMENT_SYNC_EXTERNAL_SUBREQUEST_LIMIT
+    - REMOTE_ATTACHMENT_SYNC_SUBREQUEST_RESERVE
+    - fixedWebDavDirectoryCalls;
+
+  if (available < 2) {
+    throw new Error('WebDAV remote backup path is too deep for safe attachment batching');
+  }
+
+  return Math.max(1, Math.min(
+    REMOTE_ATTACHMENT_SYNC_MAX_WEB_DAV_BATCH_SIZE,
+    Math.floor(available / 2)
+  ));
+}
+
 async function loadRemoteAttachmentIndex(session: RemoteBackupTransferSession): Promise<Map<string, number>> {
   try {
     const file = await session.download(REMOTE_ATTACHMENT_INDEX_PATH);
@@ -256,7 +188,39 @@ async function saveRemoteAttachmentIndex(
   });
 }
 
-async function executeConfiguredBackup(
+async function uploadRemoteAttachmentChunk(
+  env: Env,
+  destination: BackupDestinationRecord,
+  attachments: Array<{ blobName: string }>
+): Promise<void> {
+  if (!attachments.length) return;
+  const id = env.BACKUP_TRANSFER_RUNNER.idFromName('remote-attachment-sync');
+  const stub = env.BACKUP_TRANSFER_RUNNER.get(id);
+  const response = await stub.fetch('https://backup-transfer/internal/upload-attachment-chunk', {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json; charset=utf-8',
+    },
+    body: JSON.stringify({
+      destination,
+      attachments,
+    }),
+  });
+  if (!response.ok) {
+    let message = `Attachment sync failed: ${response.status}`;
+    try {
+      const payload = await response.json<{ error?: string }>();
+      if (payload?.error) {
+        message = payload.error;
+      }
+    } catch {
+      // Ignore JSON parse failures and preserve the status-based error.
+    }
+    throw new Error(message);
+  }
+}
+
+export async function executeConfiguredBackup(
   env: Env,
   storage: StorageService,
   actorUserId: string | null,
@@ -331,25 +295,20 @@ async function executeConfiguredBackup(
     if (destination.includeAttachments) {
       await touchLease();
       const remoteAttachmentIndex = await loadRemoteAttachmentIndex(remoteSession);
-      let attachmentIndexChanged = false;
-      for (const attachment of archive.manifest.attachmentBlobs || []) {
+      const pendingAttachments = (archive.manifest.attachmentBlobs || [])
+        .filter((attachment) => remoteAttachmentIndex.get(attachment.blobName) !== attachment.sizeBytes);
+      const attachmentSyncBatchSize = getRemoteAttachmentSyncBatchSize(destination);
+      for (let i = 0; i < pendingAttachments.length; i += attachmentSyncBatchSize) {
         await touchLease();
-        if (remoteAttachmentIndex.get(attachment.blobName) === attachment.sizeBytes) {
-          continue;
-        }
-        const remotePath = `attachments/${attachment.blobName}`;
-        const object = await getBlobObject(env, attachment.blobName);
-        if (!object) {
-          throw new Error(`Attachment blob missing for ${attachment.blobName}`);
-        }
-        const bytes = new Uint8Array(await new Response(object.body).arrayBuffer());
-        await remoteSession.putFile(remotePath, bytes, {
-          contentType: object.contentType,
-        });
-        remoteAttachmentIndex.set(attachment.blobName, attachment.sizeBytes);
-        attachmentIndexChanged = true;
+        const chunk = pendingAttachments
+          .slice(i, i + attachmentSyncBatchSize)
+          .map((attachment) => ({ blobName: attachment.blobName }));
+        await uploadRemoteAttachmentChunk(env, destination, chunk);
       }
-      if (attachmentIndexChanged) {
+      if (pendingAttachments.length) {
+        for (const attachment of pendingAttachments) {
+          remoteAttachmentIndex.set(attachment.blobName, attachment.sizeBytes);
+        }
         await touchLease();
         await saveRemoteAttachmentIndex(remoteSession, remoteAttachmentIndex);
       }
@@ -474,6 +433,76 @@ async function executeConfiguredBackup(
   }
 }
 
+interface DurableBackupRunResponse {
+  result: {
+    fileName: string;
+    fileSize: number;
+    remotePath: string;
+    provider: string;
+  };
+  settings: BackupSettings;
+}
+
+async function runConfiguredBackupInDurableObject(
+  env: Env,
+  payload: {
+    actorUserId: string | null;
+    auditMetadata?: Record<string, unknown> | null;
+    destinationId?: string | null;
+    targetDeviceIdentifier?: string | null;
+    trigger: 'manual' | 'scheduled';
+  }
+): Promise<DurableBackupRunResponse | null> {
+  const id = env.BACKUP_TRANSFER_RUNNER.idFromName('configured-backup-runner');
+  const stub = env.BACKUP_TRANSFER_RUNNER.get(id);
+  const response = await stub.fetch('https://backup-transfer/internal/run-configured-backup', {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json; charset=utf-8',
+    },
+    body: JSON.stringify(payload),
+  });
+  if (response.status === 409) {
+    return null;
+  }
+  if (!response.ok) {
+    let message = `Backup run failed: ${response.status}`;
+    try {
+      const body = await response.json<{ error?: string }>();
+      if (body?.error) message = body.error;
+    } catch {
+      // Preserve the status-based message when the DO returns a non-JSON error.
+    }
+    throw new Error(message);
+  }
+  const body = await response.json<DurableBackupRunResponse>();
+  if (!body?.result || !body?.settings) {
+    throw new Error('Backup run response is invalid');
+  }
+  return body;
+}
+
+async function runScheduledBackupsInDurableObject(env: Env): Promise<void> {
+  const id = env.BACKUP_TRANSFER_RUNNER.idFromName('configured-backup-runner');
+  const stub = env.BACKUP_TRANSFER_RUNNER.get(id);
+  const response = await stub.fetch('https://backup-transfer/internal/run-scheduled-backups', {
+    method: 'POST',
+  });
+  if (response.status === 409) {
+    return;
+  }
+  if (!response.ok) {
+    let message = `Scheduled backup failed: ${response.status}`;
+    try {
+      const body = await response.json<{ error?: string }>();
+      if (body?.error) message = body.error;
+    } catch {
+      // Preserve the status-based message when the DO returns a non-JSON error.
+    }
+    throw new Error(message);
+  }
+}
+
 function toImportStatusCode(message: string): number {
   const lower = message.toLowerCase();
   if (lower.includes('invalid backup') || lower.includes('invalid json')) return 400;
@@ -526,30 +555,7 @@ async function runImportAndAudit(
 }
 
 export async function runScheduledBackupIfDue(env: Env): Promise<void> {
-  await withBackupRunnerLease(env, 'scheduled', async (keepAlive) => {
-    const storage = new StorageService(env.DB);
-    let scanStartMs = Date.now();
-
-    while (true) {
-      await keepAlive();
-      const settings = await loadBackupSettings(storage, env, 'UTC');
-      const now = new Date();
-      const dueDestinations = settings.destinations.filter((destination) =>
-        isBackupDueNow(destination, now, BACKUP_SCHEDULER_WINDOW_MINUTES)
-        || hasBackupSlotBetween(destination, new Date(scanStartMs), now)
-      );
-
-      if (!dueDestinations.length) {
-        return;
-      }
-
-      scanStartMs = now.getTime();
-      for (const destination of dueDestinations) {
-        await keepAlive();
-        await executeConfiguredBackup(env, storage, null, 'scheduled', destination.id, keepAlive);
-      }
-    }
-  });
+  await runScheduledBackupsInDurableObject(env);
 }
 
 export async function handleGetAdminBackupSettings(request: Request, env: Env, actorUser: User): Promise<Response> {
@@ -661,33 +667,12 @@ export async function handleRunAdminConfiguredBackup(request: Request, env: Env,
       return errorResponse('Backup run payload is invalid', 400);
     }
 
-    const targetDeviceIdentifier = String(request.headers.get('X-NodeWarden-Acting-Device-Id') || '').trim() || null;
-    const progress = async (event: {
-      operation: 'backup-remote-run';
-      step: string;
-      fileName: string;
-      stageTitle: string;
-      stageDetail: string;
-      done?: boolean;
-      ok?: boolean;
-      error?: string | null;
-    }) => {
-      await notifyUserBackupProgress(env, actorUser.id, event, targetDeviceIdentifier);
-    };
-    const outcome = await withBackupRunnerLease(env, `manual:${actorUser.id}`, async (keepAlive) => {
-      const storage = new StorageService(env.DB);
-      const result = await executeConfiguredBackup(
-        env,
-        storage,
-        actorUser.id,
-        'manual',
-        body?.destinationId || null,
-        keepAlive,
-        progress,
-        auditRequestMetadata(request)
-      );
-      const settings = await loadBackupSettings(storage, env, 'UTC');
-      return { result, settings };
+    const outcome = await runConfiguredBackupInDurableObject(env, {
+      actorUserId: actorUser.id,
+      auditMetadata: auditRequestMetadata(request),
+      destinationId: body?.destinationId || null,
+      targetDeviceIdentifier: String(request.headers.get('X-NodeWarden-Acting-Device-Id') || '').trim() || null,
+      trigger: 'manual',
     });
     if (!outcome) {
       return errorResponse('Another backup run is already in progress', 409);

src/index.ts

@@ -1,5 +1,6 @@
 import { Env } from './types';
 import { NotificationsHub } from './durable/notifications-hub';
+import { BackupTransferRunner } from './durable/backup-transfer-runner';
 import { handleRequest } from './router';
 import { StorageService } from './services/storage';
 import { applyCors, jsonResponse } from './utils/response';
@@ -127,3 +128,4 @@ export default {
 };
 
 export { NotificationsHub };
+export { BackupTransferRunner };

src/types/index.ts

@@ -2,6 +2,7 @@
 export interface Env {
   DB: D1Database;
   NOTIFICATIONS_HUB: DurableObjectNamespace;
+  BACKUP_TRANSFER_RUNNER: DurableObjectNamespace;
   ASSETS?: {
     fetch(input: RequestInfo | URL, init?: RequestInit): Promise<Response>;
   };