Add find_missing_ebooks scheduled job

Introduce a safety-net scheduled job that scans completed audiobooks and auto-triggers ebook fetches for missing companions. Changes include:

- New Prisma migration + schema field: requests.ebook_auto_retry_count (nullable) to track lifetime auto-retries.
- New processor: src/lib/processors/find-missing-ebooks.processor.ts implementing the scan (limit 50), gating by ebook_auto_grab_enabled and source flags, creating ebook child requests or retrying failed ones up to a cap of 5, using transactions for race-safety and rolling back the counter if enqueue fails.
- Job queue integration: add job type, payload, processor registration, and addFindMissingEbooksJob helper.
- Scheduler integration: register the scheduled job (daily midnight) and trigger path.
- Documentation updates: backend scheduler and ebook-sidecar docs describing behavior and limits.
- Tests: add comprehensive unit tests for the processor and update scheduler tests and job-queue test helper.

This implements automated recovery for missing ebook companions while keeping the retry counter processor-private and ensuring safe concurrency handling.

documentation/backend/services/scheduler.md

@@ -20,8 +20,9 @@ Manages recurring/scheduled jobs providing automated tasks (Plex scans, Audible
 3. **audible_refresh** - Default: daily midnight, fetches 200 popular + 200 new releases, stores with rankings, disabled by default
 4. **retry_missing_torrents** - Default: daily midnight, processes union of `awaiting_search` ∪ `awaiting_release` (limit 50), handles both audiobook and ebook requests. Bidirectional transitions: `awaiting_search` → `awaiting_release` when release date is future + `indexer.skip_unreleased` ON; `awaiting_release` → `awaiting_search` + run search when release date has passed or setting OFF. Sole owner of these transitions. Enabled by default.
 5. **retry_failed_imports** - Default: every 6 hours, re-attempts 'awaiting_import' status (limit 50), enabled by default
-6. **cleanup_seeded_torrents** - Default: every 30 mins, deletes torrents after seeding requirements met, respects `seeding_time_minutes` config (0 = never), enabled by default
+6. **find_missing_ebooks** - Default: daily midnight, scans `downloaded` ∪ `available` audiobook requests (limit 50) for missing ebook companions and triggers the existing ebook fetch flow (`addSearchEbookJob`). Gated by `ebook_auto_grab_enabled` AND at least one ebook source enabled (`ebook_annas_archive_enabled` or `ebook_indexer_search_enabled`; legacy `ebook_sidecar_enabled` accepted as Anna's fallback). Skips ebook children in-flight (`pending`, `awaiting_approval`, `searching`, `downloading`, `processing`, `awaiting_search`, `awaiting_release`) or `cancelled`. Retries `failed`/`warn` children up to **5 lifetime auto-retries** per audiobook, tracked in `Request.ebookAutoRetryCount` (nullable; processor-private — manual "Fetch Ebook" never reads/writes it). Per-candidate writes are wrapped in `prisma.$transaction` for race-safety with concurrent auto-grab; counter rolls back if `addSearchEbookJob` throws. Enabled by default. Returns `{ scanned, gapsFound, triggered, created, retried, skippedInFlight, skippedCancelled, skippedCapHit }`.
-7. **monitor_rss_feeds** - Default: every 15 mins, checks RSS feeds from enabled indexers, matches against `awaiting_search` requests (audiobook and ebook, limit 100). Query is unchanged — release-date gate is applied AFTER a match is found: if matched book is unreleased + `indexer.skip_unreleased` ON, the match is skipped and request status is NOT mutated (retry job owns transitions). Enabled by default.
+7. **cleanup_seeded_torrents** - Default: every 30 mins, deletes torrents after seeding requirements met, respects `seeding_time_minutes` config (0 = never), enabled by default
+8. **monitor_rss_feeds** - Default: every 15 mins, checks RSS feeds from enabled indexers, matches against `awaiting_search` requests (audiobook and ebook, limit 100). Query is unchanged — release-date gate is applied AFTER a match is found: if matched book is unreleased + `indexer.skip_unreleased` ON, the match is skipped and request status is NOT mutated (retry job owns transitions). Enabled by default.
 
 ## Architecture: Bull + Cron
 

documentation/integrations/ebook-sidecar.md

@@ -72,6 +72,10 @@ Ebooks are first-class citizens in RMAB, with their own request type, tracking,
 - *Auto-grab is automatically disabled if no ebook sources are enabled. Manual fetch via admin buttons still works.*
 - *Kindle fix toggle only visible when preferred format is EPUB.*
 
+### Safety-Net: Find Missing Ebooks Job
+
+A scheduled `find_missing_ebooks` job (daily midnight, enabled by default) backstops the auto-grab path for cases where it silently misses books (race conditions, transient indexer failures, requests created before sources were configured, books from Goodreads/Hardcover sync). Per run it scans up to 50 audiobook requests in `downloaded`/`available` status and triggers the existing ebook fetch flow for any audiobook missing a successful ebook companion. **Lifetime auto-retry cap: 5 per audiobook** — after 5 failed auto-attempts the job stops retrying that audiobook (admin Manual "Fetch Ebook" remains available). Counter is tracked in `Request.ebookAutoRetryCount` and is **processor-private**: manual Fetch Ebook routes never read, write, or reset it. Gated by `ebook_auto_grab_enabled` AND at least one source enabled; logs no-op runs honestly. See `documentation/backend/services/scheduler.md` for full details.
+
 ### Kindle EPUB Fix
 
 **Purpose:** Apply compatibility fixes to EPUB files before organizing, ensuring successful Kindle import.

prisma/migrations/20260516000000_add_ebook_auto_retry_count/migration.sql

@@ -0,0 +1,5 @@
+-- Add lifetime auto-retry counter for the find_missing_ebooks scheduled job.
+-- Nullable: NULL distinguishes "never touched by this job" from 0.
+-- Only the find-missing-ebooks processor reads/writes/increments this column.
+-- Manual Fetch Ebook routes do not touch it (counter is sacred per engineering brief).
+ALTER TABLE "requests" ADD COLUMN "ebook_auto_retry_count" INTEGER;

prisma/schema.prisma

@@ -234,6 +234,7 @@ model Request {
   downloadAttempts Int       @default(0) @map("download_attempts")
   importAttempts   Int       @default(0) @map("import_attempts")
   maxImportRetries Int       @default(5) @map("max_import_retries")
+  ebookAutoRetryCount Int?   @map("ebook_auto_retry_count")
   lastSearchAt     DateTime? @map("last_search_at")
   customSearchTerms String?  @map("custom_search_terms") @db.Text
   lastImportAt     DateTime? @map("last_import_at")

src/lib/processors/find-missing-ebooks.processor.ts

@@ -0,0 +1,298 @@
+/**
+ * Component: Find Missing Ebooks Processor
+ * Documentation: documentation/backend/services/scheduler.md
+ *
+ * Safety-net scheduled job for issue #191. Scans completed audiobook requests
+ * (downloaded | available) and triggers the existing ebook fetch flow for any
+ * audiobook whose ebook companion is missing, failed, or warned out.
+ *
+ * Gated by ebook_auto_grab_enabled AND at least one ebook source enabled.
+ * Per-run scan cap = 50. Per-audiobook lifetime auto-retry cap = 5
+ * (tracked in Request.ebookAutoRetryCount; counter is processor-private —
+ * manual Fetch Ebook never touches it).
+ */
+
+import { prisma } from '../db';
+import { RMABLogger } from '../utils/logger';
+import { getJobQueueService } from '../services/job-queue.service';
+import { getConfigService } from '../services/config.service';
+
+export interface FindMissingEbooksPayload {
+  jobId?: string;
+  scheduledJobId?: string;
+}
+
+interface CandidateRow {
+  parent_request_id: string;
+  user_id: string;
+  audiobook_id: string;
+  custom_search_terms: string | null;
+  audiobook_title: string;
+  audiobook_author: string;
+  audible_asin: string | null;
+  ebook_request_id: string | null;
+  ebook_status: string | null;
+  ebook_auto_retry_count: number | null;
+}
+
+// Statuses indicating an in-flight ebook request that must not be duplicated
+// or re-triggered. `awaiting_release` is included per engineering brief's
+// "include awaiting_release in the in-flight skip set" directive.
+const IN_FLIGHT_STATUSES = new Set([
+  'pending',
+  'awaiting_approval',
+  'searching',
+  'downloading',
+  'processing',
+  'awaiting_search',
+  'awaiting_release',
+]);
+
+const AUTO_RETRY_CAP = 5;
+const PER_RUN_LIMIT = 50;
+
+export async function processFindMissingEbooks(payload: FindMissingEbooksPayload): Promise<any> {
+  const { jobId } = payload;
+  const logger = RMABLogger.forJob(jobId, 'FindMissingEbooks');
+
+  logger.info('Starting find_missing_ebooks pass');
+
+  const zeroResult = (message: string, action: 'skipped-auto-grab-off' | 'skipped-no-source') => {
+    logger.info(message, { action });
+    return {
+      success: true,
+      message,
+      scanned: 0,
+      gapsFound: 0,
+      triggered: 0,
+      created: 0,
+      retried: 0,
+      skippedInFlight: 0,
+      skippedCancelled: 0,
+      skippedCapHit: 0,
+    };
+  };
+
+  try {
+    const configService = getConfigService();
+
+    // Gate #1 — auto-grab feature toggle
+    // Default ON when key is absent/null (matches organize-files.processor.ts).
+    const autoGrab = await configService.get('ebook_auto_grab_enabled');
+    if (autoGrab === 'false') {
+      return zeroResult('Auto-grab disabled, skipping', 'skipped-auto-grab-off');
+    }
+
+    // Gate #2 — at least one ebook source enabled
+    // Includes legacy back-compat shim: ebook_sidecar_enabled === 'true' counts
+    // as Anna's Archive ON if the new key is absent (mirrors manual fetch route).
+    const [annasArchive, indexerSearch, legacy] = await Promise.all([
+      configService.get('ebook_annas_archive_enabled'),
+      configService.get('ebook_indexer_search_enabled'),
+      configService.get('ebook_sidecar_enabled'),
+    ]);
+    const annasOn = annasArchive === 'true' || (annasArchive == null && legacy === 'true');
+    const indexerOn = indexerSearch === 'true';
+    if (!annasOn && !indexerOn) {
+      return zeroResult('No ebook sources enabled, skipping', 'skipped-no-source');
+    }
+
+    // Anti-join: most-recent non-deleted ebook child per in-scope audiobook.
+    // Broad form — branch fully in JS so per-skip counters and log lines are
+    // observable. LIMIT is the per-run scan cap.
+    const candidates = await prisma.$queryRaw<CandidateRow[]>`
+      SELECT
+        p.id                  AS parent_request_id,
+        p.user_id             AS user_id,
+        p.audiobook_id        AS audiobook_id,
+        p.custom_search_terms AS custom_search_terms,
+        a.title               AS audiobook_title,
+        a.author              AS audiobook_author,
+        a.audible_asin        AS audible_asin,
+        e.id                  AS ebook_request_id,
+        e.status              AS ebook_status,
+        e.ebook_auto_retry_count AS ebook_auto_retry_count
+      FROM requests p
+      JOIN audiobooks a ON a.id = p.audiobook_id
+      LEFT JOIN LATERAL (
+        SELECT id, status, ebook_auto_retry_count
+        FROM requests
+        WHERE parent_request_id = p.id
+          AND type = 'ebook'
+          AND deleted_at IS NULL
+        ORDER BY created_at DESC
+        LIMIT 1
+      ) e ON TRUE
+      WHERE p.status IN ('downloaded', 'available')
+        AND (p.type IS NULL OR p.type <> 'ebook')
+        AND p.deleted_at IS NULL
+      ORDER BY p.created_at DESC
+      LIMIT ${PER_RUN_LIMIT}
+    `;
+
+    const scanned = candidates.length;
+    logger.info(`Scanned ${scanned} in-scope audiobook request(s)`);
+
+    if (scanned === 0) {
+      return {
+        success: true,
+        message: 'No in-scope audiobook requests',
+        scanned: 0,
+        gapsFound: 0,
+        triggered: 0,
+        created: 0,
+        retried: 0,
+        skippedInFlight: 0,
+        skippedCancelled: 0,
+        skippedCapHit: 0,
+      };
+    }
+
+    const jobQueue = getJobQueueService();
+    let gapsFound = 0;
+    let created = 0;
+    let retried = 0;
+    let skippedInFlight = 0;
+    let skippedCancelled = 0;
+    let skippedCapHit = 0;
+
+    for (const row of candidates) {
+      let action:
+        | 'created'
+        | 'retried'
+        | 'skipped-has-companion'
+        | 'skipped-in-flight'
+        | 'skipped-cancelled'
+        | 'skipped-cap'
+        | 'skipped-unknown'
+        | null = null;
+      let ebookRequestId: string | null = row.ebook_request_id;
+
+      try {
+        await prisma.$transaction(async (tx) => {
+          if (!row.ebook_request_id) {
+            // No live ebook child — create one and seed counter at 1.
+            const createdRow = await tx.request.create({
+              data: {
+                userId: row.user_id,
+                audiobookId: row.audiobook_id,
+                type: 'ebook',
+                parentRequestId: row.parent_request_id,
+                status: 'pending',
+                progress: 0,
+                customSearchTerms: row.custom_search_terms,
+                ebookAutoRetryCount: 1,
+              },
+            });
+            ebookRequestId = createdRow.id;
+            action = 'created';
+            return;
+          }
+
+          const status = row.ebook_status;
+          if (status === 'downloaded') {
+            action = 'skipped-has-companion';
+            return;
+          }
+          if (status && IN_FLIGHT_STATUSES.has(status)) {
+            action = 'skipped-in-flight';
+            return;
+          }
+          if (status === 'cancelled') {
+            action = 'skipped-cancelled';
+            return;
+          }
+          if (status === 'failed' || status === 'warn') {
+            const current = row.ebook_auto_retry_count ?? 0;
+            if (current >= AUTO_RETRY_CAP) {
+              action = 'skipped-cap';
+              return;
+            }
+            await tx.request.update({
+              where: { id: row.ebook_request_id! },
+              data: {
+                status: 'pending',
+                progress: 0,
+                errorMessage: null,
+                ebookAutoRetryCount: current + 1,
+              },
+            });
+            action = 'retried';
+            return;
+          }
+          // Defensive — unrecognized status (e.g. denied, awaiting_import on an
+          // ebook child that crossed wires). Leave it alone; surface via log.
+          action = 'skipped-unknown';
+        });
+
+        if (action === 'created' || action === 'retried') {
+          gapsFound++;
+          try {
+            await jobQueue.addSearchEbookJob(ebookRequestId!, {
+              id: row.audiobook_id,
+              title: row.audiobook_title,
+              author: row.audiobook_author,
+              asin: row.audible_asin || undefined,
+            });
+            if (action === 'created') created++;
+            else retried++;
+          } catch (enqueueErr) {
+            // Roll counter back on enqueue failure so the cap reflects only
+            // successful auto-retries. Per engineering brief: "increment only
+            // when queue add succeeds." Failure to decrement is logged but
+            // swallowed — primary error is the one that matters.
+            await prisma.request.update({
+              where: { id: ebookRequestId! },
+              data: { ebookAutoRetryCount: { decrement: 1 } },
+            }).catch((rollbackErr) => {
+              logger.error(`Failed to roll back counter for ebook ${ebookRequestId}: ${rollbackErr instanceof Error ? rollbackErr.message : 'Unknown error'}`);
+            });
+            throw enqueueErr;
+          }
+        } else if (action === 'skipped-in-flight') skippedInFlight++;
+        else if (action === 'skipped-cancelled') skippedCancelled++;
+        else if (action === 'skipped-cap') skippedCapHit++;
+
+        logger.info('find_missing_ebooks iteration', {
+          audiobookId: row.audiobook_id,
+          parentRequestId: row.parent_request_id,
+          ebookRequestId,
+          action,
+        });
+      } catch (err) {
+        logger.error(`Failed candidate ${row.parent_request_id}: ${err instanceof Error ? err.message : 'Unknown error'}`);
+      }
+
+      // Spread DB operations over time to avoid connection pool exhaustion.
+      await new Promise((resolve) => setTimeout(resolve, 100));
+    }
+
+    const triggered = created + retried;
+    logger.info('find_missing_ebooks pass complete', {
+      scanned,
+      gapsFound,
+      triggered,
+      created,
+      retried,
+      skippedInFlight,
+      skippedCancelled,
+      skippedCapHit,
+    });
+
+    return {
+      success: true,
+      message: 'find_missing_ebooks completed',
+      scanned,
+      gapsFound,
+      triggered,
+      created,
+      retried,
+      skippedInFlight,
+      skippedCancelled,
+      skippedCapHit,
+    };
+  } catch (error) {
+    logger.error(`Error: ${error instanceof Error ? error.message : 'Unknown error'}`);
+    throw error;
+  }
+}

src/lib/services/job-queue.service.ts

@@ -24,6 +24,7 @@ export type JobType =
   | 'audible_refresh'
   | 'retry_missing_torrents'
   | 'retry_failed_imports'
+  | 'find_missing_ebooks'
   | 'cleanup_seeded_torrents'
   | 'monitor_rss_feeds'
   | 'sync_reading_shelves'
@@ -105,6 +106,10 @@ export interface RetryFailedImportsPayload extends JobPayload {
   scheduledJobId?: string;
 }
 
+export interface FindMissingEbooksPayload extends JobPayload {
+  scheduledJobId?: string;
+}
+
 export interface CleanupSeededTorrentsPayload extends JobPayload {
   scheduledJobId?: string;
 }
@@ -386,6 +391,12 @@ export class JobQueueService {
       return await processRetryFailedImports(payloadWithJobId);
     });
 
+    this.queue.process('find_missing_ebooks', 1, async (job: BullJob<FindMissingEbooksPayload>) => {
+      const { processFindMissingEbooks } = await import('../processors/find-missing-ebooks.processor');
+      const payloadWithJobId = await this.ensureJobRecord(job, 'find_missing_ebooks');
+      return await processFindMissingEbooks(payloadWithJobId);
+    });
+
     this.queue.process('cleanup_seeded_torrents', 1, async (job: BullJob<CleanupSeededTorrentsPayload>) => {
       const { processCleanupSeededTorrents } = await import('../processors/cleanup-seeded-torrents.processor');
       const payloadWithJobId = await this.ensureJobRecord(job, 'cleanup_seeded_torrents');
@@ -756,6 +767,21 @@ export class JobQueueService {
     );
   }
 
+  /**
+   * Add find missing ebooks job
+   */
+  async addFindMissingEbooksJob(scheduledJobId?: string): Promise<string> {
+    return await this.addJob(
+      'find_missing_ebooks',
+      {
+        scheduledJobId,
+      } as FindMissingEbooksPayload,
+      {
+        priority: 7,
+      }
+    );
+  }
+
   /**
    * Add cleanup seeded torrents job
    */

src/lib/services/scheduler.service.ts

@@ -10,7 +10,7 @@ import { RMABLogger } from '../utils/logger';
 
 const logger = RMABLogger.create('Scheduler');
 
-export type ScheduledJobType = 'plex_library_scan' | 'plex_recently_added_check' | 'audible_refresh' | 'retry_missing_torrents' | 'retry_failed_imports' | 'cleanup_seeded_torrents' | 'monitor_rss_feeds' | 'sync_reading_shelves' | 'check_watched_lists';
+export type ScheduledJobType = 'plex_library_scan' | 'plex_recently_added_check' | 'audible_refresh' | 'retry_missing_torrents' | 'retry_failed_imports' | 'find_missing_ebooks' | 'cleanup_seeded_torrents' | 'monitor_rss_feeds' | 'sync_reading_shelves' | 'check_watched_lists';
 
 export interface ScheduledJob {
   id: string;
@@ -115,6 +115,13 @@ export class SchedulerService {
         enabled: true, // Enable by default
         payload: {},
       },
+      {
+        name: 'Find Missing Ebooks',
+        type: 'find_missing_ebooks' as ScheduledJobType,
+        schedule: '0 0 * * *', // Daily at midnight
+        enabled: true, // Enable by default; gated by ebook_auto_grab_enabled + source-enablement at run time
+        payload: {},
+      },
       {
         name: 'Cleanup Seeded Torrents',
         type: 'cleanup_seeded_torrents' as ScheduledJobType,
@@ -379,6 +386,9 @@ export class SchedulerService {
       case 'retry_failed_imports':
         bullJobId = await this.triggerRetryFailedImports(job);
         break;
+      case 'find_missing_ebooks':
+        bullJobId = await this.triggerFindMissingEbooks(job);
+        break;
       case 'cleanup_seeded_torrents':
         bullJobId = await this.triggerCleanupSeededTorrents(job);
         break;
@@ -645,6 +655,13 @@ export class SchedulerService {
     return await this.jobQueue.addRetryFailedImportsJob(job.id);
   }
 
+  /**
+   * Trigger find missing ebooks safety-net pass
+   */
+  private async triggerFindMissingEbooks(job: any): Promise<string> {
+    return await this.jobQueue.addFindMissingEbooksJob(job.id);
+  }
+
   /**
    * Trigger RSS feed monitoring
    */

tests/helpers/job-queue.ts

@@ -18,6 +18,7 @@ export const createJobQueueMock = () => ({
   addAudibleRefreshJob: vi.fn(),
   addRetryMissingTorrentsJob: vi.fn(),
   addRetryFailedImportsJob: vi.fn(),
+  addFindMissingEbooksJob: vi.fn(),
   addCleanupSeededTorrentsJob: vi.fn(),
   addNotificationJob: vi.fn().mockResolvedValue(undefined),
 });

tests/processors/find-missing-ebooks.processor.test.ts

@@ -0,0 +1,472 @@
+/**
+ * Component: Find Missing Ebooks Processor Tests
+ * Documentation: documentation/backend/services/scheduler.md
+ */
+
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { createPrismaMock } from '../helpers/prisma';
+import { createJobQueueMock } from '../helpers/job-queue';
+
+const prismaMock = createPrismaMock();
+const jobQueueMock = createJobQueueMock();
+const configMock = vi.hoisted(() => ({ get: vi.fn() }));
+
+vi.mock('@/lib/db', () => ({
+  prisma: prismaMock,
+}));
+
+vi.mock('@/lib/services/job-queue.service', () => ({
+  getJobQueueService: () => jobQueueMock,
+}));
+
+vi.mock('@/lib/services/config.service', () => ({
+  getConfigService: () => configMock,
+}));
+
+type CandidateRow = {
+  parent_request_id: string;
+  user_id: string;
+  audiobook_id: string;
+  custom_search_terms: string | null;
+  audiobook_title: string;
+  audiobook_author: string;
+  audible_asin: string | null;
+  ebook_request_id: string | null;
+  ebook_status: string | null;
+  ebook_auto_retry_count: number | null;
+};
+
+const baseRow = (overrides: Partial<CandidateRow> = {}): CandidateRow => ({
+  parent_request_id: 'parent-1',
+  user_id: 'user-1',
+  audiobook_id: 'audio-1',
+  custom_search_terms: null,
+  audiobook_title: 'Test Book',
+  audiobook_author: 'Test Author',
+  audible_asin: 'ASIN0001',
+  ebook_request_id: null,
+  ebook_status: null,
+  ebook_auto_retry_count: null,
+  ...overrides,
+});
+
+/**
+ * Default: all gates pass (auto-grab default ON when null; Anna's enabled).
+ * Tests that want a different gate state can override before calling.
+ */
+const installDefaultGates = () => {
+  configMock.get.mockImplementation(async (key: string) => {
+    switch (key) {
+      case 'ebook_auto_grab_enabled':
+        return null; // null/absent => ON
+      case 'ebook_annas_archive_enabled':
+        return 'true';
+      case 'ebook_indexer_search_enabled':
+        return 'false';
+      case 'ebook_sidecar_enabled':
+        return null;
+      default:
+        return null;
+    }
+  });
+};
+
+beforeEach(() => {
+  vi.clearAllMocks();
+  installDefaultGates();
+  // Default: $transaction runs the callback against the prismaMock surface.
+  prismaMock.$transaction.mockImplementation(async (fn: any) => fn(prismaMock));
+  // Default: each create call returns a stable ebook request id.
+  prismaMock.request.create.mockImplementation(async (args: any) => ({
+    id: 'new-ebook-1',
+    ...args.data,
+  }));
+  prismaMock.request.update.mockResolvedValue({});
+});
+
+describe('processFindMissingEbooks — gating', () => {
+  it('returns zeros when auto-grab is disabled (explicit false)', async () => {
+    configMock.get.mockImplementation(async (key: string) =>
+      key === 'ebook_auto_grab_enabled' ? 'false' : null
+    );
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: 'job-1' });
+
+    expect(result).toMatchObject({
+      success: true,
+      scanned: 0,
+      gapsFound: 0,
+      triggered: 0,
+      created: 0,
+      retried: 0,
+      skippedInFlight: 0,
+      skippedCancelled: 0,
+      skippedCapHit: 0,
+    });
+    expect(prismaMock.$queryRaw).not.toHaveBeenCalled();
+    expect(jobQueueMock.addSearchEbookJob).not.toHaveBeenCalled();
+  });
+
+  it('treats auto-grab unset (null) as ON and proceeds to source check', async () => {
+    configMock.get.mockImplementation(async (key: string) => {
+      switch (key) {
+        case 'ebook_auto_grab_enabled':
+          return null;
+        case 'ebook_annas_archive_enabled':
+          return 'true';
+        default:
+          return null;
+      }
+    });
+    prismaMock.$queryRaw.mockResolvedValue([]);
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: 'job-2' });
+
+    expect(result.scanned).toBe(0);
+    expect(prismaMock.$queryRaw).toHaveBeenCalledTimes(1);
+  });
+
+  it('returns zeros when both new source keys disabled AND no legacy key', async () => {
+    configMock.get.mockImplementation(async (key: string) => {
+      switch (key) {
+        case 'ebook_auto_grab_enabled':
+          return null;
+        case 'ebook_annas_archive_enabled':
+          return 'false';
+        case 'ebook_indexer_search_enabled':
+          return 'false';
+        case 'ebook_sidecar_enabled':
+          return null;
+        default:
+          return null;
+      }
+    });
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: 'job-3' });
+
+    expect(result.scanned).toBe(0);
+    expect(prismaMock.$queryRaw).not.toHaveBeenCalled();
+  });
+
+  it('legacy ebook_sidecar_enabled=true (with new keys absent) passes the source gate', async () => {
+    configMock.get.mockImplementation(async (key: string) => {
+      switch (key) {
+        case 'ebook_auto_grab_enabled':
+          return null;
+        case 'ebook_annas_archive_enabled':
+          return null;
+        case 'ebook_indexer_search_enabled':
+          return null;
+        case 'ebook_sidecar_enabled':
+          return 'true';
+        default:
+          return null;
+      }
+    });
+    prismaMock.$queryRaw.mockResolvedValue([]);
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: 'job-4' });
+
+    expect(result.scanned).toBe(0);
+    expect(prismaMock.$queryRaw).toHaveBeenCalledTimes(1);
+  });
+});
+
+describe('processFindMissingEbooks — fresh-gap creation', () => {
+  it('creates a new ebook request when no live ebook child exists (audiobook downloaded)', async () => {
+    prismaMock.$queryRaw.mockResolvedValue([
+      baseRow({
+        parent_request_id: 'parent-fresh',
+        user_id: 'user-x',
+        audiobook_id: 'audio-x',
+        audiobook_title: 'Fresh Book',
+        audiobook_author: 'Some Author',
+        audible_asin: 'B09ABCDEFG',
+        custom_search_terms: 'cst',
+      }),
+    ]);
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: 'job-5' });
+
+    expect(prismaMock.request.create).toHaveBeenCalledWith({
+      data: {
+        userId: 'user-x',
+        audiobookId: 'audio-x',
+        type: 'ebook',
+        parentRequestId: 'parent-fresh',
+        status: 'pending',
+        progress: 0,
+        customSearchTerms: 'cst',
+        ebookAutoRetryCount: 1,
+      },
+    });
+    expect(jobQueueMock.addSearchEbookJob).toHaveBeenCalledWith(
+      'new-ebook-1',
+      expect.objectContaining({
+        id: 'audio-x',
+        title: 'Fresh Book',
+        author: 'Some Author',
+        asin: 'B09ABCDEFG',
+      })
+    );
+    expect(result).toMatchObject({
+      scanned: 1,
+      gapsFound: 1,
+      triggered: 1,
+      created: 1,
+      retried: 0,
+      skippedInFlight: 0,
+      skippedCancelled: 0,
+      skippedCapHit: 0,
+    });
+  });
+
+  it('also creates for audiobook in `available` state (both statuses in scope)', async () => {
+    // The query is responsible for filtering by status; here we just confirm
+    // that the processor doesn't add a second status guard in JS that would
+    // reject a row coming back from SQL.
+    prismaMock.$queryRaw.mockResolvedValue([
+      baseRow({
+        parent_request_id: 'parent-available',
+        audiobook_title: 'Available Book',
+      }),
+    ]);
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: 'job-6' });
+
+    expect(result.created).toBe(1);
+    expect(prismaMock.request.create).toHaveBeenCalled();
+  });
+
+  it('omits asin when audiobook has no audibleAsin', async () => {
+    prismaMock.$queryRaw.mockResolvedValue([baseRow({ audible_asin: null })]);
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    await processFindMissingEbooks({ jobId: 'job-6b' });
+
+    expect(jobQueueMock.addSearchEbookJob).toHaveBeenCalledWith(
+      'new-ebook-1',
+      expect.objectContaining({ asin: undefined })
+    );
+  });
+});
+
+describe('processFindMissingEbooks — branch skips', () => {
+  it('skips when most-recent ebook child is already downloaded (defensive)', async () => {
+    prismaMock.$queryRaw.mockResolvedValue([
+      baseRow({
+        ebook_request_id: 'ebook-1',
+        ebook_status: 'downloaded',
+        ebook_auto_retry_count: 0,
+      }),
+    ]);
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: 'job-7' });
+
+    expect(prismaMock.request.create).not.toHaveBeenCalled();
+    expect(prismaMock.request.update).not.toHaveBeenCalled();
+    expect(jobQueueMock.addSearchEbookJob).not.toHaveBeenCalled();
+    // skipped-has-companion is intentionally not surfaced as its own counter —
+    // admin can derive from scanned - gapsFound - skippedInFlight - skippedCancelled - skippedCapHit.
+    expect(result).toMatchObject({
+      scanned: 1,
+      gapsFound: 0,
+      triggered: 0,
+      skippedInFlight: 0,
+      skippedCancelled: 0,
+      skippedCapHit: 0,
+    });
+  });
+
+  it.each([
+    'pending',
+    'awaiting_approval',
+    'searching',
+    'downloading',
+    'processing',
+    'awaiting_search',
+    'awaiting_release',
+  ])('skips when most-recent ebook child status is in-flight: %s', async (status) => {
+    prismaMock.$queryRaw.mockResolvedValue([
+      baseRow({ ebook_request_id: 'ebook-1', ebook_status: status }),
+    ]);
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: `job-inflight-${status}` });
+
+    expect(prismaMock.request.create).not.toHaveBeenCalled();
+    expect(prismaMock.request.update).not.toHaveBeenCalled();
+    expect(jobQueueMock.addSearchEbookJob).not.toHaveBeenCalled();
+    expect(result.skippedInFlight).toBe(1);
+    expect(result.gapsFound).toBe(0);
+  });
+
+  it('skips when most-recent ebook child status is cancelled', async () => {
+    prismaMock.$queryRaw.mockResolvedValue([
+      baseRow({ ebook_request_id: 'ebook-1', ebook_status: 'cancelled' }),
+    ]);
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: 'job-cancelled' });
+
+    expect(jobQueueMock.addSearchEbookJob).not.toHaveBeenCalled();
+    expect(result.skippedCancelled).toBe(1);
+  });
+});
+
+describe('processFindMissingEbooks — retry path', () => {
+  it('retries a failed ebook child with counter < cap, increments counter', async () => {
+    prismaMock.$queryRaw.mockResolvedValue([
+      baseRow({
+        ebook_request_id: 'ebook-fail-1',
+        ebook_status: 'failed',
+        ebook_auto_retry_count: 3,
+      }),
+    ]);
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: 'job-retry' });
+
+    expect(prismaMock.request.update).toHaveBeenCalledWith({
+      where: { id: 'ebook-fail-1' },
+      data: {
+        status: 'pending',
+        progress: 0,
+        errorMessage: null,
+        ebookAutoRetryCount: 4,
+      },
+    });
+    expect(jobQueueMock.addSearchEbookJob).toHaveBeenCalledWith(
+      'ebook-fail-1',
+      expect.objectContaining({ id: 'audio-1' })
+    );
+    expect(result).toMatchObject({
+      retried: 1,
+      created: 0,
+      gapsFound: 1,
+      triggered: 1,
+      skippedCapHit: 0,
+    });
+  });
+
+  it('skips a warn ebook child whose counter is at the cap (5)', async () => {
+    prismaMock.$queryRaw.mockResolvedValue([
+      baseRow({
+        ebook_request_id: 'ebook-cap',
+        ebook_status: 'warn',
+        ebook_auto_retry_count: 5,
+      }),
+    ]);
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: 'job-cap' });
+
+    expect(prismaMock.request.update).not.toHaveBeenCalled();
+    expect(jobQueueMock.addSearchEbookJob).not.toHaveBeenCalled();
+    expect(result.skippedCapHit).toBe(1);
+    expect(result.retried).toBe(0);
+  });
+
+  it('retries a failed ebook child with null counter, sets counter to 1', async () => {
+    prismaMock.$queryRaw.mockResolvedValue([
+      baseRow({
+        ebook_request_id: 'ebook-null-counter',
+        ebook_status: 'failed',
+        ebook_auto_retry_count: null,
+      }),
+    ]);
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: 'job-null' });
+
+    expect(prismaMock.request.update).toHaveBeenCalledWith({
+      where: { id: 'ebook-null-counter' },
+      data: {
+        status: 'pending',
+        progress: 0,
+        errorMessage: null,
+        ebookAutoRetryCount: 1,
+      },
+    });
+    expect(result.retried).toBe(1);
+  });
+});
+
+describe('processFindMissingEbooks — error isolation', () => {
+  it('rolls back the counter when addSearchEbookJob throws, then continues with next candidate', async () => {
+    // Two candidates: first one's enqueue will throw, second should still process.
+    prismaMock.$queryRaw.mockResolvedValue([
+      baseRow({
+        parent_request_id: 'parent-throw',
+        audiobook_id: 'audio-throw',
+        ebook_request_id: 'ebook-throw',
+        ebook_status: 'failed',
+        ebook_auto_retry_count: 2,
+      }),
+      baseRow({
+        parent_request_id: 'parent-ok',
+        audiobook_id: 'audio-ok',
+        ebook_request_id: 'ebook-ok',
+        ebook_status: 'failed',
+        ebook_auto_retry_count: 0,
+      }),
+    ]);
+
+    jobQueueMock.addSearchEbookJob
+      .mockRejectedValueOnce(new Error('queue blew up'))
+      .mockResolvedValueOnce('bull-job-id');
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: 'job-throw' });
+
+    // Counter rolled back on the throwing candidate:
+    expect(prismaMock.request.update).toHaveBeenCalledWith({
+      where: { id: 'ebook-throw' },
+      data: { ebookAutoRetryCount: { decrement: 1 } },
+    });
+    // Second candidate still processed:
+    expect(prismaMock.request.update).toHaveBeenCalledWith({
+      where: { id: 'ebook-ok' },
+      data: {
+        status: 'pending',
+        progress: 0,
+        errorMessage: null,
+        ebookAutoRetryCount: 1,
+      },
+    });
+    // gapsFound counts both attempted gaps; only the second succeeds in being triggered.
+    expect(result.gapsFound).toBe(2);
+    expect(result.retried).toBe(1);
+    expect(result.created).toBe(0);
+  });
+});
+
+describe('processFindMissingEbooks — return shape', () => {
+  it('exposes all observable counters in the result', async () => {
+    prismaMock.$queryRaw.mockResolvedValue([]);
+
+    const { processFindMissingEbooks } = await import('@/lib/processors/find-missing-ebooks.processor');
+    const result = await processFindMissingEbooks({ jobId: 'job-shape' });
+
+    expect(result).toEqual(
+      expect.objectContaining({
+        success: true,
+        scanned: 0,
+        gapsFound: 0,
+        triggered: 0,
+        created: 0,
+        retried: 0,
+        skippedInFlight: 0,
+        skippedCancelled: 0,
+        skippedCapHit: 0,
+      })
+    );
+  });
+});

tests/services/scheduler.service.test.ts

@@ -16,6 +16,7 @@ const jobQueueMock = vi.hoisted(() => ({
   addAudibleRefreshJob: vi.fn(),
   addRetryMissingTorrentsJob: vi.fn(),
   addRetryFailedImportsJob: vi.fn(),
+  addFindMissingEbooksJob: vi.fn(),
   addCleanupSeededTorrentsJob: vi.fn(),
   addMonitorRssFeedsJob: vi.fn(),
   addSyncShelvesJob: vi.fn(),
@@ -80,7 +81,7 @@ describe('SchedulerService', () => {
     const service = new SchedulerService();
     await service.start();
 
-    expect(prismaMock.scheduledJob.create).toHaveBeenCalledTimes(9);
+    expect(prismaMock.scheduledJob.create).toHaveBeenCalledTimes(10);
     expect(jobQueueMock.addRepeatableJob).toHaveBeenCalledWith(
       'audible_refresh',
       { scheduledJobId: 'job-1' },
@@ -289,6 +290,7 @@ describe('SchedulerService', () => {
     ['audible_refresh', 'addAudibleRefreshJob'],
     ['retry_missing_torrents', 'addRetryMissingTorrentsJob'],
     ['retry_failed_imports', 'addRetryFailedImportsJob'],
+    ['find_missing_ebooks', 'addFindMissingEbooksJob'],
     ['cleanup_seeded_torrents', 'addCleanupSeededTorrentsJob'],
     ['monitor_rss_feeds', 'addMonitorRssFeedsJob'],
     ['sync_reading_shelves', 'addSyncShelvesJob'],