fix(kobo): fix device controller and service errors

2026-11-03 08:21:39 -06:00 · 2026-02-15 23:41:00 -06:00
parent 6865b07c79
commit 6721e99831
7 changed files with 258 additions and 29 deletions
@@ -5,7 +5,7 @@
    {
      "idx": 0,
      "version": "7",
-      "when": 1771265803603,
+      "when": 1771266812483,
      "tag": "0000_add_kobo_sync",
      "breakpoints": true
    }
@@ -5,6 +5,7 @@ import { IoAdapter } from '@nestjs/platform-socket.io';
 import { AppModule } from './app.module';
 import { GlobalExceptionFilter } from './common/filters/http-exception.filter';
 import { join } from 'path';
+import { Readable } from 'stream';
 import { drizzle } from 'drizzle-orm/node-postgres';
 import { migrate } from 'drizzle-orm/node-postgres/migrator';
 import { Pool } from 'pg';
@@ -16,7 +17,26 @@ async function bootstrap() {
  const pool = new Pool({ connectionString: process.env.DATABASE_URL });
  await migrate(drizzle(pool), { migrationsFolder: join(__dirname, '..', 'src', 'db', 'migrations') });
  await pool.end();
-  const app = await NestFactory.create<NestFastifyApplication>(AppModule, new FastifyAdapter({ logger: true }));
+
+  const adapter = new FastifyAdapter({ logger: true });
+  const app = await NestFactory.create<NestFastifyApplication>(AppModule, adapter);
+
+  // Kobo devices send Content-Type: application/json with empty bodies on GET/DELETE.
+  // Fastify's default JSON parser rejects empty bodies, so we inject '{}' before parsing.
+  const fastify = adapter.getInstance();
+  fastify.addHook('preParsing', (request, _reply, payload, done) => {
+    const ct = request.headers['content-type'] ?? '';
+    const isJson = ct.startsWith('application/json');
+    const isEmpty = request.headers['content-length'] === '0' || request.headers['content-length'] === undefined;
+    if (isJson && isEmpty) {
+      const fake = new Readable();
+      fake.push('{}');
+      fake.push(null);
+      done(null, fake);
+      return;
+    }
+    done(null, payload);
+  });

  app.useWebSocketAdapter(new IoAdapter(app));

@@ -14,6 +14,24 @@ import { KoboReadingStateService } from './services/kobo-reading-state.service';
 import { KoboThumbnailService } from './services/kobo-thumbnail.service';
 import { KoboDownloadService } from './services/kobo-download.service';
 import { KoboProxyService } from './services/kobo-proxy.service';
+import { KOBO_STORE_RESOURCES } from './kobo-store-resources';
+
+function buildBaseUrl(req: FastifyRequest): string {
+  const hasForwarded = req.headers['x-forwarded-host'] || req.headers['x-forwarded-port'] || req.headers['x-forwarded-proto'];
+  const proto = (req.headers['x-forwarded-proto'] as string | undefined) ?? req.protocol;
+  const headerHost = req.headers['x-forwarded-host'] ?? req.headers.host;
+  let host = headerHost ? (Array.isArray(headerHost) ? headerHost[0] : headerHost) : req.hostname;
+
+  if (!hasForwarded && !host.includes(':')) {
+    const localPort = req.socket?.localPort;
+    const isDefault = (proto === 'http' && localPort === 80) || (proto === 'https' && localPort === 443);
+    if (localPort && !isDefault) {
+      host = host + ':' + String(localPort);
+    }
+  }
+
+  return proto + '://' + host;
+}

@Controller('kobo/:deviceToken')
@Public()
@@ -40,29 +58,30 @@ export class KoboDeviceController {
    };
  }

+  @Post('v1/auth/refresh')
+  @HttpCode(HttpStatus.OK)
+  authRefresh(@Body() body: Record<string, unknown>) {
+    return {
+      AccessToken: randomUUID(),
+      RefreshToken: body.RefreshToken ?? randomUUID(),
+      TokenType: 'Bearer',
+      TrackingId: randomUUID(),
+    };
+  }
+
  @Get('v1/initialization')
  @Header('x-kobo-apitoken', 'e30=')
  initialization(@KoboDevice() device: KoboDeviceContext, @Req() req: FastifyRequest) {
-    const baseUrl = `${req.protocol}://${req.hostname}`;
+    const baseUrl = buildBaseUrl(req);
    const t = device.deviceToken;
-    return {
-      Resources: {
-        image_host: baseUrl,
-        image_url_template: `/api/kobo/${t}/v1/books/{ImageId}/thumbnail/{Width}/{Height}/false/image.jpg`,
-        image_url_quality_template: `/api/kobo/${t}/v1/books/{ImageId}/thumbnail/{Width}/{Height}/{Quality}/false/image.jpg`,
-        library_sync: `/api/kobo/${t}/v1/library/sync`,
-        library_items: `/api/kobo/${t}/v1/library/{RevisionId}`,
-        library_metadata: `/api/kobo/${t}/v1/library/{RevisionId}/metadata`,
-        library_prices: `/api/kobo/${t}/v1/library/{RevisionId}/prices`,
-        library_book_get: `/api/kobo/${t}/v1/library/{RevisionId}`,
-        sign_in_page: `${baseUrl}/api/kobo/${t}/v1/signin`,
-        userguide_host: `${baseUrl}/api/kobo/${t}`,
-        user_loyalty_benefits: `/api/kobo/${t}/v1/user/loyalty/benefits`,
-        giftcard_epd_redeem_url: `${baseUrl}/api/kobo/${t}/v1/giftcard/redeem`,
-        get_tests_endpoint: `/api/kobo/${t}/v1/analytics/gettests`,
-      },
-      BookEntitlementsUrl: `/api/kobo/${t}/v1/library/sync`,
+    const resources = {
+      ...KOBO_STORE_RESOURCES,
+      image_host: baseUrl,
+      image_url_template: `${baseUrl}/api/kobo/${t}/v1/books/{ImageId}/thumbnail/{Width}/{Height}/false/image.jpg`,
+      image_url_quality_template: `${baseUrl}/api/kobo/${t}/v1/books/{ImageId}/thumbnail/{Width}/{Height}/{Quality}/{IsGreyscale}/image.jpg`,
+      library_sync: `${baseUrl}/api/kobo/${t}/v1/library/sync`,
    };
+    return { Resources: resources };
  }

  @Post('v1/analytics/gettests')
@@ -85,7 +104,7 @@ export class KoboDeviceController {
    @Req() req: FastifyRequest,
    @Res() reply: FastifyReply,
  ) {
-    const baseUrl = `${req.protocol}://${req.hostname}`;
+    const baseUrl = buildBaseUrl(req);
    const settings = await this.settingsService.getSettings(user.id);
    const { entitlements, hasMore, syncToken } = await this.syncService.getDelta(
      user.id,
@@ -110,7 +129,7 @@ export class KoboDeviceController {
  ) {
    const id = parseInt(bookId, 10);
    if (isNaN(id)) return this.proxyService.forward(req, reply, device.deviceToken);
-    const baseUrl = `${req.protocol}://${req.hostname}`;
+    const baseUrl = buildBaseUrl(req);
    const metadata = await this.syncService.getBookMetadata(user.id, id, device.deviceToken, baseUrl);
    reply.send(metadata);
  }
@@ -0,0 +1,166 @@
+// prettier-ignore
+export const KOBO_STORE_RESOURCES: Record<string, unknown> = {
+  account_page: 'https://www.kobo.com/account/settings',
+  account_page_rakuten: 'https://my.rakuten.co.jp/',
+  add_device: 'https://storeapi.kobo.com/v1/user/add-device',
+  add_entitlement: 'https://storeapi.kobo.com/v1/library/{RevisionIds}',
+  affiliaterequest: 'https://storeapi.kobo.com/v1/affiliate',
+  assets: 'https://storeapi.kobo.com/v1/assets',
+  audiobook: 'https://storeapi.kobo.com/v1/products/audiobooks/{ProductId}',
+  audiobook_detail_page: 'https://www.kobo.com/{region}/{language}/audiobook/{slug}',
+  audiobook_get_credits: 'https://www.kobo.com/{region}/{language}/audiobooks/plans',
+  audiobook_landing_page: 'https://www.kobo.com/{region}/{language}/audiobooks',
+  audiobook_preview: 'https://storeapi.kobo.com/v1/products/audiobooks/{Id}/preview',
+  audiobook_purchase_withcredit: 'https://storeapi.kobo.com/v1/store/audiobook/{Id}',
+  audiobook_subscription_management: 'https://www.kobo.com/{region}/{language}/account/subscriptions',
+  audiobook_subscription_orange_deal_inclusion_url: 'https://authorize.kobo.com/inclusion',
+  audiobook_subscription_purchase: 'https://www.kobo.com/{region}/{language}/checkoutoption/21C6D938-934B-4A91-B979-E14D70B2F280',
+  audiobook_subscription_tiers: 'https://www.kobo.com/{region}/{language}/checkoutoption/21C6D938-934B-4A91-B979-E14D70B2F280',
+  authorproduct_recommendations: 'https://storeapi.kobo.com/v1/products/books/authors/recommendations',
+  autocomplete: 'https://storeapi.kobo.com/v1/products/autocomplete',
+  blackstone_header: { key: 'x-amz-request-payer', value: 'requester' },
+  book: 'https://storeapi.kobo.com/v1/products/books/{ProductId}',
+  book_detail_page: 'https://www.kobo.com/{region}/{language}/ebook/{slug}',
+  book_detail_page_rakuten: 'https://books.rakuten.co.jp/rk/{crossrevisionid}',
+  book_landing_page: 'https://www.kobo.com/ebooks',
+  book_subscription: 'https://storeapi.kobo.com/v1/products/books/subscriptions',
+  browse_history: 'https://storeapi.kobo.com/v1/user/browsehistory',
+  categories: 'https://storeapi.kobo.com/v1/categories',
+  categories_page: 'https://www.kobo.com/ebooks/categories',
+  category: 'https://storeapi.kobo.com/v1/categories/{CategoryId}',
+  category_featured_lists: 'https://storeapi.kobo.com/v1/categories/{CategoryId}/featured',
+  category_products: 'https://storeapi.kobo.com/v1/categories/{CategoryId}/products',
+  checkout_borrowed_book: 'https://storeapi.kobo.com/v1/library/borrow',
+  client_authd_referral: 'https://authorize.kobo.com/api/AuthenticatedReferral/client/v1/getLink',
+  configuration_data: 'https://storeapi.kobo.com/v1/configuration',
+  content_access_book: 'https://storeapi.kobo.com/v1/products/books/{ProductId}/access',
+  customer_care_live_chat: 'https://v2.zopim.com/widget/livechat.html?key=Y6gwUmnu4OATxN3Tli4Av9bYN319BTdO',
+  daily_deal: 'https://storeapi.kobo.com/v1/products/dailydeal',
+  deals: 'https://storeapi.kobo.com/v1/deals',
+  delete_entitlement: 'https://storeapi.kobo.com/v1/library/{Ids}',
+  delete_tag: 'https://storeapi.kobo.com/v1/library/tags/{TagId}',
+  delete_tag_items: 'https://storeapi.kobo.com/v1/library/tags/{TagId}/items/delete',
+  device_auth: 'https://storeapi.kobo.com/v1/auth/device',
+  device_refresh: 'https://storeapi.kobo.com/v1/auth/refresh',
+  dictionary_host: 'https://ereaderfiles.kobo.com',
+  discovery_host: 'https://discovery.kobobooks.com',
+  dropbox_link_account_poll: 'https://authorize.kobo.com/{region}/{language}/LinkDropbox',
+  dropbox_link_account_start: 'https://authorize.kobo.com/LinkDropbox/start',
+  eula_page: 'https://www.kobo.com/termsofuse?style=onestore',
+  ereaderdevices: 'https://storeapi.kobo.com/v2/products/EReaderDeviceFeeds',
+  exchange_auth: 'https://storeapi.kobo.com/v1/auth/exchange',
+  external_book: 'https://storeapi.kobo.com/v1/products/books/external/{Ids}',
+  facebook_sso_page: 'https://authorize.kobo.com/signin/provider/Facebook/login?returnUrl=http://kobo.com/',
+  featured_list: 'https://storeapi.kobo.com/v1/products/featured/{FeaturedListId}',
+  featured_lists: 'https://storeapi.kobo.com/v1/products/featured',
+  free_books_page: {
+    EN: 'https://www.kobo.com/{region}/{language}/p/free-ebooks',
+    FR: 'https://www.kobo.com/{region}/{language}/p/livres-gratuits',
+    IT: 'https://www.kobo.com/{region}/{language}/p/libri-gratuiti',
+    NL: 'https://www.kobo.com/{region}/{language}/List/bekijk-het-overzicht-van-gratis-ebooks/QpkkVWnUw8sxmgjSlCbJRg',
+    PT: 'https://www.kobo.com/{region}/{language}/p/livros-gratis',
+  },
+  fte_feedback: 'https://storeapi.kobo.com/v1/products/ftefeedback',
+  funnel_metrics: 'https://storeapi.kobo.com/v1/funnelmetrics',
+  get_download_keys: 'https://storeapi.kobo.com/v1/library/downloadkeys',
+  get_download_link: 'https://storeapi.kobo.com/v1/library/downloadlink',
+  get_tests_request: 'https://storeapi.kobo.com/v1/analytics/gettests',
+  giftcard_epd_redeem_url: 'https://www.kobo.com/{storefront}/{language}/redeem-ereader',
+  giftcard_redeem_url: 'https://www.kobo.com/{storefront}/{language}/redeem',
+  googledrive_link_account_start: 'https://authorize.kobo.com/{region}/{language}/linkcloudstorage/provider/google_drive',
+  gpb_flow_enabled: 'False',
+  help_page: 'https://www.kobo.com/help',
+  image_host: 'https://cdn.kobo.com/book-images/',
+  image_url_quality_template: 'https://cdn.kobo.com/book-images/{ImageId}/{Width}/{Height}/{Quality}/{IsGreyscale}/image.jpg',
+  image_url_template: 'https://cdn.kobo.com/book-images/{ImageId}/{Width}/{Height}/false/image.jpg',
+  instapaper_enabled: 'True',
+  instapaper_env_url: 'https://www.instapaper.com/api/kobo',
+  instapaper_link_account_start: 'https://authorize.kobo.com/{region}/{language}/linkinstapaper',
+  kobo_audiobooks_credit_redemption: 'True',
+  kobo_audiobooks_enabled: 'True',
+  kobo_audiobooks_orange_deal_enabled: 'True',
+  kobo_audiobooks_subscriptions_enabled: 'True',
+  kobo_display_price: 'True',
+  kobo_dropbox_link_account_enabled: 'True',
+  kobo_google_tax: 'False',
+  kobo_googledrive_link_account_enabled: 'True',
+  kobo_nativeborrow_enabled: 'True',
+  kobo_onedrive_link_account_enabled: 'False',
+  kobo_onestorelibrary_enabled: 'False',
+  kobo_privacyCentre_url: 'https://www.kobo.com/privacy',
+  kobo_redeem_enabled: 'True',
+  kobo_shelfie_enabled: 'False',
+  kobo_subscriptions_enabled: 'True',
+  kobo_superpoints_enabled: 'True',
+  kobo_wishlist_enabled: 'True',
+  library_book: 'https://storeapi.kobo.com/v1/user/library/books/{LibraryItemId}',
+  library_items: 'https://storeapi.kobo.com/v1/user/library',
+  library_metadata: 'https://storeapi.kobo.com/v1/library/{Ids}/metadata',
+  library_prices: 'https://storeapi.kobo.com/v1/user/library/previews/prices',
+  library_search: 'https://storeapi.kobo.com/v1/library/search',
+  library_sync: 'https://storeapi.kobo.com/v1/library/sync',
+  love_dashboard_page: 'https://www.kobo.com/{region}/{language}/kobosuperpoints',
+  love_points_redemption_page: 'https://www.kobo.com/{region}/{language}/KoboSuperPointsRedemption?productId={ProductId}',
+  magazine_landing_page: 'https://www.kobo.com/emagazines',
+  more_sign_in_options: 'https://authorize.kobo.com/signin?returnUrl=http://kobo.com/#allProviders',
+  notebooks: 'https://storeapi.kobo.com/api/internal/notebooks',
+  notifications_registration_issue: 'https://storeapi.kobo.com/v1/notifications/registration',
+  oauth_host: 'https://oauth.kobo.com',
+  password_retrieval_page: 'https://www.kobo.com/passwordretrieval.html',
+  personalizedrecommendations: 'https://storeapi.kobo.com/v2/users/personalizedrecommendations',
+  pocket_link_account_start: 'https://authorize.kobo.com/{region}/{language}/linkpocket',
+  post_analytics_event: 'https://storeapi.kobo.com/v1/analytics/event',
+  ppx_purchasing_url: 'https://purchasing.kobo.com',
+  privacy_page: 'https://www.kobo.com/privacypolicy?style=onestore',
+  product_nextread: 'https://storeapi.kobo.com/v1/products/{ProductIds}/nextread',
+  product_prices: 'https://storeapi.kobo.com/v1/products/{ProductIds}/prices',
+  product_recommendations: 'https://storeapi.kobo.com/v1/products/{ProductId}/recommendations',
+  product_reviews: 'https://storeapi.kobo.com/v1/products/{ProductIds}/reviews',
+  products: 'https://storeapi.kobo.com/v1/products',
+  productsv2: 'https://storeapi.kobo.com/v2/products',
+  provider_external_sign_in_page: 'https://authorize.kobo.com/ExternalSignIn/{providerName}?returnUrl=http://kobo.com/',
+  purchase_buy: 'https://www.kobo.com/checkoutoption/',
+  purchase_buy_templated: 'https://www.kobo.com/{region}/{language}/checkoutoption/{ProductId}',
+  quickbuy_checkout: 'https://storeapi.kobo.com/v1/store/quickbuy/{PurchaseId}/checkout',
+  quickbuy_create: 'https://storeapi.kobo.com/v1/store/quickbuy/purchase',
+  rakuten_token_exchange: 'https://storeapi.kobo.com/v1/auth/rakuten_token_exchange',
+  rating: 'https://storeapi.kobo.com/v1/products/{ProductId}/rating/{Rating}',
+  reading_services_host: 'https://readingservices.kobo.com',
+  reading_state: 'https://storeapi.kobo.com/v1/library/{Ids}/state',
+  redeem_interstitial_page: 'https://www.kobo.com',
+  registration_page: 'https://authorize.kobo.com/signup?returnUrl=http://kobo.com/',
+  related_items: 'https://storeapi.kobo.com/v1/products/{Id}/related',
+  remaining_book_series: 'https://storeapi.kobo.com/v1/products/books/series/{SeriesId}',
+  rename_tag: 'https://storeapi.kobo.com/v1/library/tags/{TagId}',
+  review: 'https://storeapi.kobo.com/v1/products/reviews/{ReviewId}',
+  review_sentiment: 'https://storeapi.kobo.com/v1/products/reviews/{ReviewId}/sentiment/{Sentiment}',
+  shelfie_recommendations: 'https://storeapi.kobo.com/v1/user/recommendations/shelfie',
+  sign_in_page: 'https://auth.kobobooks.com/ActivateOnWeb',
+  social_authorization_host: 'https://social.kobobooks.com:8443',
+  social_host: 'https://social.kobobooks.com',
+  store_home: 'www.kobo.com/{region}/{language}',
+  store_host: 'www.kobo.com',
+  store_newreleases: 'https://www.kobo.com/{region}/{language}/List/new-releases/961XUjtsU0qxkFItWOutGA',
+  store_search: 'https://www.kobo.com/{region}/{language}/Search?Query={query}',
+  store_top50: 'https://www.kobo.com/{region}/{language}/ebooks/Top',
+  subs_landing_page: 'https://www.kobo.com/{region}/{language}/plus',
+  subs_management_page: 'https://www.kobo.com/{region}/{language}/account/subscriptions',
+  subs_plans_page: 'https://www.kobo.com/{region}/{language}/plus/plans',
+  subs_purchase_buy_templated: 'https://www.kobo.com/{region}/{language}/Checkoutoption/{ProductId}/{TierId}',
+  subscription_publisher_price_page: 'https://www.kobo.com/{region}/{language}/subscriptionpublisherprice',
+  tag_items: 'https://storeapi.kobo.com/v1/library/tags/{TagId}/Items',
+  tags: 'https://storeapi.kobo.com/v1/library/tags',
+  taste_profile: 'https://storeapi.kobo.com/v1/products/tasteprofile',
+  terms_of_sale_page: 'https://authorize.kobo.com/{region}/{language}/terms/termsofsale',
+  update_accessibility_to_preview: 'https://storeapi.kobo.com/v1/library/{EntitlementIds}/preview',
+  use_one_store: 'True',
+  user_loyalty_benefits: 'https://storeapi.kobo.com/v1/user/loyalty/benefits',
+  user_platform: 'https://storeapi.kobo.com/v1/user/platform',
+  user_profile: 'https://storeapi.kobo.com/v1/user/profile',
+  user_ratings: 'https://storeapi.kobo.com/v1/user/ratings',
+  user_recommendations: 'https://storeapi.kobo.com/v1/user/recommendations',
+  user_reviews: 'https://storeapi.kobo.com/v1/user/reviews',
+  user_wishlist: 'https://storeapi.kobo.com/v1/user/wishlist',
+  userguide_host: 'https://ereaderfiles.kobo.com',
+  wishlist_page: 'https://www.kobo.com/{region}/{language}/account/wishlist',
+};
@@ -7,6 +7,7 @@ const FORWARD_HEADERS = [
  'accept',
  'accept-encoding',
  'accept-language',
+  'authorization',
  'content-type',
  'user-agent',
  'x-kobo-appversion',
@@ -35,10 +36,15 @@ export class KoboProxyService {
    }

    try {
+      let body: string | undefined;
+      if (!['GET', 'HEAD'].includes(req.method) && req.body != null) {
+        body = typeof req.body === 'string' ? req.body : JSON.stringify(req.body);
+      }
+
      const upstream = await fetch(targetUrl, {
        method: req.method,
        headers,
-        body: ['GET', 'HEAD'].includes(req.method) ? undefined : (req.body as string | undefined),
+        body,
      });

      reply.status(upstream.status);
@@ -48,8 +54,8 @@ export class KoboProxyService {
        }
      });

-      const body = await upstream.arrayBuffer();
-      reply.send(Buffer.from(body));
+      const responseBody = await upstream.arrayBuffer();
+      reply.send(Buffer.from(responseBody));
    } catch (err) {
      this.logger.warn(`Proxy failed for ${targetUrl}: ${(err as Error).message}`);
      reply.status(502).send({ message: 'Upstream Kobo API unavailable' });
@@ -2,7 +2,7 @@ import { Inject, Injectable } from '@nestjs/common';
 import { and, eq, isNull, or, sql } from 'drizzle-orm';
 import { NodePgDatabase } from 'drizzle-orm/node-postgres';

-import { DB } from '../../../db/db.module';
+import { DB } from '../../../db';
 import * as schema from '../../../db/schema';

 type Db = NodePgDatabase<typeof schema>;
@@ -25,6 +25,24 @@ export class KoboReadingStateService {
    const entitlementId = String(bookId);
    const now = new Date().toISOString();

+    const book = await this.db.query.books.findFirst({
+      where: eq(schema.books.id, bookId),
+      columns: { id: true },
+    });
+    if (!book) {
+      return {
+        RequestResult: 'Success',
+        UpdateResults: [
+          {
+            EntitlementId: entitlementId,
+            CurrentBookmarkResult: { Result: 'Ignored' },
+            StatisticsResult: { Result: 'Ignored' },
+            StatusInfoResult: { Result: 'Ignored' },
+          },
+        ],
+      };
+    }
+
    const created = (payload.Created as string | undefined) ?? now;
    const lastModified = (payload.LastModified as string | undefined) ?? now;
    const priorityTimestamp = (payload.PriorityTimestamp as string | undefined) ?? lastModified;
@@ -1,8 +1,8 @@
-import { BadRequestException, Inject, Injectable } from '@nestjs/common';
+import { BadRequestException, Inject, Injectable, InternalServerErrorException } from '@nestjs/common';
 import { eq, sql } from 'drizzle-orm';
 import { NodePgDatabase } from 'drizzle-orm/node-postgres';

-import { DB } from '../../../db/db.module';
+import { DB } from '../../../db';
 import * as schema from '../../../db/schema';

 type Db = NodePgDatabase<typeof schema>;
@@ -30,7 +30,7 @@ export class KoboSettingsService {
      row = inserted ?? (await this.db.query.koboSyncSettings.findFirst({ where: eq(schema.koboSyncSettings.userId, userId) }));
    }

-    if (!row) throw new Error('Failed to create kobo settings row');
+    if (!row) throw new InternalServerErrorException('Failed to create kobo settings row');
    return {
      readingThreshold: row.readingThreshold,
      finishedThreshold: row.finishedThreshold,