diff --git a/packages/core/src/scrapers/ebay.ts b/packages/core/src/scrapers/ebay.ts
index 0d0afe0..924d266 100644
--- a/packages/core/src/scrapers/ebay.ts
+++ b/packages/core/src/scrapers/ebay.ts
@@ -274,7 +274,7 @@ function parseEbayListings(
           );
 
           // Filter to only elements that actually contain prices (not labels)
-          const actualPrices: HTMLElement[] = [];
+          const actualPrices: Element[] = [];
           for (const el of allPriceElements) {
             const text = el.textContent?.trim();
             if (text && EBAY_PRICE_TEXT_RE.test(text) && text.length < 50) {
@@ -301,11 +301,10 @@ function parseEbayListings(
 
             if (nonStrikethroughPrices.length > 0) {
               // Use the first non-strikethrough price (sale price)
-              priceElement = nonStrikethroughPrices[0];
+              priceElement = nonStrikethroughPrices[0] ?? null;
             } else {
               // Fallback: use the last price (likely the most current)
-              const lastPrice = actualPrices[actualPrices.length - 1];
-              priceElement = lastPrice;
+              priceElement = actualPrices[actualPrices.length - 1] ?? null;
             }
           }
         }
diff --git a/packages/core/src/scrapers/facebook.ts b/packages/core/src/scrapers/facebook.ts
index e3832b3..54412d6 100644
--- a/packages/core/src/scrapers/facebook.ts
+++ b/packages/core/src/scrapers/facebook.ts
@@ -86,7 +86,7 @@ interface FacebookMarketplaceItem {
   __typename: "GroupCommerceProductItem";
 
   // Listing content
-  marketplace_listing_title: string;
+  marketplace_listing_title?: string;
   redacted_description?: {
     text: string;
   };
@@ -99,7 +99,7 @@ interface FacebookMarketplaceItem {
   listing_price?: {
     amount: string;
     currency: string;
-    amount_with_offset: string;
+    amount_with_offset?: string;
   };
 
   // Location
@@ -127,9 +127,9 @@ interface FacebookMarketplaceItem {
 
   // Seller information
   marketplace_listing_seller?: {
-    __typename: "User";
-    id: string;
-    name: string;
+    __typename?: "User";
+    id?: string;
+    name?: string;
     profile_picture?: {
       uri: string;
     };
@@ -1321,6 +1321,14 @@ export async function fetchFacebookItem(
     return null;
   }
 
+  if (itemResponseUrl.includes("unavailable_product=1")) {
+    logExtractionMetrics(false, itemId);
+    console.warn(
+      `Item ${itemId} appears to be sold or removed from marketplace.`,
+    );
+    return null;
+  }
+
   const itemData = extractFacebookItemData(itemHtml);
 
   if (classification.unavailable && !itemData) {
diff --git a/packages/core/src/utils/http.ts b/packages/core/src/utils/http.ts
index 3bd6e1e..b2b4796 100644
--- a/packages/core/src/utils/http.ts
+++ b/packages/core/src/utils/http.ts
@@ -1,56 +1,53 @@
 /** Custom error class for HTTP-related failures */
 export class HttpError extends Error {
+  override name = "HttpError";
   constructor(
     message: string,
     public readonly statusCode: number,
     public readonly url?: string,
   ) {
     super(message);
-    this.name = "HttpError";
   }
 }
 
 /** Error class for network failures (timeouts, connection issues) */
 export class NetworkError extends Error {
+  override name = "NetworkError";
   constructor(
     message: string,
     public readonly url: string,
-    public readonly cause?: Error,
+    public override readonly cause?: Error,
   ) {
     super(message);
-    this.name = "NetworkError";
   }
 }
 
 /** Error class for parsing failures */
 export class ParseError extends Error {
+  override name = "ParseError";
   constructor(
     message: string,
     public readonly data?: unknown,
   ) {
     super(message);
-    this.name = "ParseError";
   }
 }
 
 /** Error class for rate limiting */
 export class RateLimitError extends Error {
+  override name = "RateLimitError";
   constructor(
     message: string,
     public readonly url: string,
     public readonly resetTime?: number,
   ) {
     super(message);
-    this.name = "RateLimitError";
   }
 }
 
 /** Error class for validation failures */
 export class ValidationError extends Error {
-  constructor(message: string) {
-    super(message);
-    this.name = "ValidationError";
-  }
+  override name = "ValidationError";
 }
 
 /** Type guard to check if a value is a record (object) */
diff --git a/packages/core/src/utils/unstable.ts b/packages/core/src/utils/unstable.ts
index bffb606..d628ef5 100644
--- a/packages/core/src/utils/unstable.ts
+++ b/packages/core/src/utils/unstable.ts
@@ -1,21 +1,29 @@
-import type { ListingDetails, UnstableListingBuckets } from "../types/common";
+import type { UnstableListingBuckets } from "../types/common";
+
+interface HasListingPrice {
+  listingPrice?: { cents?: number } | null;
+}
 
 function getMedian(values: number[]): number {
   const middleIndex = Math.floor(values.length / 2);
 
   if (values.length % 2 === 0) {
-    return (values[middleIndex - 1] + values[middleIndex]) / 2;
+    const left = values[middleIndex - 1] ?? 0;
+    const right = values[middleIndex] ?? 0;
+    return (left + right) / 2;
   }
 
-  return values[middleIndex];
+  return values[middleIndex] ?? 0;
 }
 
-export function classifyUnstableListings<T extends ListingDetails>(
+export function classifyUnstableListings<T extends HasListingPrice>(
   listings: T[],
 ): UnstableListingBuckets<T> {
   const validPrices = listings
-    .map((listing) => listing.listingPrice.cents)
-    .filter((price) => Number.isFinite(price) && price > 0)
+    .map((listing) => listing.listingPrice?.cents)
+    .filter(
+      (price): price is number => Number.isFinite(price) && (price ?? 0) > 0,
+    )
     .sort((left, right) => left - right);
 
   if (validPrices.length < 2) {
@@ -32,9 +40,13 @@ export function classifyUnstableListings<T extends ListingDetails>(
   };
 
   for (const listing of listings) {
-    const price = listing.listingPrice.cents;
+    const price = listing.listingPrice?.cents;
 
-    if (Number.isFinite(price) && price > 0 && price < threshold) {
+    if (
+      Number.isFinite(price) &&
+      (price ?? 0) > 0 &&
+      (price ?? 0) < threshold
+    ) {
       buckets.unstableResults.push(listing);
       continue;
     }
diff --git a/packages/core/test/ebay-core.test.ts b/packages/core/test/ebay-core.test.ts
index df4cd2a..cc6cb05 100644
--- a/packages/core/test/ebay-core.test.ts
+++ b/packages/core/test/ebay-core.test.ts
@@ -34,7 +34,7 @@ describe("eBay Scraper Cookie Handling", () => {
         ok: true,
         text: () => Promise.resolve("<html><body></body></html>"),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
   });
 
   afterEach(() => {
@@ -51,7 +51,13 @@ describe("eBay Scraper Cookie Handling", () => {
 
     expect(global.fetch).toHaveBeenCalledTimes(1);
 
-    const [, init] = (global.fetch as ReturnType<typeof mock>).mock.calls[0];
+    const firstFetchCall = (global.fetch as unknown as ReturnType<typeof mock>)
+      .mock.calls[0];
+    if (!firstFetchCall) {
+      throw new Error("Expected fetch to be called");
+    }
+
+    const [, init] = firstFetchCall;
     const headers = (init as RequestInit).headers as Record<string, string>;
 
     expect(headers.Cookie).toBeUndefined();
@@ -75,7 +81,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("laptop", 1000);
 
@@ -100,7 +106,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("laptop", 1000);
 
@@ -130,7 +136,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("laptop", 1000);
 
@@ -167,7 +173,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("laptop", 1000);
 
@@ -199,7 +205,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("laptop", 1000);
 
@@ -225,7 +231,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("laptop", 1000);
 
@@ -254,7 +260,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("laptop", 1000);
 
@@ -283,7 +289,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("laptop", 1000);
 
@@ -317,7 +323,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("bundle", 1000, {
       keywords: ["bundle"],
@@ -357,7 +363,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("laptop", 1000);
 
@@ -389,7 +395,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("laptop", 1000);
 
@@ -421,7 +427,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("laptop", 1000);
 
@@ -451,7 +457,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("bike", 1000);
 
@@ -478,7 +484,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("microphone", 1000, {
       keywords: ["microphone"],
@@ -510,7 +516,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("laptop", 1000, {
       minPrice: 0,
@@ -550,7 +556,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems(
       "laptop",
@@ -595,7 +601,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems("laptop", 1000, { maxItems: 2 });
 
@@ -633,7 +639,7 @@ describe("eBay Scraper Cookie Handling", () => {
             </body></html>
           `),
       }),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
 
     const results = await fetchEbayItems(
       "laptop",
diff --git a/packages/core/test/facebook-core.test.ts b/packages/core/test/facebook-core.test.ts
index a262166..4dd4fea 100644
--- a/packages/core/test/facebook-core.test.ts
+++ b/packages/core/test/facebook-core.test.ts
@@ -52,7 +52,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
   beforeEach(() => {
     global.fetch = mock(() => {
       throw new Error("fetch should be mocked in individual tests");
-    });
+    }) as unknown as typeof fetch;
   });
 
   afterEach(() => {
@@ -93,8 +93,8 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
         const cookieString = "c_user=123%2B456; xs=abc%3Ddef";
         const result = parseFacebookCookieString(cookieString);
 
-        expect(result[0].value).toBe("123+456");
-        expect(result[1].value).toBe("abc=def");
+        expect(result[0]?.value).toBe("123+456");
+        expect(result[1]?.value).toBe("abc=def");
       });
 
       test("should filter out malformed cookies", () => {
@@ -115,10 +115,10 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
         const result = parseFacebookCookieString(cookieString);
 
         expect(result).toHaveLength(2);
-        expect(result[0].name).toBe("c_user");
-        expect(result[0].value).toBe("123");
-        expect(result[1].name).toBe("xs");
-        expect(result[1].value).toBe("abc");
+        expect(result[0]?.name).toBe("c_user");
+        expect(result[0]?.value).toBe("123");
+        expect(result[1]?.name).toBe("xs");
+        expect(result[1]?.value).toBe("abc");
       });
 
       test("should load Facebook cookies from FACEBOOK_COOKIE env var", async () => {
@@ -190,7 +190,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
               get: () => null,
             },
           }),
-        );
+        ) as unknown as typeof fetch;
 
         try {
           const result = await fetchFacebookItem("123");
@@ -214,7 +214,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
               get: () => null,
             },
           }),
-        );
+        ) as unknown as typeof fetch;
 
         const result = await fetchFacebookItem("nonexistent");
         expect(result).toBeNull();
@@ -274,7 +274,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
               get: () => null,
             },
           });
-        });
+        }) as unknown as typeof fetch;
 
         const _result = await fetchFacebookItem("123");
         expect(attempts).toBe(2);
@@ -297,7 +297,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
             },
             text: () => Promise.resolve("Rate limited"),
           });
-        });
+        }) as unknown as typeof fetch;
 
         const result = await fetchFacebookItem("429-loop");
 
@@ -346,7 +346,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
               get: () => null,
             },
           }),
-        );
+        ) as unknown as typeof fetch;
 
         const result = await fetchFacebookItem("456");
         expect(result?.listingStatus).toBe("SOLD");
@@ -388,7 +388,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
               get: () => null,
             },
           }),
-        );
+        ) as unknown as typeof fetch;
 
         const result = await fetchFacebookItem("457");
 
@@ -435,7 +435,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
               get: () => null,
             },
           }),
-        );
+        ) as unknown as typeof fetch;
 
         const result = await fetchFacebookItem("458");
 
@@ -493,7 +493,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
               get: () => null,
             },
           }),
-        );
+        ) as unknown as typeof fetch;
 
         const result = await fetchFacebookItem("789");
         expect(result).not.toBeNull();
@@ -512,7 +512,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
               get: () => null,
             },
           }),
-        );
+        ) as unknown as typeof fetch;
 
         const result = await fetchFacebookItem("error");
         expect(result).toBeNull();
@@ -573,7 +573,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("chair", 1, "toronto", 25);
 
@@ -618,7 +618,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("chair", 1, "toronto", 25);
 
@@ -682,7 +682,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
               get: () => null,
             },
           }),
-        );
+        ) as unknown as typeof fetch;
 
         const results = await fetchFacebookItems("chair", 1, "toronto", 25);
 
@@ -762,7 +762,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("chair", 1, "toronto", 25, {
         hideUnstableResults: true,
@@ -845,7 +845,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("chair", 1, "toronto", 2, {
         hideUnstableResults: true,
@@ -1132,7 +1132,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
         const result = extractFacebookMarketplaceData(html);
         expect(result).not.toBeNull();
         expect(result).toHaveLength(2);
-        expect(result?.[0].node.listing.marketplace_listing_title).toBe(
+        expect(result?.[0]?.node.listing.marketplace_listing_title).toBe(
           "Item 1",
         );
       });
@@ -1153,11 +1153,11 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
         const result = extractFacebookMarketplaceData(html);
         expect(result).not.toBeNull();
         expect(result).toHaveLength(1);
-        expect(result?.[0].node.listing.id).toBe("987654321");
-        expect(result?.[0].node.listing.marketplace_listing_title).toBe(
+        expect(result?.[0]?.node.listing.id).toBe("987654321");
+        expect(result?.[0]?.node.listing.marketplace_listing_title).toBe(
           "Vintage Bike",
         );
-        expect(result?.[0].node.listing.listing_price).toEqual({
+        expect(result?.[0]?.node.listing.listing_price).toEqual({
           amount: "120.00",
           formatted_amount: "CA$120",
           currency: "CAD",
@@ -1385,7 +1385,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
 
         const ads = extractFacebookMarketplaceData(html);
         expect(ads).toHaveLength(1);
-        expect(ads?.[0].node.listing.marketplace_listing_title).toBe("Bike");
+        expect(ads?.[0]?.node.listing.marketplace_listing_title).toBe("Bike");
       });
 
       test("prefers the strongest marketplace edge set when multiple edges arrays exist", () => {
@@ -1443,7 +1443,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
 
         const ads = extractFacebookMarketplaceData(html);
         expect(ads).toHaveLength(1);
-        expect(ads?.[0].node.listing.id).toBe("right-1");
+        expect(ads?.[0]?.node.listing.id).toBe("right-1");
       });
 
       test("rejects mixed edge arrays that contain non-listing entries", () => {
@@ -1668,11 +1668,11 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
 
         const results = parseFacebookAds(ads);
         expect(results).toHaveLength(2);
-        expect(results[0].title).toBe("Ad 1");
-        expect(results[0].listingPrice?.cents).toBe(5000);
-        expect(results[0].address).toBe("Toronto");
-        expect(results[1].title).toBe("Ad 2");
-        expect(results[1].address).toBe("Ottawa");
+        expect(results[0]?.title).toBe("Ad 1");
+        expect(results[0]?.listingPrice?.cents).toBe(5000);
+        expect(results[0]?.address).toBe("Toronto");
+        expect(results[1]?.title).toBe("Ad 2");
+        expect(results[1]?.address).toBe("Ottawa");
       });
 
       test("should filter out ads without price", () => {
@@ -1704,7 +1704,7 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
 
         const results = parseFacebookAds(ads);
         expect(results).toHaveLength(1);
-        expect(results[0].title).toBe("With Price");
+        expect(results[0]?.title).toBe("With Price");
       });
 
       test("should handle malformed ads gracefully", () => {
@@ -1731,12 +1731,14 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
             node: {
               // Missing listing
             },
-          } as { node: { listing?: unknown } },
+          } as unknown as { node: { listing?: unknown } },
         ];
 
-        const results = parseFacebookAds(ads);
+        const results = parseFacebookAds(
+          ads as unknown as Parameters<typeof parseFacebookAds>[0],
+        );
         expect(results).toHaveLength(1);
-        expect(results[0].title).toBe("Valid Ad");
+        expect(results[0]?.title).toBe("Valid Ad");
         expect(warnMock).toHaveBeenCalledTimes(1);
 
         console.warn = originalWarn;
diff --git a/packages/core/test/facebook-integration.test.ts b/packages/core/test/facebook-integration.test.ts
index a66ba19..dad5c7b 100644
--- a/packages/core/test/facebook-integration.test.ts
+++ b/packages/core/test/facebook-integration.test.ts
@@ -15,7 +15,7 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
     process.env.FACEBOOK_COOKIE = facebookCookie;
     global.fetch = mock(() => {
       throw new Error("fetch should be mocked in individual tests");
-    });
+    }) as unknown as typeof fetch;
   });
 
   afterEach(() => {
@@ -69,11 +69,11 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("iPhone", 1, "toronto", 25);
       expect(results).toHaveLength(1);
-      expect(results[0].title).toBe("iPhone 13");
+      expect(results[0]?.title).toBe("iPhone 13");
     });
 
     test("should filter out items without price", async () => {
@@ -135,11 +135,11 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("test", 1, "toronto", 25);
       expect(results).toHaveLength(1);
-      expect(results[0].title).toBe("With Price");
+      expect(results[0]?.title).toBe("With Price");
     });
 
     test("should respect MAX_ITEMS parameter", async () => {
@@ -190,7 +190,7 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("test", 1, "toronto", 5);
       expect(results).toHaveLength(5);
@@ -231,7 +231,7 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems(
         "nonexistent query",
@@ -252,7 +252,7 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("test", 1, "toronto", 25);
       expect(results).toEqual([]);
@@ -281,7 +281,7 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("lamp", 1, "toronto", 25);
       expect(results).toEqual([]);
@@ -322,14 +322,16 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("lamp", 1, "toronto", 25);
       expect(results).toEqual([]);
     });
 
     test("should handle network errors", async () => {
-      global.fetch = mock(() => Promise.reject(new Error("Network error")));
+      global.fetch = mock(() =>
+        Promise.reject(new Error("Network error")),
+      ) as unknown as typeof fetch;
 
       await expect(
         fetchFacebookItems("test", 1, "toronto", 25),
@@ -400,7 +402,7 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         });
-      });
+      }) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("test", 1, "toronto", 25);
       expect(attempts).toBe(2);
@@ -473,13 +475,13 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("cars", 1, "toronto", 25);
       expect(results).toHaveLength(2);
       // Both should be classified as "item" type in search results (vehicle detection is for item details)
-      expect(results[0].title).toBe("2006 Honda Civic");
-      expect(results[1].title).toBe("iPhone 13");
+      expect(results[0]?.title).toBe("2006 Honda Civic");
+      expect(results[1]?.title).toBe("iPhone 13");
     });
   });
 
@@ -542,7 +544,7 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems(
         "nintendo switch",
@@ -551,8 +553,8 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
         25,
       );
       expect(results).toHaveLength(1);
-      expect(results[0].title).toBe("Nintendo Switch");
-      expect(results[0].categoryId).toBe("479353692612078");
+      expect(results[0]?.title).toBe("Nintendo Switch");
+      expect(results[0]?.categoryId).toBe("479353692612078");
     });
 
     test("should handle home goods/furniture listings", async () => {
@@ -613,12 +615,12 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("table", 1, "toronto", 25);
       expect(results).toHaveLength(1);
-      expect(results[0].title).toBe("Dining Table");
-      expect(results[0].categoryId).toBe("1569171756675761");
+      expect(results[0]?.title).toBe("Dining Table");
+      expect(results[0]?.categoryId).toBe("1569171756675761");
     });
   });
 
@@ -635,7 +637,7 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("test", 1, "toronto", 25);
       expect(results).toEqual([]);
@@ -651,7 +653,7 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("test", 1, "toronto", 25);
       expect(results).toEqual([]);
@@ -667,7 +669,7 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const results = await fetchFacebookItems("test", 1, "toronto", 25);
       expect(results).toEqual([]);
@@ -708,7 +710,7 @@ describe("Facebook Marketplace Scraper Integration Tests", () => {
             get: () => null,
           },
         }),
-      );
+      ) as unknown as typeof fetch;
 
       const result = await fetchFacebookItem("123");
       expect(result).toBeNull();
diff --git a/packages/core/test/kijiji-core.test.ts b/packages/core/test/kijiji-core.test.ts
index 90c5f57..72e2488 100644
--- a/packages/core/test/kijiji-core.test.ts
+++ b/packages/core/test/kijiji-core.test.ts
@@ -49,7 +49,7 @@ const originalFetch = global.fetch;
 beforeEach(() => {
   global.fetch = mock(() => {
     throw new Error("fetch should be mocked in individual tests");
-  });
+  }) as unknown as typeof fetch;
 });
 
 afterEach(() => {
@@ -310,7 +310,7 @@ describe("fetchKijijiItems", () => {
       }
 
       throw new Error(`Unexpected URL: ${url}`);
-    }) as typeof fetch;
+    }) as unknown as typeof fetch;
 
     const results = await fetchKijijiItems(
       "phone",
@@ -418,7 +418,7 @@ describe("fetchKijijiItems", () => {
       }
 
       throw new Error(`Unexpected URL: ${url}`);
-    }) as typeof fetch;
+    }) as unknown as typeof fetch;
 
     const results = await fetchKijijiItems(
       "phone",
@@ -515,7 +515,7 @@ describe("fetchKijijiItems", () => {
       }
 
       throw new Error(`Unexpected URL: ${url}`);
-    }) as typeof fetch;
+    }) as unknown as typeof fetch;
 
     const results = await fetchKijijiItems(
       "phone",
@@ -628,7 +628,7 @@ describe("fetchKijijiItems", () => {
       }
 
       throw new Error(`Unexpected URL: ${url}`);
-    }) as typeof fetch;
+    }) as unknown as typeof fetch;
 
     const results = await fetchKijijiItems(
       "phone",
@@ -771,7 +771,7 @@ describe("fetchKijijiItems", () => {
       }
 
       throw new Error(`Unexpected URL: ${url}`);
-    }) as typeof fetch;
+    }) as unknown as typeof fetch;
 
     const results = await fetchKijijiItems(
       "phone",
@@ -872,7 +872,7 @@ describe("fetchKijijiItems", () => {
       }
 
       throw new Error(`Unexpected URL: ${url}`);
-    }) as typeof fetch;
+    }) as unknown as typeof fetch;
 
     await parseDetailedListing(html, "https://www.kijiji.ca", {
       includeClientSideData: true,
@@ -981,7 +981,7 @@ describe("fetchKijijiItems", () => {
       }
 
       throw new Error(`Unexpected URL: ${url}`);
-    }) as typeof fetch;
+    }) as unknown as typeof fetch;
 
     const results = await fetchKijijiItems(
       "phone",
diff --git a/packages/core/test/kijiji-integration.test.ts b/packages/core/test/kijiji-integration.test.ts
index 9195d0b..f638233 100644
--- a/packages/core/test/kijiji-integration.test.ts
+++ b/packages/core/test/kijiji-integration.test.ts
@@ -13,7 +13,7 @@ describe("HTML Parsing Integration", () => {
     // Mock fetch for all tests
     global.fetch = mock(() => {
       throw new Error("fetch should be mocked in individual tests");
-    });
+    }) as unknown as typeof fetch;
   });
 
   afterEach(() => {
@@ -111,7 +111,7 @@ describe("HTML Parsing Integration", () => {
 			`;
 
       const results = parseSearch(mockHtml, "https://www.kijiji.ca");
-      expect(results[0].listingLink).toBe(
+      expect(results[0]?.listingLink).toBe(
         "https://www.kijiji.ca/v-iphone/k0l0",
       );
     });
@@ -146,7 +146,7 @@ describe("HTML Parsing Integration", () => {
 
       const results = parseSearch(mockHtml, "https://www.kijiji.ca");
       expect(results).toHaveLength(1);
-      expect(results[0].name).toBe("iPhone 13 Pro");
+      expect(results[0]?.name).toBe("iPhone 13 Pro");
     });
 
     test("should return empty array for invalid HTML", () => {
diff --git a/packages/mcp-server/test/protocol.test.ts b/packages/mcp-server/test/protocol.test.ts
index e6ba98c..a137e9f 100644
--- a/packages/mcp-server/test/protocol.test.ts
+++ b/packages/mcp-server/test/protocol.test.ts
@@ -8,7 +8,7 @@ describe("MCP protocol cookie inputs", () => {
   beforeEach(() => {
     global.fetch = mock(() =>
       Promise.resolve(new Response(JSON.stringify([]), { status: 200 })),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
   });
 
   afterEach(() => {
@@ -48,7 +48,7 @@ describe("MCP protocol cookie inputs", () => {
       }),
     );
 
-    const calledUrl = (global.fetch as ReturnType<typeof mock>).mock
+    const calledUrl = (global.fetch as unknown as ReturnType<typeof mock>).mock
       .calls[0]?.[0];
     expect(String(calledUrl)).toContain("/facebook?q=laptop");
     expect(String(calledUrl)).not.toContain("cookies=");
@@ -59,7 +59,7 @@ describe("MCP protocol unstableFilter", () => {
   beforeEach(() => {
     global.fetch = mock(() =>
       Promise.resolve(new Response(JSON.stringify([]), { status: 200 })),
-    ) as typeof fetch;
+    ) as unknown as typeof fetch;
   });
 
   afterEach(() => {
@@ -103,7 +103,7 @@ describe("MCP protocol unstableFilter", () => {
       }),
     );
 
-    const calledUrl = (global.fetch as ReturnType<typeof mock>).mock
+    const calledUrl = (global.fetch as unknown as ReturnType<typeof mock>).mock
       .calls[0]?.[0];
     expect(String(calledUrl)).toContain("unstableFilter=true");
   });
@@ -127,7 +127,7 @@ describe("MCP protocol unstableFilter", () => {
       }),
     );
 
-    const calledUrl = (global.fetch as ReturnType<typeof mock>).mock
+    const calledUrl = (global.fetch as unknown as ReturnType<typeof mock>).mock
       .calls[0]?.[0];
     expect(String(calledUrl)).toContain("unstableFilter=true");
   });
@@ -151,7 +151,7 @@ describe("MCP protocol unstableFilter", () => {
       }),
     );
 
-    const calledUrl = (global.fetch as ReturnType<typeof mock>).mock
+    const calledUrl = (global.fetch as unknown as ReturnType<typeof mock>).mock
       .calls[0]?.[0];
     expect(String(calledUrl)).toContain("unstableFilter=true");
   });