diff --git a/src/app/api/v1/stock-purchases/list/route.test.ts b/src/app/api/v1/stock-purchases/list/route.test.ts
index d4382b5..e4aaba2 100644
--- a/src/app/api/v1/stock-purchases/list/route.test.ts
+++ b/src/app/api/v1/stock-purchases/list/route.test.ts
@@ -93,4 +93,38 @@ describe("/api/v1/stock-purchases/list", () => {
     const body = await res.json();
     expect(body.error).toBe("PB is down");
   });
+
+  it("returns 401 when the request is not authenticated", async () => {
+    // No bearer header — assertAgentAuth throws with status: 401.
+    const req = new NextRequest("http://localhost/api/v1/stock-purchases/list");
+    const res = await GET(req);
+    expect(res.status).toBe(401);
+    expect(listStockPurchases).not.toHaveBeenCalled();
+  });
+
+  it("clamps page/perPage and falls back to defaults on malformed input", async () => {
+    listStockPurchases.mockResolvedValue({
+      items: [],
+      totalItems: 0,
+      page: 1,
+      perPage: 50,
+      totalPages: 0,
+    });
+
+    const cases: Array<[string, { status: ""; page: number; perPage: number }]> = [
+      ["?page=0", { status: "", page: 1, perPage: 50 }],
+      ["?page=abc", { status: "", page: 1, perPage: 50 }],
+      ["?perPage=0", { status: "", page: 1, perPage: 50 }],
+      ["?perPage=abc", { status: "", page: 1, perPage: 50 }],
+      ["?perPage=999", { status: "", page: 1, perPage: 200 }],
+    ];
+
+    for (const [qs, expected] of cases) {
+      listStockPurchases.mockClear();
+      await GET(
+        authedRequest(`http://localhost/api/v1/stock-purchases/list${qs}`),
+      );
+      expect(listStockPurchases).toHaveBeenCalledWith(expect.anything(), expected);
+    }
+  });
 });
diff --git a/src/app/api/v1/stock-purchases/list/route.ts b/src/app/api/v1/stock-purchases/list/route.ts
index c20b6da..0818caa 100644
--- a/src/app/api/v1/stock-purchases/list/route.ts
+++ b/src/app/api/v1/stock-purchases/list/route.ts
@@ -39,10 +39,16 @@ export async function GET(req: NextRequest) {
     }
     const status = rawStatus as StockPurchaseStatus | "";
 
-    const page = Math.max(1, Number(req.nextUrl.searchParams.get("page") || "1"));
+    const page = Math.max(
+      1,
+      Number(req.nextUrl.searchParams.get("page") || "1") || 1,
+    );
     const perPage = Math.min(
       200,
-      Math.max(1, Number(req.nextUrl.searchParams.get("perPage") || "50")),
+      Math.max(
+        1,
+        Number(req.nextUrl.searchParams.get("perPage") || "50") || 50,
+      ),
     );
 
     const pb = await getAdminPocketBase();
@@ -51,6 +57,7 @@ export async function GET(req: NextRequest) {
   } catch (error) {
     const message =
       error instanceof Error ? error.message : "Failed to fetch stock-purchases";
-    return NextResponse.json({ error: message }, { status: 500 });
+    const status = (error as Error & { status?: number }).status || 500;
+    return NextResponse.json({ error: message }, { status });
   }
 }