diff --git a/apps/expo/app/(app)/current-pack/[id].tsx b/apps/expo/app/(app)/current-pack/[id].tsx
index 0e0b28f5e3..f5fe095587 100644
--- a/apps/expo/app/(app)/current-pack/[id].tsx
+++ b/apps/expo/app/(app)/current-pack/[id].tsx
@@ -1,4 +1,3 @@
-import type { PackItem } from '@packrat/types';
 import {
   Avatar,
   AvatarFallback,
@@ -8,6 +7,7 @@ import {
 } from '@packrat/ui/nativewindui';
 import { userStore } from 'expo-app/features/auth/store';
 import { usePackDetailsFromStore } from 'expo-app/features/packs/hooks/usePackDetailsFromStore';
+import type { PackItem } from 'expo-app/features/packs/types';
 import { type CategorySummary, computeCategorySummaries } from 'expo-app/features/packs/utils';
 import { cn } from 'expo-app/lib/cn';
 import { useColorScheme } from 'expo-app/lib/hooks/useColorScheme';
@@ -192,10 +192,7 @@ export default function CurrentPackScreen() {
           <CustomList
             data={pack.items}
             keyExtractor={(_, index) => index.toString()}
-            renderItem={(item, index) => (
-              // safe-cast: Treaty response type has createdAt?: string but PackItem schema requires string
-              <ItemRow item={item as unknown as PackItem} index={index} />
-            )}
+            renderItem={(item, index) => <ItemRow item={item} index={index} />}
           />
         </View>
       </ScrollView>
diff --git a/packages/api/src/routes/catalog/index.ts b/packages/api/src/routes/catalog/index.ts
index 1de525fe62..dadd399b1d 100644
--- a/packages/api/src/routes/catalog/index.ts
+++ b/packages/api/src/routes/catalog/index.ts
@@ -241,17 +241,12 @@ export const catalogRoutes = new Elysia({ prefix: '/catalog' })
     async ({ body }) => {
       const db = createDb();
       const data = body;
-      if (!data.name || data.weight === undefined || data.weight === null || !data.weightUnit) {
-        return status(400, { error: 'name, weight, and weightUnit are required' });
-      }
-      if (data.weight <= 0) {
-        return status(400, { error: 'weight must be a positive number' });
-      }
       const { OPENAI_API_KEY, AI_PROVIDER, CLOUDFLARE_ACCOUNT_ID, CLOUDFLARE_AI_GATEWAY_ID, AI } =
         getEnv();
 
       if (!OPENAI_API_KEY) {
-        return status(500, { error: 'OpenAI API key not configured' });
+        // Configuration error: surface as a 500 with a clear message
+        throw new Error('Service unavailable: OpenAI API key not configured');
       }
 
       const embeddingText = getEmbeddingText(data);
@@ -434,14 +429,12 @@ export const catalogRoutes = new Elysia({ prefix: '/catalog' })
         throw new NotFoundError('Catalog item not found');
       }
       const data = body;
-      if (data.weight !== undefined && data.weight !== null && data.weight <= 0) {
-        return status(400, { error: 'weight must be a positive number' });
-      }
       const { OPENAI_API_KEY, AI_PROVIDER, CLOUDFLARE_ACCOUNT_ID, CLOUDFLARE_AI_GATEWAY_ID, AI } =
         getEnv();
 
       if (!OPENAI_API_KEY) {
-        return status(500, { error: 'OpenAI API key not configured' });
+        // Configuration error: surface as a 500 with a clear message
+        throw new Error('Service unavailable: OpenAI API key not configured');
       }
 
       const existingItem = await db.query.catalogItems.findFirst({
diff --git a/packages/api/src/routes/weather.ts b/packages/api/src/routes/weather.ts
index c6c5af2db1..4bc3c297dd 100644
--- a/packages/api/src/routes/weather.ts
+++ b/packages/api/src/routes/weather.ts
@@ -11,6 +11,7 @@ import {
   WeatherSearchQuerySchema,
 } from '@packrat/schemas/weather';
 import { Elysia, status } from 'elysia';
+import { ZodError } from 'zod';
 
 const WEATHER_API_BASE_URL = 'https://api.weatherapi.com/v1';
 
@@ -153,6 +154,11 @@ export const weatherRoutes = new Elysia({ prefix: '/weather' })
           },
         });
       } catch (error) {
+        if (error instanceof ZodError) {
+          const invalidPaths = error.errors.map((e) => e.path.join('.')).join(', ');
+          console.error('Weather forecast response failed schema validation:', error.errors);
+          throw new Error(`Weather forecast response failed schema validation at: ${invalidPaths}`);
+        }
         console.error('Error fetching weather forecast:', error);
         return status(500, { error: 'Internal server error', code: 'WEATHER_FORECAST_ERROR' });
       }
diff --git a/packages/schemas/src/catalog.ts b/packages/schemas/src/catalog.ts
index 0b91cafbc8..823daaf3b5 100644
--- a/packages/schemas/src/catalog.ts
+++ b/packages/schemas/src/catalog.ts
@@ -229,7 +229,7 @@ export const UpdateCatalogItemRequestSchema = z.object({
   name: z.string().min(1).max(255).optional(),
   productUrl: z.string().url().optional(),
   sku: z.string().optional(),
-  weight: z.number().optional(),
+  weight: z.number().positive().optional(),
   weightUnit: z.enum(WEIGHT_UNITS).optional(),
   description: z.string().optional(),
   categories: z.array(z.string()).optional(),