diff --git a/server/src/index.ts b/server/src/index.ts
index 91e1177..fb1781e 100644
--- a/server/src/index.ts
+++ b/server/src/index.ts
@@ -44,7 +44,15 @@ const StoreItemSchema = z.object({
   category: z.string(),
   site: z.string(),
   batch: z.string(),
-  purchased: z.boolean(),
+  purchased: z.preprocess((v) => {
+    if (typeof v === 'string') {
+      const s = v.toLowerCase();
+      if (s === 'on' || s === 'true' || s === '1') return true;
+      if (s === 'off' || s === 'false' || s === '0') return false;
+    }
+    if (typeof v === 'number') return v === 1 ? true : v === 0 ? false : v;
+    return v;
+  }, z.boolean()),
   weight: z.number(),
   purchaseLink: z.string().optional()
 });