diff --git a/firestore-send-email/functions/__tests__/validation.test.ts b/firestore-send-email/functions/__tests__/validation.test.ts
index 1d74fca27..63aa6d8a4 100644
--- a/firestore-send-email/functions/__tests__/validation.test.ts
+++ b/firestore-send-email/functions/__tests__/validation.test.ts
@@ -615,7 +615,7 @@ describe("validatePayload", () => {
         };
         expect(() => validatePayload(invalidPayload)).toThrow(ValidationError);
         expect(() => validatePayload(invalidPayload)).toThrow(
-          "Invalid message configuration: Field 'message.attachments' must be an array"
+          "Invalid message configuration: Field 'message.attachments' must be an array. If you have a single attachment object, wrap it in an array (e.g., [{ filename: '...', path: '...' }])"
         );
       });
     });
diff --git a/firestore-send-email/functions/src/validation.ts b/firestore-send-email/functions/src/validation.ts
index 0d13af707..79923672c 100644
--- a/firestore-send-email/functions/src/validation.ts
+++ b/firestore-send-email/functions/src/validation.ts
@@ -53,7 +53,10 @@ export const attachmentSchema = z
   });
 
 export const attachmentsSchema = z
-  .array(attachmentSchema)
+  .array(attachmentSchema, {
+    invalid_type_error:
+      "Field 'attachments' must be an array. If you have a single attachment object, wrap it in an array (e.g., [{ filename: '...', path: '...' }])",
+  })
   .optional()
   .transform((attachments) =>
     attachments
@@ -182,10 +185,21 @@ function formatZodError(
     const path = issue.path.length > 0 ? issue.path.join(".") : context;
     switch (issue.code) {
       case "invalid_type":
+        if (issue.received === "undefined") {
+          return `Field '${path}' must be a ${issue.expected}`;
+        }
+
         if (issue.expected === "string") {
           return `Field '${path}' must be a string`;
         }
         if (issue.expected === "array") {
+          if (issue.message && !issue.message.startsWith("Expected")) {
+            const customMessage = issue.message.replace(
+              /Field 'attachments'/g,
+              `Field '${path}'`
+            );
+            return customMessage;
+          }
           return `Field '${path}' must be an array`;
         }
         if (issue.expected === "object") {
diff --git a/storage-resize-images/CHANGELOG.md b/storage-resize-images/CHANGELOG.md
index 0e7d219ff..f12933d6b 100644
--- a/storage-resize-images/CHANGELOG.md
+++ b/storage-resize-images/CHANGELOG.md
@@ -1,3 +1,8 @@
+## Version 0.3.1
+
+fix - add missing recordStartEvent call (#2546)
+feat - add new onStartResize event
+
 ## Version 0.3.0
 
 fix! - remove backfill, due to architectural flaws.
diff --git a/storage-resize-images/extension.yaml b/storage-resize-images/extension.yaml
index 69d3fec20..ea4fb4212 100644
--- a/storage-resize-images/extension.yaml
+++ b/storage-resize-images/extension.yaml
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 name: storage-resize-images
-version: 0.3.0
+version: 0.3.1
 specVersion: v1beta
 
 displayName: Resize Images
@@ -426,6 +426,12 @@ events:
     description:
       Occurs when the function is settled. Provides no customized data other
       than the context.
+
+  - type: firebase.extensions.storage-resize-images.v1.onStartResize
+    description:
+      Occurs when an image resize operation completes successfully. This event
+      is only triggered when shouldResize returns true and the resize operation
+      succeeds.
 # Lifecycle events disabled - backfill feature commented out
 # lifecycleEvents:
 #   onInstall:
diff --git a/storage-resize-images/functions/src/events.ts b/storage-resize-images/functions/src/events.ts
index f3168b4dc..6b548d766 100644
--- a/storage-resize-images/functions/src/events.ts
+++ b/storage-resize-images/functions/src/events.ts
@@ -60,3 +60,19 @@ export const recordCompletionEvent = async (data: string | object) => {
     data,
   });
 };
+
+export const recordStartResizeEvent = async ({
+  subject,
+  data,
+}: {
+  subject: string;
+  data: string | object;
+}) => {
+  if (!eventChannel) return;
+
+  return eventChannel.publish({
+    type: getEventType("onStartResize"),
+    subject,
+    data,
+  });
+};
diff --git a/storage-resize-images/functions/src/index.ts b/storage-resize-images/functions/src/index.ts
index 5cb7034f5..6a4a380cb 100644
--- a/storage-resize-images/functions/src/index.ts
+++ b/storage-resize-images/functions/src/index.ts
@@ -59,6 +59,11 @@ const generateResizedImageHandler = async (
     return;
   }
 
+  await events.recordStartResizeEvent({
+    subject: object.name,
+    data: { input: object },
+  });
+
   const bucket = admin.storage().bucket(object.bucket);
   const filePath = object.name; // File path in the bucket.
   const parsedPath = path.parse(filePath);
@@ -149,6 +154,7 @@ const generateResizedImageHandler = async (
 export const generateResizedImage = functions.storage
   .object()
   .onFinalize(async (object, context) => {
+    await events.recordStartEvent(object);
     await generateResizedImageHandler(object);
     await events.recordCompletionEvent({ context });
   });