diff --git a/test/modules/types/message/initializeAttachmentMetadata_test.ts b/test/modules/types/message/initializeAttachmentMetadata_test.ts
new file mode 100644
index 0000000000..c6b69d1987
--- /dev/null
+++ b/test/modules/types/message/initializeAttachmentMetadata_test.ts
@@ -0,0 +1,50 @@
+import 'mocha';
+import { assert } from 'chai';
+
+import * as Message from '../../../../ts/types/message/initializeAttachmentMetadata';
+import { IncomingMessage } from '../../../../ts/types/Message';
+import { MIMEType } from '../../../../ts/types/MIME';
+// @ts-ignore
+import { stringToArrayBuffer } from '../../../../js/modules/string_to_array_buffer';
+
+
+describe('Message', () => {
+  describe('initializeAttachmentMetadata', () => {
+    it('should handle visual media attachments', async () => {
+      const input: IncomingMessage = {
+        type: 'incoming',
+        conversationId: 'foo',
+        id: '11111111-1111-1111-1111-111111111111',
+        timestamp: 1523317140899,
+        received_at: 1523317140899,
+        sent_at: 1523317140800,
+        attachments: [{
+          contentType: 'image/jpeg' as MIMEType,
+          data: stringToArrayBuffer('foo'),
+          fileName: 'foo.jpg',
+          size: 1111,
+        }],
+      };
+      const expected: IncomingMessage = {
+        type: 'incoming',
+        conversationId: 'foo',
+        id: '11111111-1111-1111-1111-111111111111',
+        timestamp: 1523317140899,
+        received_at: 1523317140899,
+        sent_at: 1523317140800,
+        attachments: [{
+          contentType: 'image/jpeg' as MIMEType,
+          data: stringToArrayBuffer('foo'),
+          fileName: 'foo.jpg',
+          size: 1111,
+        }],
+        numAttachments: 1,
+        numVisualMediaAttachments: 1,
+        numFileAttachments: 0,
+      };
+
+      const actual = await Message.initializeAttachmentMetadata(input);
+      assert.deepEqual(actual, expected);
+    });
+  });
+});
diff --git a/test/modules/types/message_test.js b/test/modules/types/message_test.js
index 271ffe825b..42e8c4c6c0 100644
--- a/test/modules/types/message_test.js
+++ b/test/modules/types/message_test.js
@@ -181,6 +181,9 @@ describe('Message', () => {
           fileName: 'test\uFFFDfig.exe',
           size: 1111,
         }],
+        numAttachments: 1,
+        numVisualMediaAttachments: 0,
+        numFileAttachments: 1,
         schemaVersion: Message.CURRENT_SCHEMA_VERSION,
       };
 
diff --git a/ts/types/message/initializeAttachmentMetadata.ts b/ts/types/message/initializeAttachmentMetadata.ts
new file mode 100644
index 0000000000..49d0f35d62
--- /dev/null
+++ b/ts/types/message/initializeAttachmentMetadata.ts
@@ -0,0 +1,20 @@
+import { partition } from 'lodash';
+
+import * as Attachment from '../Attachment';
+import { Message } from '../message';
+
+
+export const initializeAttachmentMetadata =
+  async (message: Message): Promise<Message> => {
+    const numAttachments = message.attachments.length;
+    const [numVisualMediaAttachments, numFileAttachments] =
+      partition(message.attachments, Attachment.isVisualMedia)
+        .map((attachments) => attachments.length);
+
+    return {
+      ...message,
+      numAttachments,
+      numVisualMediaAttachments,
+      numFileAttachments,
+    };
+  };