From 0b3f3ed728d3435fb583d9a962e9974f3ad52d74 Mon Sep 17 00:00:00 2001
From: Siddharth Ganesan <siddharthganesan@gmail.com>
Date: Sat, 4 Apr 2026 17:04:14 -0700
Subject: [PATCH] File types

---
 apps/sim/lib/copilot/vfs/file-reader.ts | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/apps/sim/lib/copilot/vfs/file-reader.ts b/apps/sim/lib/copilot/vfs/file-reader.ts
index d3fd77aaf3..00f2e2dc55 100644
--- a/apps/sim/lib/copilot/vfs/file-reader.ts
+++ b/apps/sim/lib/copilot/vfs/file-reader.ts
@@ -31,6 +31,16 @@ function getExtension(filename: string): string {
   return dot >= 0 ? filename.slice(dot + 1).toLowerCase() : ''
 }
 
+function detectImageMime(buf: Buffer, claimed: string): string {
+  if (buf.length < 12) return claimed
+  if (buf[0] === 0xff && buf[1] === 0xd8 && buf[2] === 0xff) return 'image/jpeg'
+  if (buf[0] === 0x89 && buf[1] === 0x50 && buf[2] === 0x4e && buf[3] === 0x47) return 'image/png'
+  if (buf[0] === 0x47 && buf[1] === 0x49 && buf[2] === 0x46) return 'image/gif'
+  if (buf[8] === 0x57 && buf[9] === 0x45 && buf[10] === 0x42 && buf[11] === 0x50)
+    return 'image/webp'
+  return claimed
+}
+
 export interface FileReadResult {
   content: string
   totalLines: number
@@ -59,14 +69,15 @@ export async function readFileRecord(record: WorkspaceFileRecord): Promise<FileR
         }
       }
       const buffer = await downloadWorkspaceFile(record)
+      const mime = detectImageMime(buffer, record.type)
       return {
-        content: `Image: ${record.name} (${(record.size / 1024).toFixed(1)}KB, ${record.type})`,
+        content: `Image: ${record.name} (${(record.size / 1024).toFixed(1)}KB, ${mime})`,
         totalLines: 1,
         attachment: {
           type: 'image',
           source: {
             type: 'base64',
-            media_type: record.type,
+            media_type: mime,
             data: buffer.toString('base64'),
           },
         },