From 983ba7c2e415a7764c8a081bb2c11f6efdbe6151 Mon Sep 17 00:00:00 2001
From: John Mizerek <mizerek@gmail.com>
Date: Tue, 3 Mar 2026 14:33:39 -0800
Subject: [PATCH] Fix image media type detection from content, not extension

Claude API rejects images when the declared media type doesn't
match the actual content. Now detects JPEG/PNG/GIF/WebP from
base64 magic bytes instead of trusting file extensions or
Content-Type headers.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 api/setup/analyzeMenuUrl.cfm | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/api/setup/analyzeMenuUrl.cfm b/api/setup/analyzeMenuUrl.cfm
index 660b872..5451623 100644
--- a/api/setup/analyzeMenuUrl.cfm
+++ b/api/setup/analyzeMenuUrl.cfm
@@ -916,14 +916,13 @@
                                 <cfset imgPath = zipImageFiles[imgIdx]>
                                 <cftry>
                                     <cfset imgContent = fileReadBinary(imgPath)>
-                                    <cfset imgExt = lCase(listLast(imgPath, "."))>
-                                    <cfset mediaType = "image/jpeg">
-                                    <cfif imgExt EQ "png"><cfset mediaType = "image/png">
-                                    <cfelseif imgExt EQ "gif"><cfset mediaType = "image/gif">
-                                    <cfelseif imgExt EQ "webp"><cfset mediaType = "image/webp">
-                                    </cfif>
-
                                     <cfset base64Img = toBase64(imgContent)>
+                                    <!--- Detect actual media type from content, not extension --->
+                                    <cfset mediaType = "image/jpeg">
+                                    <cfif left(base64Img, 4) EQ "iVBO"><cfset mediaType = "image/png">
+                                    <cfelseif left(base64Img, 6) EQ "R0lGOD"><cfset mediaType = "image/gif">
+                                    <cfelseif left(base64Img, 5) EQ "UklGR"><cfset mediaType = "image/webp">
+                                    </cfif>
                                     <cfset arrayAppend(response.steps, "Analyzing image: " & listLast(imgPath, "/\"))>
 
                                     <!--- Build Claude request for business info extraction --->
@@ -1195,6 +1194,12 @@
             <!--- Process the image if we got valid content --->
             <cfif imgBytes GT 5000>
                 <cfset base64Content = toBase64(imgContent)>
+                <!--- Detect actual media type from content, not extension/headers --->
+                <cfset mediaType = "image/jpeg">
+                <cfif left(base64Content, 4) EQ "iVBO"><cfset mediaType = "image/png">
+                <cfelseif left(base64Content, 6) EQ "R0lGOD"><cfset mediaType = "image/gif">
+                <cfelseif left(base64Content, 5) EQ "UklGR"><cfset mediaType = "image/webp">
+                </cfif>
 
                 <cfset imgSource = structNew()>
                 <cfset imgSource["type"] = "base64">