fix: openAI input image sanitization (#384)

Co-authored-by: Aleksander Błaszkiewicz <kqmdjc8@gmail.com>

Author: vikas5914

posthog/ai/sanitization.py

@@ -83,6 +83,12 @@ def sanitize_openai_image(item: Any) -> Any:
     if not isinstance(item, dict):
         return item
 
+    if item.get("type") == "input_image" and isinstance(item.get("image_url"), str):
+        return {
+            **item,
+            "image_url": redact_base64_data_url(item["image_url"]),
+        }
+
     if (
         item.get("type") == "image_url"
         and isinstance(item.get("image_url"), dict)

posthog/test/ai/test_sanitization.py

@@ -69,6 +69,25 @@ def test_sanitize_openai(self):
         )
         self.assertEqual(result[0]["content"][1]["image_url"]["detail"], "high")
 
+    def test_sanitize_openai_input_image(self):
+        input_data = [
+            {
+                "role": "user",
+                "content": [
+                    {
+                        "type": "input_image",
+                        "image_url": self.sample_base64_image,
+                    }
+                ],
+            }
+        ]
+
+        result = sanitize_openai(input_data)
+
+        self.assertEqual(
+            result[0]["content"][0]["image_url"], REDACTED_IMAGE_PLACEHOLDER
+        )
+
     def test_sanitize_openai_preserves_regular_urls(self):
         input_data = [
             {