diff --git a/litellm/llms/vertex_ai/gemini/transformation.py b/litellm/llms/vertex_ai/gemini/transformation.py
index 41cead57739..1217c444c24 100644
--- a/litellm/llms/vertex_ai/gemini/transformation.py
+++ b/litellm/llms/vertex_ai/gemini/transformation.py
@@ -5,6 +5,7 @@ Why separate file? Make it easy to see how transformation works
 """
 import json
 import os
+import re
 from typing import TYPE_CHECKING, Dict, List, Literal, Optional, Tuple, Union, cast
 
 import httpx
@@ -208,7 +209,7 @@ def _process_gemini_media(
             return _apply_gemini_3_metadata(
                 part, model, media_resolution_enum, video_metadata
             )
-        elif "https://generativelanguage.googleapis.com/v1beta/files/" in image_url:
+        elif re.search(r"https://generativelanguage\.googleapis\.com/v[^/]+/files/", image_url):
             # Gemini Files API URI — mime type is already known by the API,
             # no need to resolve it from the URL (which would cause a 403).
             file_data = FileDataType(file_uri=image_url)
diff --git a/litellm/types/llms/vertex_ai.py b/litellm/types/llms/vertex_ai.py
index c49fc96a65b..c46b0d82d0e 100644
--- a/litellm/types/llms/vertex_ai.py
+++ b/litellm/types/llms/vertex_ai.py
@@ -17,9 +17,9 @@ class FunctionCall(TypedDict):
     args: Optional[dict]
 
 
-class FileDataType(TypedDict):
+class FileDataType(TypedDict, total=False):
     mime_type: str
-    file_uri: str  # the cloud storage uri of storing this file
+    file_uri: Required[str]  # the cloud storage uri of storing this file
 
 
 class BlobType(TypedDict, total=False):
diff --git a/tests/test_litellm/llms/bedrock/files/expected_bedrock_batch_completions.jsonl b/tests/test_litellm/llms/bedrock/files/expected_bedrock_batch_completions.jsonl
index c58963bb1de..8bb35ba95d7 100644
--- a/tests/test_litellm/llms/bedrock/files/expected_bedrock_batch_completions.jsonl
+++ b/tests/test_litellm/llms/bedrock/files/expected_bedrock_batch_completions.jsonl
@@ -1,2 +1,2 @@
-{"recordId": "request-1", "modelInput": {"messages": [{"role": "user", "content": [{"type": "text", "text": "Hello world!"}]}], "max_tokens": 10, "system": [{"type": "text", "text": "You are a helpful assistant."}], "anthropic_version": "bedrock-2023-05-31"}}
-{"recordId": "request-2", "modelInput": {"messages": [{"role": "user", "content": [{"type": "text", "text": "Hello world!"}]}], "max_tokens": 10, "system": [{"type": "text", "text": "You are an unhelpful assistant."}], "anthropic_version": "bedrock-2023-05-31"}}
+{"recordId": "request-1", "modelInput": {"messages": [{"role": "user", "content": [{"type": "text", "text": "Hello world!"}]}], "max_tokens": 10, "system": [{"type": "text", "text": "You are a helpful assistant."}], "anthropic_version": "bedrock-2023-05-31", "anthropic_beta": []}}
+{"recordId": "request-2", "modelInput": {"messages": [{"role": "user", "content": [{"type": "text", "text": "Hello world!"}]}], "max_tokens": 10, "system": [{"type": "text", "text": "You are an unhelpful assistant."}], "anthropic_version": "bedrock-2023-05-31", "anthropic_beta": []}}
diff --git a/tests/test_litellm/llms/vertex_ai/gemini/test_vertex_ai_gemini_transformation.py b/tests/test_litellm/llms/vertex_ai/gemini/test_vertex_ai_gemini_transformation.py
index 1f3841b6738..130d9c8e260 100644
--- a/tests/test_litellm/llms/vertex_ai/gemini/test_vertex_ai_gemini_transformation.py
+++ b/tests/test_litellm/llms/vertex_ai/gemini/test_vertex_ai_gemini_transformation.py
@@ -1849,3 +1849,5 @@ def test_process_gemini_media_files_api_uri_with_explicit_format():
 
     assert "file_data" in part
     assert part["file_data"]["file_uri"] == gemini_file_uri
+    # The Files API already knows the mime type; explicit format must NOT be forwarded.
+    assert part["file_data"].get("mime_type") is None