From 3bbfe7e75da9d7e870376cbe19ae1a082fe07241 Mon Sep 17 00:00:00 2001
From: Anas Khan <83116240+anxkhn@users.noreply.github.com>
Date: Mon, 6 Jul 2026 18:35:25 +0530
Subject: [PATCH] fix(anthropic): guard file-id discovery against malformed
 content blocks

get_file_ids_from_messages iterated user message content and indexed
c["type"] with no check that each item is a dict or that the key exists.
Because AnthropicConfig.validate_environment calls it unconditionally via
is_file_id_used, a single malformed content block crashed request building
for every Anthropic, Bedrock-Claude, Vertex-Anthropic and Azure-AI-Anthropic
completion:

- a block dict missing "type" raised KeyError
- a non-dict list item (e.g. token-id lists forwarded by text_completion)
  raised TypeError: list indices must be integers
- a bare string item raised TypeError: string indices must be integers

Skip non-dict items and read "type" with .get(), mirroring the already
hardened sibling update_messages_with_model_file_ids in the same module.
Well-formed OpenAI file blocks still yield their file_id unchanged.

Signed-off-by: Anas Khan <83116240+anxkhn@users.noreply.github.com>
---
 .../prompt_templates/common_utils.py          |  4 ++-
 ...ore_utils_prompt_templates_common_utils.py | 26 +++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/litellm/litellm_core_utils/prompt_templates/common_utils.py b/litellm/litellm_core_utils/prompt_templates/common_utils.py
index 538d5f650ef..d2d32fe7c1c 100644
--- a/litellm/litellm_core_utils/prompt_templates/common_utils.py
+++ b/litellm/litellm_core_utils/prompt_templates/common_utils.py
@@ -1238,7 +1238,9 @@ def get_file_ids_from_messages(messages: List[AllMessageValues]) -> List[str]:
                 if isinstance(content, str):
                     continue
                 for c in content:
-                    if c["type"] == "file":
+                    if not isinstance(c, dict):
+                        continue
+                    if c.get("type") == "file":
                         file_object = cast(ChatCompletionFileObject, c)
                         file_object_file_field = file_object.get("file")
                         if not isinstance(file_object_file_field, dict):
diff --git a/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py b/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py
index 1b1db634ed2..7aa0d9898b2 100644
--- a/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py
+++ b/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py
@@ -343,6 +343,32 @@ def test_get_file_ids_from_messages_file_field_not_dict():
     assert get_file_ids_from_messages(messages) == []
 
 
+def test_get_file_ids_from_messages_content_block_without_type():
+    """A content block dict that omits `type` must not raise KeyError."""
+    messages = [
+        {
+            "role": "user",
+            "content": [
+                {"text": "hi"},
+                {"type": "file", "file": {"file_id": "file-keep"}},
+            ],
+        }
+    ]
+
+    assert get_file_ids_from_messages(messages) == ["file-keep"]
+
+
+def test_get_file_ids_from_messages_non_dict_content_items():
+    """Non-dict content items (e.g. token-id lists forwarded by
+    text_completion, or bare strings) must be skipped, not indexed into."""
+    messages = [
+        {"role": "user", "content": [[1, 2, 3]]},
+        {"role": "user", "content": ["hello"]},
+    ]
+
+    assert get_file_ids_from_messages(messages) == []
+
+
 def test_update_messages_with_model_file_ids_skips_non_openai_file_blocks():
     """`update_messages_with_model_file_ids` is also called on user content
     before provider dispatch. It must tolerate non-OpenAI file blocks the same