From f04808e293669bb353158f69d6e75eda27a23db4 Mon Sep 17 00:00:00 2001
From: Ishaan Jaff <ishaanjaffer0324@gmail.com>
Date: Fri, 27 Jun 2025 15:49:07 -0700
Subject: [PATCH] [Bug Fix] Exception mapping for context window exceeded -
 should catch anthropic exceptions (#12113)

* fix is is_error_str_context_window_exceeded

* test_is_error_str_context_window_exceeded

* fix is_error_str_context_window_exceeded
---
 .../exception_mapping_utils.py                | 27 +++++++++++-----
 .../test_exception_mapping_utils.py           | 31 +++++++++++++++++++
 2 files changed, 51 insertions(+), 7 deletions(-)
 create mode 100644 tests/test_litellm/litellm_core_utils/test_exception_mapping_utils.py

diff --git a/litellm/litellm_core_utils/exception_mapping_utils.py b/litellm/litellm_core_utils/exception_mapping_utils.py
index f38883bb179..ad5060c533b 100644
--- a/litellm/litellm_core_utils/exception_mapping_utils.py
+++ b/litellm/litellm_core_utils/exception_mapping_utils.py
@@ -44,6 +44,25 @@ class ExceptionCheckers:
             return False
             
         return "429" in error_str or "rate limit" in error_str.lower()
+    
+
+    @staticmethod
+    def is_error_str_context_window_exceeded(error_str: str) -> bool:
+        """
+        Check if an error string indicates a context window exceeded error.
+        """
+        _error_str_lowercase = error_str.lower()
+        known_exception_substrings = [
+            "exceed context limit",
+            "this model's maximum context length is",
+            "string too long. expected a string with maximum length",
+            "model's maximum context limit",
+            "is longer than the model's context length",
+        ]
+        for substring in known_exception_substrings:
+            if substring in _error_str_lowercase:
+                return True
+        return False
 
 
 def get_error_message(error_obj) -> Optional[str]:
@@ -304,13 +323,7 @@ def exception_type(  # type: ignore  # noqa: PLR0915
                         llm_provider=custom_llm_provider,
                         response=getattr(original_exception, "response", None),
                     )
-                elif (
-                    "This model's maximum context length is" in error_str
-                    or "string too long. Expected a string with maximum length"
-                    in error_str
-                    or "model's maximum context limit" in error_str
-                    or "is longer than the model's context length" in error_str
-                ):
+                elif ExceptionCheckers.is_error_str_context_window_exceeded(error_str):
                     exception_mapping_worked = True
                     raise ContextWindowExceededError(
                         message=f"ContextWindowExceededError: {exception_provider} - {message}",
diff --git a/tests/test_litellm/litellm_core_utils/test_exception_mapping_utils.py b/tests/test_litellm/litellm_core_utils/test_exception_mapping_utils.py
new file mode 100644
index 00000000000..42e65612a96
--- /dev/null
+++ b/tests/test_litellm/litellm_core_utils/test_exception_mapping_utils.py
@@ -0,0 +1,31 @@
+import pytest
+
+from litellm.litellm_core_utils.exception_mapping_utils import ExceptionCheckers
+
+# Test cases for is_error_str_context_window_exceeded
+# Tuple format: (error_message, expected_result)
+context_window_test_cases = [
+    # Positive cases (should return True)
+    ("An error occurred: The input exceeds the model's maximum context limit of 8192 tokens.", True),
+    ("Some text before, this model's maximum context length is 4096 tokens. Some text after.", True),
+    ("Validation Error: string too long. expected a string with maximum length 1000.", True),
+    ("Your prompt is longer than the model's context length of 2048.", True),
+    ("AWS Bedrock Error: The request payload size has exceed context limit.", True),
+
+    # Test case insensitivity
+    ("ERROR: THIS MODEL'S MAXIMUM CONTEXT LENGTH IS 1024.", True),
+
+    # Negative cases (should return False)
+    ("A generic API error occurred.", False),
+    ("Invalid API Key provided.", False),
+    ("Rate limit reached for requests.", False),
+    ("The context is large, but acceptable.", False),
+    ("", False), # Empty string
+]
+
+@pytest.mark.parametrize("error_str, expected", context_window_test_cases)
+def test_is_error_str_context_window_exceeded(error_str, expected):
+    """
+    Tests the is_error_str_context_window_exceeded function with various error strings.
+    """
+    assert ExceptionCheckers.is_error_str_context_window_exceeded(error_str) == expected
\ No newline at end of file