From 1028789b4b95188712806309eef3e7f3770a8c10 Mon Sep 17 00:00:00 2001
From: Hamjaster <87142882+Hamjaster@users.noreply.github.com>
Date: Tue, 4 Aug 2026 12:19:41 +0500
Subject: [PATCH] fix(anthropic): resolve capabilities for mantle-routed
 bedrock ids

bedrock/mantle/anthropic.claude-opus-5 and bedrock/us.anthropic.claude-opus-5
are the same underlying model, but they did not resolve the same capabilities.
The mantle route segment was missing from the prefixes the model-map candidate
walk strips, so the lookup never reached the anthropic.claude-opus-5 entry:

  model id                                  effort_param
  mantle/anthropic.claude-opus-5             False
  us.anthropic.claude-opus-5                 True

The Bedrock invoke path strips output_config when neither supports_output_config
nor the effort check passes, so a mantle-routed Opus 5 lost its effort and went
out with the legacy thinking.type=enabled shape, which Bedrock rejects. Only
reasoning_effort="none" got through, because that drops the thinking block
instead of fixing its shape.

Add bedrock/mantle/ and mantle/ to the candidate prefixes. This only affects
capability lookups; the wire model id still comes from
strip_bedrock_routing_prefix, so mantle request routing is untouched.
---
 litellm/llms/anthropic/common_utils.py        |  2 ++
 ...ations_anthropic_claude3_transformation.py | 28 +++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/litellm/llms/anthropic/common_utils.py b/litellm/llms/anthropic/common_utils.py
index 73d897c8d28..e84d7c25382 100644
--- a/litellm/llms/anthropic/common_utils.py
+++ b/litellm/llms/anthropic/common_utils.py
@@ -309,7 +309,9 @@ class AnthropicModelInfo(BaseLLMModelInfo):
         prefixes = (
             "bedrock/converse/",
             "bedrock/invoke/",
+            "bedrock/mantle/",
             "bedrock/",
+            "mantle/",
             "vertex_ai/",
         )
         deprefixed = tuple(model[len(p) :] for p in prefixes if model.startswith(p))
diff --git a/tests/test_litellm/llms/bedrock/chat/invoke_transformations/test_bedrock_chat_invoke_transformations_anthropic_claude3_transformation.py b/tests/test_litellm/llms/bedrock/chat/invoke_transformations/test_bedrock_chat_invoke_transformations_anthropic_claude3_transformation.py
index 4c4c0e17a38..9a11683f364 100644
--- a/tests/test_litellm/llms/bedrock/chat/invoke_transformations/test_bedrock_chat_invoke_transformations_anthropic_claude3_transformation.py
+++ b/tests/test_litellm/llms/bedrock/chat/invoke_transformations/test_bedrock_chat_invoke_transformations_anthropic_claude3_transformation.py
@@ -430,6 +430,34 @@ def test_output_config_forwarded_for_bedrock_chat_invoke_request():
     assert result["max_tokens"] == 100
 
 
+def test_output_config_forwarded_for_mantle_routed_model():
+    """A mantle-routed id must resolve the same capabilities as its us.* twin.
+
+    bedrock/mantle/anthropic.claude-opus-5 and bedrock/us.anthropic.claude-opus-5
+    are the same underlying model, but the mantle route segment was not among the
+    prefixes capability lookups strip, so supports_output_config and the effort
+    check both came back False and this path stripped output_config. The request
+    then went out with the legacy thinking.type=enabled shape, which Bedrock
+    rejects.
+    """
+    config = AmazonAnthropicClaudeConfig()
+
+    optional_params = {
+        "max_tokens": 100,
+        "output_config": {"effort": "high"},
+    }
+
+    result = config.transform_request(
+        model="mantle/anthropic.claude-opus-5",
+        messages=[{"role": "user", "content": "test"}],
+        optional_params=optional_params,
+        litellm_params={},
+        headers={},
+    )
+
+    assert result.get("output_config") == {"effort": "high"}
+
+
 def test_output_config_format_converted_for_bedrock_chat_invoke_request():
     """Bedrock Invoke chat path consumes ``output_config.format`` before forwarding."""
     config = AmazonAnthropicClaudeConfig()