From a34f098fe5406b8bb9d2ec7b7a91c27131a55ee5 Mon Sep 17 00:00:00 2001
From: Abhimanyu Kapur <38531241+akapur99@users.noreply.github.com>
Date: Fri, 10 Jul 2026 21:16:17 -0700
Subject: [PATCH] docs(anthropic): clarify the Opus 4.5 branch in
 adaptive-effort translation

Add an inline comment explaining that the effort-capable non-adaptive branch in
_translate_adaptive_effort_for_non_adaptive_model exists for models like Claude Opus
4.5 that accept output_config.effort but reject adaptive thinking, and why effort-only
requests pass through while adaptive requests with an unsupported effort level fall
through to the legacy translation.
---
 .../experimental_pass_through/messages/transformation.py     | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/litellm/llms/anthropic/experimental_pass_through/messages/transformation.py b/litellm/llms/anthropic/experimental_pass_through/messages/transformation.py
index 39713e0f003..01412d3c8b2 100644
--- a/litellm/llms/anthropic/experimental_pass_through/messages/transformation.py
+++ b/litellm/llms/anthropic/experimental_pass_through/messages/transformation.py
@@ -329,6 +329,11 @@ class AnthropicMessagesConfig(BaseAnthropicMessagesConfig):
         if effort is None and not adaptive_thinking:
             return
 
+        # Models that natively accept `output_config.effort` but are not adaptive (Claude Opus 4.5).
+        # Keep the native effort and only drop the adaptive `thinking` block, which these models
+        # reject. Effort-only requests pass through so provider subclasses (bedrock/vertex) keep
+        # owning level clamping; an adaptive request only stays here when its effort level is one
+        # the model supports, otherwise it falls through to the legacy budget translation below.
         if AnthropicConfig._model_supports_effort_param(model, custom_llm_provider) and (
             not adaptive_thinking
             or AnthropicConfig._validate_effort_for_model(model, effort, custom_llm_provider) is None