fix(anthropic): allow output_config effort max for Opus 4.7 and model map

- Validate max effort like xhigh: Opus 4.6/4.7 id patterns or supports_max_reasoning_effort
- Set supports_max_reasoning_effort on claude-opus-4-7 entries in model cost JSON
- Update tests and add test_max_effort_accepted_for_opus_47

Made-with: Cursor

litellm/llms/anthropic/chat/transformation.py

@@ -1534,12 +1534,16 @@ class AnthropicConfig(AnthropicModelInfo, BaseConfig):
                 f"Invalid effort value: {effort}. Must be one of: "
                 f"'high', 'medium', 'low', 'xhigh', 'max'"
             )
-        # ``max`` is Claude Opus 4.6 only (not Sonnet 4.6, not Opus 4.5/4.7).
-        # Keep this hardcoded so the error message is specific and stable.
-        if effort == "max" and not self._is_opus_4_6_model(model):
+        # ``max`` is for Opus 4.6+ output effort (not Sonnet 4.6, not Opus 4.5).
+        # Accept known Opus 4.6/4.7 id patterns and/or ``supports_max_reasoning_effort``
+        # in the model map (same pattern as ``xhigh`` below).
+        if effort == "max" and not (
+            self._is_opus_4_6_model(model)
+            or self._is_opus_4_7_model(model)
+            or self._supports_effort_level(model, "max")
+        ):
             raise ValueError(
-                f"effort='max' is only supported by Claude Opus 4.6. "
-                f"Got model: {model}"
+                f"effort='max' is not supported by this model. Got model: {model}"
             )
         # ``xhigh`` is data-driven via ``supports_xhigh_reasoning_effort`` so
         # enabling it for a new model is a pure model-map change.

litellm/model_prices_and_context_window_backup.json

@@ -9163,6 +9163,7 @@
         "supports_tool_choice": true,
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
+        "supports_max_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
         "provider_specific_entry": {
             "us": 1.1,
@@ -9195,6 +9196,7 @@
         "supports_tool_choice": true,
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
+        "supports_max_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
         "provider_specific_entry": {
             "us": 1.1,

model_prices_and_context_window.json

@@ -9177,6 +9177,7 @@
         "supports_tool_choice": true,
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
+        "supports_max_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
         "provider_specific_entry": {
             "us": 1.1,
@@ -9209,6 +9210,7 @@
         "supports_tool_choice": true,
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
+        "supports_max_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
         "provider_specific_entry": {
             "us": 1.1,

tests/test_litellm/llms/anthropic/chat/test_anthropic_chat_transformation.py

@@ -1654,7 +1654,7 @@ def test_max_effort_rejected_for_opus_45():
     messages = [{"role": "user", "content": "Test"}]
 
     with pytest.raises(
-        ValueError, match="effort='max' is only supported by Claude Opus 4.6"
+        ValueError, match="effort='max' is not supported by this model"
     ):
         optional_params = {"output_config": {"effort": "max"}}
         config.transform_request(
@@ -2213,12 +2213,12 @@ def test_reasoning_effort_does_not_set_output_config_for_older_models():
 
 
 def test_max_effort_rejected_for_sonnet_46():
-    """Test that effort='max' is rejected for Sonnet 4.6 (only Opus 4.6 supports max)."""
+    """Test that effort='max' is rejected for Sonnet 4.6 (Opus-only effort level)."""
     config = AnthropicConfig()
     messages = [{"role": "user", "content": "Test"}]
 
     with pytest.raises(
-        ValueError, match="effort='max' is only supported by Claude Opus 4.6"
+        ValueError, match="effort='max' is not supported by this model"
     ):
         config.transform_request(
             model="claude-sonnet-4-6-20260219",
@@ -2245,6 +2245,22 @@ def test_max_effort_accepted_for_opus_46():
     assert result["output_config"]["effort"] == "max"
 
 
+def test_max_effort_accepted_for_opus_47():
+    """Test that effort='max' works for Opus 4.7."""
+    config = AnthropicConfig()
+    messages = [{"role": "user", "content": "Test"}]
+
+    result = config.transform_request(
+        model="claude-opus-4-7",
+        messages=messages,
+        optional_params={"output_config": {"effort": "max"}},
+        litellm_params={},
+        headers={},
+    )
+
+    assert result["output_config"]["effort"] == "max"
+
+
 def test_effort_beta_header_not_injected_for_46_models():
     """
     Test that is_effort_used returns False for Claude 4.6 models.