fix(anthropic): allow max output effort via model metadata

Make Anthropic output_config max-effort validation fully model-map driven and add max support metadata for Opus 4.7 + Opus 4.6 alias coverage, with focused tests for supported/unsupported models.

Made-with: Cursor

litellm/llms/anthropic/chat/transformation.py

@@ -182,22 +182,6 @@ class AnthropicConfig(AnthropicModelInfo, BaseConfig):
             tool_call["caller"] = cast(Dict[str, Any], anthropic_tool_content["caller"])  # type: ignore[typeddict-item]
         return tool_call
 
-    @staticmethod
-    def _is_opus_4_6_model(model: str) -> bool:
-        """Check if the model is specifically Claude Opus 4.6."""
-        model_lower = model.lower()
-        return any(
-            v in model_lower for v in ("opus-4-6", "opus_4_6", "opus-4.6", "opus_4.6")
-        )
-
-    @staticmethod
-    def _is_opus_4_7_model(model: str) -> bool:
-        """Check if the model is specifically Claude Opus 4.7."""
-        model_lower = model.lower()
-        return any(
-            v in model_lower for v in ("opus-4-7", "opus_4_7", "opus-4.7", "opus_4.7")
-        )
-
     @staticmethod
     def _supports_effort_level(model: str, level: str) -> bool:
         """Check ``supports_{level}_reasoning_effort`` in the model map.
@@ -1534,12 +1518,11 @@ 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`` support is model-map driven via ``supports_max_reasoning_effort``.
+        supports_max = self._supports_effort_level(model, "max")
+        if effort == "max" and not supports_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

@@ -1146,7 +1146,8 @@
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
-        "supports_native_structured_output": true
+        "supports_native_structured_output": true,
+        "supports_max_reasoning_effort": true
     },
     "global.anthropic.claude-opus-4-7": {
         "cache_creation_input_token_cost": 6.25e-06,
@@ -1174,7 +1175,8 @@
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
-        "supports_native_structured_output": true
+        "supports_native_structured_output": true,
+        "supports_max_reasoning_effort": true
     },
     "us.anthropic.claude-opus-4-7": {
         "cache_creation_input_token_cost": 6.875e-06,
@@ -1202,7 +1204,8 @@
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
-        "supports_native_structured_output": true
+        "supports_native_structured_output": true,
+        "supports_max_reasoning_effort": true
     },
     "eu.anthropic.claude-opus-4-7": {
         "cache_creation_input_token_cost": 6.875e-06,
@@ -1230,7 +1233,8 @@
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
-        "supports_native_structured_output": true
+        "supports_native_structured_output": true,
+        "supports_max_reasoning_effort": true
     },
     "au.anthropic.claude-opus-4-7": {
         "cache_creation_input_token_cost": 6.875e-06,
@@ -1258,7 +1262,8 @@
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
-        "supports_native_structured_output": true
+        "supports_native_structured_output": true,
+        "supports_max_reasoning_effort": true
     },
     "anthropic.claude-sonnet-4-6": {
         "cache_creation_input_token_cost": 3.75e-06,
@@ -9079,6 +9084,9 @@
         "cache_read_input_token_cost": 5e-07,
         "input_cost_per_token": 5e-06,
         "litellm_provider": "anthropic",
+        "aliases": [
+            "claude-opus-4-6-20250514"
+        ],
         "max_input_tokens": 1000000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
@@ -9163,6 +9171,7 @@
         "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 +9204,7 @@
         "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

@@ -1146,7 +1146,8 @@
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
-        "supports_native_structured_output": true
+        "supports_native_structured_output": true,
+        "supports_max_reasoning_effort": true
     },
     "global.anthropic.claude-opus-4-7": {
         "cache_creation_input_token_cost": 6.25e-06,
@@ -1174,7 +1175,8 @@
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
-        "supports_native_structured_output": true
+        "supports_native_structured_output": true,
+        "supports_max_reasoning_effort": true
     },
     "us.anthropic.claude-opus-4-7": {
         "cache_creation_input_token_cost": 6.875e-06,
@@ -1202,7 +1204,8 @@
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
-        "supports_native_structured_output": true
+        "supports_native_structured_output": true,
+        "supports_max_reasoning_effort": true
     },
     "eu.anthropic.claude-opus-4-7": {
         "cache_creation_input_token_cost": 6.875e-06,
@@ -1230,7 +1233,8 @@
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
-        "supports_native_structured_output": true
+        "supports_native_structured_output": true,
+        "supports_max_reasoning_effort": true
     },
     "au.anthropic.claude-opus-4-7": {
         "cache_creation_input_token_cost": 6.875e-06,
@@ -1258,7 +1262,8 @@
         "supports_vision": true,
         "supports_xhigh_reasoning_effort": true,
         "tool_use_system_prompt_tokens": 346,
-        "supports_native_structured_output": true
+        "supports_native_structured_output": true,
+        "supports_max_reasoning_effort": true
     },
     "anthropic.claude-sonnet-4-6": {
         "cache_creation_input_token_cost": 3.75e-06,
@@ -9079,6 +9084,9 @@
         "cache_read_input_token_cost": 5e-07,
         "input_cost_per_token": 5e-06,
         "litellm_provider": "anthropic",
+        "aliases": [
+            "claude-opus-4-6-20250514"
+        ],
         "max_input_tokens": 1000000,
         "max_output_tokens": 128000,
         "max_tokens": 128000,
@@ -9163,6 +9171,7 @@
         "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 +9204,7 @@
         "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

@@ -1653,9 +1653,7 @@ 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"
-    ):
+    with pytest.raises(ValueError, match="effort='max' is not supported by this model"):
         optional_params = {"output_config": {"effort": "max"}}
         config.transform_request(
             model="claude-opus-4-5-20251101",
@@ -2213,13 +2211,11 @@ 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."""
     config = AnthropicConfig()
     messages = [{"role": "user", "content": "Test"}]
 
-    with pytest.raises(
-        ValueError, match="effort='max' is only supported by Claude Opus 4.6"
-    ):
+    with pytest.raises(ValueError, match="effort='max' is not supported by this model"):
         config.transform_request(
             model="claude-sonnet-4-6-20260219",
             messages=messages,
@@ -2245,6 +2241,22 @@ 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.