Merge pull request #39763 from BerriAI/litellm_fireworks_tool_choice_short_name

fix(fireworks_ai): resolve tool_choice and reasoning support for short model names

litellm/llms/fireworks_ai/chat/transformation.py

@@ -272,11 +272,15 @@ class FireworksAIConfig(FireworksAIMixin, OpenAIGPTConfig):
             )
 
         # Only add tool_choice for models that explicitly support it
-        if supports_tool_choice(model=model, custom_llm_provider="fireworks_ai"):
+        if self._get_model_cost_capability_exact(
+            model=model, capability="supports_tool_choice"
+        ) or supports_tool_choice(model=model, custom_llm_provider="fireworks_ai"):
             supported_params.append("tool_choice")
 
         # Only add reasoning params for models that support it
-        if supports_reasoning(model=model, custom_llm_provider="fireworks_ai"):
+        if self._get_model_cost_capability_exact(model=model, capability="supports_reasoning") or supports_reasoning(
+            model=model, custom_llm_provider="fireworks_ai"
+        ):
             supported_params.append("reasoning_effort")
             supported_params.append("reasoning_history")
             supported_params.append("thinking")

tests/test_litellm/llms/fireworks_ai/chat/test_fireworks_ai_chat_transformation.py

@@ -4,11 +4,9 @@ from unittest.mock import MagicMock, patch
 import pytest
 
 import litellm
-
-
 from litellm import get_model_info, supports_reasoning, supports_vision
-from litellm.llms.fireworks_ai.chat.transformation import FireworksAIConfig
 from litellm.constants import SESSION_ID_GENERATED_METADATA_KEY
+from litellm.llms.fireworks_ai.chat.transformation import FireworksAIConfig
 from litellm.llms.fireworks_ai.common_utils import get_fireworks_session_id
 from litellm.types.utils import (
     ChatCompletionMessageToolCall,
@@ -363,6 +361,27 @@ def test_get_supported_openai_params_parallel_tool_calls():
     assert "parallel_tool_calls" not in unsupported_params
 
 
+def test_get_supported_openai_params_short_model_name_resolves_account_prefixed_entry():
+    config = FireworksAIConfig()
+
+    supported_params = config.get_supported_openai_params(
+        "fireworks_ai/deepseek-v4-pro-0813"
+    )
+
+    assert "tool_choice" in supported_params
+    assert "reasoning_effort" in supported_params
+
+
+def test_get_supported_openai_params_preserves_generic_reasoning_fallback():
+    config = FireworksAIConfig()
+
+    supported_params = config.get_supported_openai_params(
+        "fireworks_ai/accounts/fireworks/models/glm-5p3-flash"
+    )
+
+    assert "reasoning_effort" in supported_params
+
+
 def test_get_supported_openai_params_parallel_tool_calls_without_tool_choice(
     monkeypatch,
 ):