diff --git a/letta/llm_api/openai_client.py b/letta/llm_api/openai_client.py
index e615315b..0f36c77e 100644
--- a/letta/llm_api/openai_client.py
+++ b/letta/llm_api/openai_client.py
@@ -453,7 +453,7 @@ class OpenAIClient(LLMClientBase):
             request_obj=data,
         )
 
-        request_data = data.model_dump(exclude_unset=True)
+        request_data = data.model_dump(exclude_unset=True, exclude_none=True)
         return request_data
 
     @trace_method
@@ -639,15 +639,8 @@ class OpenAIClient(LLMClientBase):
                 if not supports_structured_output(llm_config):
                     # Provider doesn't support structured output - ensure strict is False
                     tool.function.strict = False
-        request_data = data.model_dump(exclude_unset=True)
+        request_data = data.model_dump(exclude_unset=True, exclude_none=True)
 
-        # Fireworks uses strict validation (additionalProperties: false) and rejects
-        # reasoning fields that are not in their schema.
-        is_fireworks = llm_config.model_endpoint and "fireworks.ai" in llm_config.model_endpoint
-        if is_fireworks and "messages" in request_data:
-            for message in request_data["messages"]:
-                for field in ("reasoning_content_signature", "redacted_reasoning_content", "omitted_reasoning_content"):
-                    message.pop(field, None)
 
         # If Ollama
         # if llm_config.handle.startswith("ollama/") and llm_config.enable_reasoner: