diff --git a/endpoints/OAI/types/chat_completion.py b/endpoints/OAI/types/chat_completion.py
index 15988cc..0bd91e0 100644
--- a/endpoints/OAI/types/chat_completion.py
+++ b/endpoints/OAI/types/chat_completion.py
@@ -11,7 +11,7 @@ from endpoints.OAI.types.tools import ToolSpec, ToolCall, tool_call_schema
 class ChatCompletionLogprob(BaseModel):
     token: str
     logprob: float
-    top_logprobs: Optional[List["ChatCompletionLogprob"]] = None
+    top_logprobs: Optional[List["ChatCompletionLogprob"]] = Field(default_factory=list)
 
 
 class ChatCompletionLogprobs(BaseModel):
@@ -30,8 +30,10 @@ class ChatCompletionMessagePart(BaseModel):
 
 class ChatCompletionMessage(BaseModel):
     role: str = "user"
-    content: Optional[Union[str, List[ChatCompletionMessagePart]]] = None
-    tool_calls: Optional[List[ToolCall]] = None
+    content: Optional[Union[str, List[ChatCompletionMessagePart]]] = Field(
+        default_factory=list
+    )
+    tool_calls: Optional[List[ToolCall]] = Field(default_factory=list)
     tool_calls_json: SkipJsonSchema[Optional[str]] = None
 
 
@@ -76,13 +78,15 @@ class ChatCompletionRequest(CommonCompletionRequest):
     # tools is follows the format OAI schema, functions is more flexible
     # both are available in the chat template.
 
-    tools: Optional[List[ToolSpec]] = None
-    functions: Optional[List[Dict]] = None
+    tools: Optional[List[ToolSpec]] = Field(default_factory=list)
+    functions: Optional[List[Dict]] = Field(default_factory=list)
 
     # Typically collected from Chat Template.
     # Don't include this in the OpenAPI docs
     # TODO: Use these custom parameters
-    tool_call_start: SkipJsonSchema[Optional[List[Union[str, int]]]] = None
+    tool_call_start: SkipJsonSchema[Optional[List[Union[str, int]]]] = Field(
+        default_factory=list
+    )
     tool_call_end: SkipJsonSchema[Optional[str]] = None
     tool_call_schema: SkipJsonSchema[Optional[dict]] = tool_call_schema
 
diff --git a/endpoints/OAI/utils/chat_completion.py b/endpoints/OAI/utils/chat_completion.py
index 11d4088..5975173 100644
--- a/endpoints/OAI/utils/chat_completion.py
+++ b/endpoints/OAI/utils/chat_completion.py
@@ -210,14 +210,14 @@ async def _append_template_metadata(data: ChatCompletionRequest, template_vars:
 async def format_messages_with_template(
     messages: List[ChatCompletionMessage],
     existing_template_vars: Optional[dict] = None,
-    add_bos_token: bool = True,
-    ban_eos_token: bool = False,
 ):
     """Barebones function to format chat completion messages into a prompt."""
 
     template_vars = unwrap(existing_template_vars, {})
     mm_embeddings = MultimodalEmbeddingWrapper() if model.container.use_vision else None
 
+    # Convert all messages to a dictionary representation
+    message_dicts: List[dict] = []
     for message in messages:
         if isinstance(message.content, list):
             concatenated_content = ""
@@ -238,9 +238,12 @@ async def format_messages_with_template(
             # store the list of dicts rather than the ToolCallProcessor object.
             message.tool_calls = ToolCallProcessor.dump(message.tool_calls)
 
+        message_dicts.append(message.model_dump())
+
+    # Get all special tokens
     special_tokens_dict = model.container.get_special_tokens()
 
-    template_vars.update({"messages": messages, **special_tokens_dict})
+    template_vars.update({"messages": message_dicts, **special_tokens_dict})
 
     prompt = await model.container.prompt_template.render(template_vars)
     return prompt, mm_embeddings, template_vars
@@ -270,7 +273,7 @@ async def apply_chat_template(
         )
 
         prompt, mm_embeddings, template_vars = await format_messages_with_template(
-            data.messages, data.template_vars, data.add_bos_token, data.ban_eos_token
+            data.messages, data.template_vars
         )
 
         # Append response prefix if present