diff --git a/llama_stack/providers/inline/batches/reference/batches.py b/llama_stack/providers/inline/batches/reference/batches.py
index 984ef5a90..1ff554e70 100644
--- a/llama_stack/providers/inline/batches/reference/batches.py
+++ b/llama_stack/providers/inline/batches/reference/batches.py
@@ -18,7 +18,15 @@ from pydantic import BaseModel
 from llama_stack.apis.batches import Batches, BatchObject, ListBatchesResponse
 from llama_stack.apis.common.errors import ConflictError, ResourceNotFoundError
 from llama_stack.apis.files import Files, OpenAIFilePurpose
-from llama_stack.apis.inference import Inference
+from llama_stack.apis.inference import (
+    Inference,
+    OpenAIAssistantMessageParam,
+    OpenAIDeveloperMessageParam,
+    OpenAIMessageParam,
+    OpenAISystemMessageParam,
+    OpenAIToolMessageParam,
+    OpenAIUserMessageParam,
+)
 from llama_stack.apis.models import Models
 from llama_stack.log import get_logger
 from llama_stack.providers.utils.kvstore import KVStore
@@ -65,6 +73,24 @@ class BatchRequest(BaseModel):
     body: dict[str, Any]
 
 
+def convert_to_openai_message_param(msg: dict[str, Any]) -> OpenAIMessageParam:
+    """Convert a message dictionary to OpenAIMessageParam based on role."""
+    role = msg.get("role")
+
+    if role == "user":
+        return OpenAIUserMessageParam(**msg)
+    elif role == "system":
+        return OpenAISystemMessageParam(**msg)
+    elif role == "assistant":
+        return OpenAIAssistantMessageParam(**msg)
+    elif role == "tool":
+        return OpenAIToolMessageParam(**msg)
+    elif role == "developer":
+        return OpenAIDeveloperMessageParam(**msg)
+    else:
+        raise ValueError(f"Unknown message role: {role}")
+
+
 class ReferenceBatchesImpl(Batches):
     """Reference implementation of the Batches API.
 
@@ -517,6 +543,7 @@ class ReferenceBatchesImpl(Batches):
 
         try:
             # TODO(SECURITY): review body for security issues
+            request.body["messages"] = [convert_to_openai_message_param(msg) for msg in request.body["messages"]]
             chat_response = await self.inference_api.openai_chat_completion(**request.body)
 
             # this is for mypy, we don't allow streaming so we'll get the right type