diff --git a/llama_stack/apis/agents/openai_responses.py b/llama_stack/apis/agents/openai_responses.py
index 8e11b2123..6a300e490 100644
--- a/llama_stack/apis/agents/openai_responses.py
+++ b/llama_stack/apis/agents/openai_responses.py
@@ -131,3 +131,20 @@ OpenAIResponseInputTool = Annotated[
     Field(discriminator="type"),
 ]
 register_schema(OpenAIResponseInputTool, name="OpenAIResponseInputTool")
+
+
+@json_schema_type
+class OpenAIResponseInputItemMessage(OpenAIResponseInputMessage):
+    id: str
+
+
+@json_schema_type
+class OpenAIResponseInputItemList(BaseModel):
+    data: list[OpenAIResponseInputItemMessage]
+    object: Literal["list"] = "list"
+
+
+@json_schema_type
+class OpenAIResponsePreviousResponseWithInputItems(BaseModel):
+    input_items: OpenAIResponseInputItemList
+    response: OpenAIResponseObject
diff --git a/llama_stack/providers/inline/agents/meta_reference/openai_responses.py b/llama_stack/providers/inline/agents/meta_reference/openai_responses.py
index 172dbd5ae..6be6513fb 100644
--- a/llama_stack/providers/inline/agents/meta_reference/openai_responses.py
+++ b/llama_stack/providers/inline/agents/meta_reference/openai_responses.py
@@ -12,7 +12,10 @@ from typing import cast
 from openai.types.chat import ChatCompletionToolParam
 
 from llama_stack.apis.agents.openai_responses import (
+    OpenAIResponseInputItemList,
+    OpenAIResponseInputItemMessage,
     OpenAIResponseInputMessage,
+    OpenAIResponseInputMessageContent,
     OpenAIResponseInputMessageContentImage,
     OpenAIResponseInputMessageContentText,
     OpenAIResponseInputTool,
@@ -24,6 +27,7 @@ from llama_stack.apis.agents.openai_responses import (
     OpenAIResponseOutputMessage,
     OpenAIResponseOutputMessageContentOutputText,
     OpenAIResponseOutputMessageWebSearchToolCall,
+    OpenAIResponsePreviousResponseWithInputItems,
 )
 from llama_stack.apis.inference.inference import (
     Inference,
@@ -52,9 +56,56 @@ logger = get_logger(name=__name__, category="openai_responses")
 OPENAI_RESPONSES_PREFIX = "openai_responses:"
 
 
-async def _previous_response_to_messages(previous_response: OpenAIResponseObject) -> list[OpenAIMessageParam]:
+async def _convert_response_input_content_to_chat_content_parts(
+    input_content: list[OpenAIResponseInputMessageContent],
+) -> list[OpenAIChatCompletionContentPartParam]:
+    """
+    Convert a list of input content items to a list of chat completion content parts
+    """
+    content_parts = []
+    for input_content_part in input_content:
+        if isinstance(input_content_part, OpenAIResponseInputMessageContentText):
+            content_parts.append(OpenAIChatCompletionContentPartTextParam(text=input_content_part.text))
+        elif isinstance(input_content_part, OpenAIResponseInputMessageContentImage):
+            if input_content_part.image_url:
+                image_url = OpenAIImageURL(url=input_content_part.image_url, detail=input_content_part.detail)
+                content_parts.append(OpenAIChatCompletionContentPartImageParam(image_url=image_url))
+    return content_parts
+
+
+async def _convert_response_input_to_chat_user_content(
+    input: str | list[OpenAIResponseInputMessage],
+) -> str | list[OpenAIChatCompletionContentPartParam]:
+    user_content: str | list[OpenAIChatCompletionContentPartParam] = ""
+    if isinstance(input, list):
+        user_content = []
+        for user_input in input:
+            if isinstance(user_input.content, list):
+                user_content.extend(await _convert_response_input_content_to_chat_content_parts(user_input.content))
+            else:
+                user_content.append(OpenAIChatCompletionContentPartTextParam(text=user_input.content))
+    else:
+        user_content = input
+    return user_content
+
+
+async def _previous_response_to_messages(
+    previous_response: OpenAIResponsePreviousResponseWithInputItems,
+) -> list[OpenAIMessageParam]:
     messages: list[OpenAIMessageParam] = []
-    for output_message in previous_response.output:
+    for previous_message in previous_response.input_items.data:
+        previous_content = await _convert_response_input_content_to_chat_content_parts(previous_message.content)
+        if previous_message.role == "user":
+            converted_message = OpenAIUserMessageParam(content=previous_content)
+        elif previous_message.role == "assistant":
+            converted_message = OpenAIAssistantMessageParam(content=previous_content)
+        else:
+            # TODO: handle other message roles? unclear if system/developer roles are
+            # used in previous responses
+            continue
+        messages.append(converted_message)
+
+    for output_message in previous_response.response.output:
         if isinstance(output_message, OpenAIResponseOutputMessage):
             messages.append(OpenAIAssistantMessageParam(content=output_message.content[0].text))
     return messages
@@ -102,15 +153,19 @@ class OpenAIResponsesImpl:
         self.tool_groups_api = tool_groups_api
         self.tool_runtime_api = tool_runtime_api
 
-    async def get_openai_response(
-        self,
-        id: str,
-    ) -> OpenAIResponseObject:
+    async def _get_previous_response_with_input(self, id: str) -> OpenAIResponsePreviousResponseWithInputItems:
         key = f"{OPENAI_RESPONSES_PREFIX}{id}"
         response_json = await self.persistence_store.get(key=key)
         if response_json is None:
             raise ValueError(f"OpenAI response with id '{id}' not found")
-        return OpenAIResponseObject.model_validate_json(response_json)
+        return OpenAIResponsePreviousResponseWithInputItems.model_validate_json(response_json)
+
+    async def get_openai_response(
+        self,
+        id: str,
+    ) -> OpenAIResponseObject:
+        response_with_input = await self._get_previous_response_with_input(id)
+        return response_with_input.response
 
     async def create_openai_response(
         self,
@@ -126,8 +181,8 @@ class OpenAIResponsesImpl:
 
         messages: list[OpenAIMessageParam] = []
         if previous_response_id:
-            previous_response = await self.get_openai_response(previous_response_id)
-            messages.extend(await _previous_response_to_messages(previous_response))
+            previous_response_with_input = await self._get_previous_response_with_input(previous_response_id)
+            messages.extend(await _previous_response_to_messages(previous_response_with_input))
 
         # TODO: refactor this user_content parsing out into a separate method
         content: str | list[OpenAIChatCompletionContentPartParam] = ""
@@ -216,10 +271,32 @@ class OpenAIResponsesImpl:
 
         if store:
             # Store in kvstore
+
+            if isinstance(input, str):
+                # synthesize a message from the input string
+                input_content = OpenAIResponseInputMessageContentText(text=input)
+                input_content_item = OpenAIResponseInputItemMessage(
+                    role="user",
+                    content=[input_content],
+                    id=f"msg_{uuid.uuid4()}",
+                )
+                input_items_data = [input_content_item]
+            else:
+                # we already have a list of messages
+                input_items_data = []
+                for input_item in input:
+                    input_items_data.append(
+                        OpenAIResponseInputItemMessage(id=f"msg_{uuid.uuid4()}", **input_item.model_dump())
+                    )
+            input_items = OpenAIResponseInputItemList(data=input_items_data)
+            prev_response = OpenAIResponsePreviousResponseWithInputItems(
+                input_items=input_items,
+                response=response,
+            )
             key = f"{OPENAI_RESPONSES_PREFIX}{response.id}"
             await self.persistence_store.set(
                 key=key,
-                value=response.model_dump_json(),
+                value=prev_response.model_dump_json(),
             )
 
         if stream: