list responses

# What does this PR do?


## Test Plan

tests/integration/agents/test_openai_responses.py

@@ -0,0 +1,97 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+from urllib.parse import urljoin
+
+import pytest
+import requests
+from openai import OpenAI
+
+from llama_stack.distribution.library_client import LlamaStackAsLibraryClient
+
+
+@pytest.fixture
+def openai_client(client_with_models):
+    base_url = f"{client_with_models.base_url}/v1/openai/v1"
+    return OpenAI(base_url=base_url, api_key="bar")
+
+
+@pytest.mark.parametrize(
+    "stream",
+    [
+        True,
+        False,
+    ],
+)
+@pytest.mark.parametrize(
+    "tools",
+    [
+        [],
+        [
+            {
+                "type": "function",
+                "name": "get_weather",
+                "description": "Get the weather in a given city",
+                "parameters": {
+                    "type": "object",
+                    "properties": {
+                        "city": {"type": "string", "description": "The city to get the weather for"},
+                    },
+                },
+            }
+        ],
+    ],
+)
+def test_responses_store(openai_client, client_with_models, text_model_id, stream, tools):
+    if isinstance(client_with_models, LlamaStackAsLibraryClient):
+        pytest.skip("OpenAI responses are not supported when testing with library client yet.")
+
+    client = openai_client
+    message = "What's the weather in Tokyo?" + (
+        " YOU MUST USE THE get_weather function to get the weather." if tools else ""
+    )
+    response = client.responses.create(
+        model=text_model_id,
+        input=[
+            {
+                "role": "user",
+                "content": message,
+            }
+        ],
+        stream=stream,
+        tools=tools,
+    )
+    if stream:
+        # accumulate the streamed content
+        content = ""
+        response_id = None
+        for chunk in response:
+            if response_id is None:
+                response_id = chunk.response.id
+            if not tools:
+                if chunk.type == "response.completed":
+                    response_id = chunk.response.id
+                    content = chunk.response.output[0].content[0].text
+    else:
+        response_id = response.id
+        if not tools:
+            content = response.output[0].content[0].text
+
+    # list responses is not available in the SDK
+    url = urljoin(str(client.base_url), "responses")
+    response = requests.get(url, headers={"Authorization": f"Bearer {client.api_key}"})
+    assert response.status_code == 200
+    data = response.json()["data"]
+    assert response_id in [r["id"] for r in data]
+
+    # test retrieve response
+    retrieved_response = client.responses.retrieve(response_id)
+    assert retrieved_response.id == response_id
+    assert retrieved_response.model == text_model_id
+    if tools:
+        assert retrieved_response.output[0].type == "function_call"
+    else:
+        assert retrieved_response.output[0].content[0].text == content