[responsesAPI][3] ResponsesParser to set up non harmony MCP (#29413)

Signed-off-by: Andrew Xia <axia@fb.com>
Co-authored-by: Andrew Xia <axia@fb.com>

tests/entrypoints/openai/test_response_api_parsable_context.py

@@ -0,0 +1,87 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+
+import pytest
+import pytest_asyncio
+from openai import OpenAI
+
+from ...utils import RemoteOpenAIServer
+
+MODEL_NAME = "Qwen/Qwen3-8B"
+
+
+@pytest.fixture(scope="module")
+def server():
+    args = ["--reasoning-parser", "qwen3", "--max_model_len", "5000"]
+    env_dict = dict(
+        VLLM_ENABLE_RESPONSES_API_STORE="1",
+        VLLM_USE_EXPERIMENTAL_PARSER_CONTEXT="1",
+        # uncomment for tool calling
+        # PYTHON_EXECUTION_BACKEND="dangerously_use_uv",
+    )
+
+    with RemoteOpenAIServer(MODEL_NAME, args, env_dict=env_dict) as remote_server:
+        yield remote_server
+
+
+@pytest_asyncio.fixture
+async def client(server):
+    async with server.get_async_client() as async_client:
+        yield async_client
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("model_name", [MODEL_NAME])
+async def test_basic(client: OpenAI, model_name: str):
+    response = await client.responses.create(
+        model=model_name,
+        input="What is 13 * 24?",
+    )
+    assert response is not None
+    print("response: ", response)
+    assert response.status == "completed"
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("model_name", [MODEL_NAME])
+async def test_reasoning_and_function_items(client: OpenAI, model_name: str):
+    response = await client.responses.create(
+        model=model_name,
+        input=[
+            {"type": "message", "content": "Hello.", "role": "user"},
+            {
+                "type": "reasoning",
+                "id": "lol",
+                "content": [
+                    {
+                        "type": "reasoning_text",
+                        "text": "We need to respond: greeting.",
+                    }
+                ],
+                "summary": [],
+            },
+            {
+                "arguments": '{"location": "Paris", "unit": "celsius"}',
+                "call_id": "call_5f7b38f3b81e4b8380fd0ba74f3ca3ab",
+                "name": "get_weather",
+                "type": "function_call",
+                "id": "fc_4fe5d6fc5b6c4d6fa5f24cc80aa27f78",
+                "status": "completed",
+            },
+            {
+                "call_id": "call_5f7b38f3b81e4b8380fd0ba74f3ca3ab",
+                "id": "fc_4fe5d6fc5b6c4d6fa5f24cc80aa27f78",
+                "output": "The weather in Paris is 20 Celsius",
+                "status": "completed",
+                "type": "function_call_output",
+            },
+        ],
+        temperature=0.0,
+    )
+    assert response is not None
+    assert response.status == "completed"
+    # make sure we get a reasoning and text output
+    assert response.output[0].type == "reasoning"
+    assert response.output[1].type == "message"
+    assert type(response.output[1].content[0].text) is str