[Frontend] Responses API MCP tools for built in tools and to pass through headers (vllm-project#24628)

Signed-off-by: Alec Solder <alecs@fb.com>
Signed-off-by: Alec S <10566873+alecsolder@users.noreply.github.com>
Co-authored-by: Alec Solder <alecs@fb.com>
Co-authored-by: Ye (Charlotte) Qi <yeq@meta.com>

Author: 3 people

tests/entrypoints/openai/test_response_api_mcp_tools.py

@@ -0,0 +1,106 @@
+# 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 = "openai/gpt-oss-20b"
+
+
+@pytest.fixture(scope="module")
+def monkeypatch_module():
+    from _pytest.monkeypatch import MonkeyPatch
+    mpatch = MonkeyPatch()
+    yield mpatch
+    mpatch.undo()
+
+
+@pytest.fixture(scope="module")
+def mcp_disabled_server(monkeypatch_module: pytest.MonkeyPatch):
+    args = ["--enforce-eager", "--tool-server", "demo"]
+
+    with monkeypatch_module.context() as m:
+        m.setenv("VLLM_ENABLE_RESPONSES_API_STORE", "1")
+        m.setenv("PYTHON_EXECUTION_BACKEND", "dangerously_use_uv")
+        with RemoteOpenAIServer(MODEL_NAME, args) as remote_server:
+            yield remote_server
+
+
+@pytest.fixture(scope="function")
+def mcp_enabled_server(monkeypatch_module: pytest.MonkeyPatch):
+    args = ["--enforce-eager", "--tool-server", "demo"]
+
+    with monkeypatch_module.context() as m:
+        m.setenv("VLLM_ENABLE_RESPONSES_API_STORE", "1")
+        m.setenv("PYTHON_EXECUTION_BACKEND", "dangerously_use_uv")
+        m.setenv("GPT_OSS_SYSTEM_TOOL_MCP_LABELS",
+                 "code_interpreter,container")
+        with RemoteOpenAIServer(MODEL_NAME, args) as remote_server:
+            yield remote_server
+
+
+@pytest_asyncio.fixture
+async def mcp_disabled_client(mcp_disabled_server):
+    async with mcp_disabled_server.get_async_client() as async_client:
+        yield async_client
+
+
+@pytest_asyncio.fixture
+async def mcp_enabled_client(mcp_enabled_server):
+    async with mcp_enabled_server.get_async_client() as async_client:
+        yield async_client
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("model_name", [MODEL_NAME])
+@pytest.mark.skip(reason="Code interpreter tool is not available in CI yet.")
+async def test_mcp_tool_env_flag_enabled(mcp_enabled_client: OpenAI,
+                                         model_name: str):
+    response = await mcp_enabled_client.responses.create(
+        model=model_name,
+        # TODO: Ideally should be able to set max tool calls
+        # to prevent multi-turn, but it is not currently supported
+        # would speed up the test
+        input=("What's the first 4 digits after the decimal point of "
+               "cube root of `19910212 * 20250910`? "
+               "Show only the digits. The python interpreter is not stateful "
+               "and you must print to see the output."),
+        tools=[{
+            "type": "mcp",
+            "server_label": "code_interpreter",
+            # URL unused for DemoToolServer
+            "server_url": "http://localhost:8888"
+        }],
+    )
+    assert response is not None
+    assert response.status == "completed"
+    assert response.usage.output_tokens_details.tool_output_tokens > 0
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("model_name", [MODEL_NAME])
+@pytest.mark.skip(reason="Code interpreter tool is not available in CI yet.")
+async def test_mcp_tool_env_flag_disabled(mcp_disabled_client: OpenAI,
+                                          model_name: str):
+    response = await mcp_disabled_client.responses.create(
+        model=model_name,
+        # TODO: Ideally should be able to set max tool calls
+        # to prevent multi-turn, but it is not currently supported
+        # would speed up the test
+        input=("What's the first 4 digits after the decimal point of "
+               "cube root of `19910212 * 20250910`? "
+               "Show only the digits. The python interpreter is not stateful "
+               "and you must print to see the output."),
+        tools=[{
+            "type": "mcp",
+            "server_label": "code_interpreter",
+            # URL unused for DemoToolServer
+            "server_url": "http://localhost:8888"
+        }],
+    )
+    assert response is not None
+    assert response.status == "completed"
+    assert response.usage.output_tokens_details.tool_output_tokens == 0

tests/entrypoints/openai/test_response_api_with_harmony.py

@@ -454,7 +454,13 @@ async def test_web_search(client: OpenAI, model_name: str):
 async def test_code_interpreter(client: OpenAI, model_name: str):
     response = await client.responses.create(
         model=model_name,
-        input="Multiply 64548*15151 using builtin python interpreter.",
+        # TODO: Ideally should be able to set max tool calls
+        # to prevent multi-turn, but it is not currently supported
+        # would speed up the test
+        input=("What's the first 4 digits after the decimal point of "
+               "cube root of `19910212 * 20250910`? "
+               "Show only the digits. The python interpreter is not stateful "
+               "and you must print to see the output."),
         tools=[{
             "type": "code_interpreter",
             "container": {
@@ -464,6 +470,7 @@ async def test_code_interpreter(client: OpenAI, model_name: str):
     )
     assert response is not None
     assert response.status == "completed"
+    assert response.usage.output_tokens_details.tool_output_tokens > 0
 
 
 def get_weather(latitude, longitude):

tests/test_envs.py

@@ -0,0 +1,216 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+import os
+from unittest.mock import patch
+
+import pytest
+
+from vllm.envs import env_list_with_choices, env_with_choices
+
+
+class TestEnvWithChoices:
+    """Test cases for env_with_choices function."""
+
+    def test_default_value_returned_when_env_not_set(self):
+        """Test default is returned when env var is not set."""
+        env_func = env_with_choices("NONEXISTENT_ENV", "default",
+                                    ["option1", "option2"])
+        assert env_func() == "default"
+
+    def test_none_default_returned_when_env_not_set(self):
+        """Test that None is returned when env not set and default is None."""
+        env_func = env_with_choices("NONEXISTENT_ENV", None,
+                                    ["option1", "option2"])
+        assert env_func() is None
+
+    def test_valid_value_returned_case_sensitive(self):
+        """Test that valid value is returned in case sensitive mode."""
+        with patch.dict(os.environ, {"TEST_ENV": "option1"}):
+            env_func = env_with_choices("TEST_ENV",
+                                        "default", ["option1", "option2"],
+                                        case_sensitive=True)
+            assert env_func() == "option1"
+
+    def test_valid_lowercase_value_returned_case_insensitive(self):
+        """Test that lowercase value is accepted in case insensitive mode."""
+        with patch.dict(os.environ, {"TEST_ENV": "option1"}):
+            env_func = env_with_choices("TEST_ENV",
+                                        "default", ["OPTION1", "OPTION2"],
+                                        case_sensitive=False)
+            assert env_func() == "option1"
+
+    def test_valid_uppercase_value_returned_case_insensitive(self):
+        """Test that uppercase value is accepted in case insensitive mode."""
+        with patch.dict(os.environ, {"TEST_ENV": "OPTION1"}):
+            env_func = env_with_choices("TEST_ENV",
+                                        "default", ["option1", "option2"],
+                                        case_sensitive=False)
+            assert env_func() == "OPTION1"
+
+    def test_invalid_value_raises_error_case_sensitive(self):
+        """Test that invalid value raises ValueError in case sensitive mode."""
+        with patch.dict(os.environ, {"TEST_ENV": "invalid"}):
+            env_func = env_with_choices("TEST_ENV",
+                                        "default", ["option1", "option2"],
+                                        case_sensitive=True)
+            with pytest.raises(ValueError,
+                               match="Invalid value 'invalid' for TEST_ENV"):
+                env_func()
+
+    def test_case_mismatch_raises_error_case_sensitive(self):
+        """Test that case mismatch raises ValueError in case sensitive mode."""
+        with patch.dict(os.environ, {"TEST_ENV": "OPTION1"}):
+            env_func = env_with_choices("TEST_ENV",
+                                        "default", ["option1", "option2"],
+                                        case_sensitive=True)
+            with pytest.raises(ValueError,
+                               match="Invalid value 'OPTION1' for TEST_ENV"):
+                env_func()
+
+    def test_invalid_value_raises_error_case_insensitive(self):
+        """Test that invalid value raises ValueError when case insensitive."""
+        with patch.dict(os.environ, {"TEST_ENV": "invalid"}):
+            env_func = env_with_choices("TEST_ENV",
+                                        "default", ["option1", "option2"],
+                                        case_sensitive=False)
+            with pytest.raises(ValueError,
+                               match="Invalid value 'invalid' for TEST_ENV"):
+                env_func()
+
+    def test_callable_choices_resolved_correctly(self):
+        """Test that callable choices are resolved correctly."""
+
+        def get_choices():
+            return ["dynamic1", "dynamic2"]
+
+        with patch.dict(os.environ, {"TEST_ENV": "dynamic1"}):
+            env_func = env_with_choices("TEST_ENV", "default", get_choices)
+            assert env_func() == "dynamic1"
+
+    def test_callable_choices_with_invalid_value(self):
+        """Test that callable choices raise error for invalid values."""
+
+        def get_choices():
+            return ["dynamic1", "dynamic2"]
+
+        with patch.dict(os.environ, {"TEST_ENV": "invalid"}):
+            env_func = env_with_choices("TEST_ENV", "default", get_choices)
+            with pytest.raises(ValueError,
+                               match="Invalid value 'invalid' for TEST_ENV"):
+                env_func()
+
+
+class TestEnvListWithChoices:
+    """Test cases for env_list_with_choices function."""
+
+    def test_default_list_returned_when_env_not_set(self):
+        """Test that default list is returned when env var is not set."""
+        env_func = env_list_with_choices("NONEXISTENT_ENV",
+                                         ["default1", "default2"],
+                                         ["option1", "option2"])
+        assert env_func() == ["default1", "default2"]
+
+    def test_empty_default_list_returned_when_env_not_set(self):
+        """Test that empty default list is returned when env not set."""
+        env_func = env_list_with_choices("NONEXISTENT_ENV", [],
+                                         ["option1", "option2"])
+        assert env_func() == []
+
+    def test_single_valid_value_parsed_correctly(self):
+        """Test that single valid value is parsed correctly."""
+        with patch.dict(os.environ, {"TEST_ENV": "option1"}):
+            env_func = env_list_with_choices("TEST_ENV", [],
+                                             ["option1", "option2"])
+            assert env_func() == ["option1"]
+
+    def test_multiple_valid_values_parsed_correctly(self):
+        """Test that multiple valid values are parsed correctly."""
+        with patch.dict(os.environ, {"TEST_ENV": "option1,option2"}):
+            env_func = env_list_with_choices("TEST_ENV", [],
+                                             ["option1", "option2"])
+            assert env_func() == ["option1", "option2"]
+
+    def test_values_with_whitespace_trimmed(self):
+        """Test that values with whitespace are trimmed correctly."""
+        with patch.dict(os.environ, {"TEST_ENV": " option1 , option2 "}):
+            env_func = env_list_with_choices("TEST_ENV", [],
+                                             ["option1", "option2"])
+            assert env_func() == ["option1", "option2"]
+
+    def test_empty_values_filtered_out(self):
+        """Test that empty values are filtered out."""
+        with patch.dict(os.environ, {"TEST_ENV": "option1,,option2,"}):
+            env_func = env_list_with_choices("TEST_ENV", [],
+                                             ["option1", "option2"])
+            assert env_func() == ["option1", "option2"]
+
+    def test_empty_string_returns_default(self):
+        """Test that empty string returns default."""
+        with patch.dict(os.environ, {"TEST_ENV": ""}):
+            env_func = env_list_with_choices("TEST_ENV", ["default"],
+                                             ["option1", "option2"])
+            assert env_func() == ["default"]
+
+    def test_only_commas_returns_default(self):
+        """Test that string with only commas returns default."""
+        with patch.dict(os.environ, {"TEST_ENV": ",,,"}):
+            env_func = env_list_with_choices("TEST_ENV", ["default"],
+                                             ["option1", "option2"])
+            assert env_func() == ["default"]
+
+    def test_case_sensitive_validation(self):
+        """Test case sensitive validation."""
+        with patch.dict(os.environ, {"TEST_ENV": "option1,OPTION2"}):
+            env_func = env_list_with_choices("TEST_ENV", [],
+                                             ["option1", "option2"],
+                                             case_sensitive=True)
+            with pytest.raises(ValueError,
+                               match="Invalid value 'OPTION2' in TEST_ENV"):
+                env_func()
+
+    def test_case_insensitive_validation(self):
+        """Test case insensitive validation."""
+        with patch.dict(os.environ, {"TEST_ENV": "OPTION1,option2"}):
+            env_func = env_list_with_choices("TEST_ENV", [],
+                                             ["option1", "option2"],
+                                             case_sensitive=False)
+            assert env_func() == ["OPTION1", "option2"]
+
+    def test_invalid_value_in_list_raises_error(self):
+        """Test that invalid value in list raises ValueError."""
+        with patch.dict(os.environ, {"TEST_ENV": "option1,invalid,option2"}):
+            env_func = env_list_with_choices("TEST_ENV", [],
+                                             ["option1", "option2"])
+            with pytest.raises(ValueError,
+                               match="Invalid value 'invalid' in TEST_ENV"):
+                env_func()
+
+    def test_callable_choices_resolved_correctly(self):
+        """Test that callable choices are resolved correctly."""
+
+        def get_choices():
+            return ["dynamic1", "dynamic2"]
+
+        with patch.dict(os.environ, {"TEST_ENV": "dynamic1,dynamic2"}):
+            env_func = env_list_with_choices("TEST_ENV", [], get_choices)
+            assert env_func() == ["dynamic1", "dynamic2"]
+
+    def test_callable_choices_with_invalid_value(self):
+        """Test that callable choices raise error for invalid values."""
+
+        def get_choices():
+            return ["dynamic1", "dynamic2"]
+
+        with patch.dict(os.environ, {"TEST_ENV": "dynamic1,invalid"}):
+            env_func = env_list_with_choices("TEST_ENV", [], get_choices)
+            with pytest.raises(ValueError,
+                               match="Invalid value 'invalid' in TEST_ENV"):
+                env_func()
+
+    def test_duplicate_values_preserved(self):
+        """Test that duplicate values in the list are preserved."""
+        with patch.dict(os.environ, {"TEST_ENV": "option1,option1,option2"}):
+            env_func = env_list_with_choices("TEST_ENV", [],
+                                             ["option1", "option2"])
+            assert env_func() == ["option1", "option1", "option2"]