import os import warnings from pathlib import Path from tempfile import TemporaryDirectory from textwrap import dedent from unittest.mock import patch import pytest from fastmcp import FastMCP from fastmcp.client import Client from fastmcp.client.transports import PythonStdioTransport from fastmcp.settings import Settings from fastmcp.utilities.tests import caplog_for_fastmcp # reset deprecation warnings for this module pytestmark = pytest.mark.filterwarnings("default::DeprecationWarning") class TestSettingsImport: """Test settings import.""" async def test_settings_from_environment_issue_1749(self): """Test that when auth is enabled, the server starts.""" script = dedent(""" import os os.environ["FASTMCP_SERVER_AUTH"] = "fastmcp.server.auth.providers.azure.AzureProvider" os.environ["FASTMCP_SERVER_AUTH_AZURE_TENANT_ID"] = "A_Valid_Value" os.environ["FASTMCP_SERVER_AUTH_AZURE_CLIENT_ID"] = "A_Valid_Value" os.environ["FASTMCP_SERVER_AUTH_AZURE_CLIENT_SECRET"] = "A_Valid_Value" os.environ["FASTMCP_SERVER_AUTH_AZURE_REDIRECT_PATH"] = "/auth/callback" os.environ["FASTMCP_SERVER_AUTH_AZURE_BASE_URL"] = "http://localhost:8000" os.environ["FASTMCP_SERVER_AUTH_AZURE_REQUIRED_SCOPES"] = "User.Read,email,profile" import fastmcp mcp = fastmcp.FastMCP("TestServer") mcp.run() """) with TemporaryDirectory() as temp_dir: server_file = Path(temp_dir) / "server.py" server_file.write_text(script) transport: PythonStdioTransport = PythonStdioTransport( script_path=server_file ) async with Client[PythonStdioTransport](transport=transport) as client: tools = await client.list_tools() assert tools == [] class TestDeprecatedServerInitKwargs: """Test deprecated server initialization keyword arguments.""" def test_log_level_deprecation_warning(self): """Test that log_level raises a deprecation warning.""" with pytest.warns( DeprecationWarning, match=r"Providing `log_level` when creating a server is deprecated\. Provide it when calling `run` or as a global setting instead\.", ): server = FastMCP("TestServer", log_level="DEBUG") # Verify the setting is still applied assert server._deprecated_settings.log_level == "DEBUG" def test_debug_deprecation_warning(self): """Test that debug raises a deprecation warning.""" with pytest.warns( DeprecationWarning, match=r"Providing `debug` when creating a server is deprecated\. Provide it when calling `run` or as a global setting instead\.", ): server = FastMCP("TestServer", debug=True) # Verify the setting is still applied assert server._deprecated_settings.debug is True def test_host_deprecation_warning(self): """Test that host raises a deprecation warning.""" with pytest.warns( DeprecationWarning, match=r"Providing `host` when creating a server is deprecated\. Provide it when calling `run` or as a global setting instead\.", ): server = FastMCP("TestServer", host="0.0.0.0") # Verify the setting is still applied assert server._deprecated_settings.host == "0.0.0.0" def test_port_deprecation_warning(self): """Test that port raises a deprecation warning.""" with pytest.warns( DeprecationWarning, match=r"Providing `port` when creating a server is deprecated\. Provide it when calling `run` or as a global setting instead\.", ): server = FastMCP("TestServer", port=8080) # Verify the setting is still applied assert server._deprecated_settings.port == 8080 def test_sse_path_deprecation_warning(self): """Test that sse_path raises a deprecation warning.""" with pytest.warns( DeprecationWarning, match=r"Providing `sse_path` when creating a server is deprecated\. Provide it when calling `run` or as a global setting instead\.", ): server = FastMCP("TestServer", sse_path="/custom-sse") # Verify the setting is still applied assert server._deprecated_settings.sse_path == "/custom-sse" def test_message_path_deprecation_warning(self): """Test that message_path raises a deprecation warning.""" with pytest.warns( DeprecationWarning, match=r"Providing `message_path` when creating a server is deprecated\. Provide it when calling `run` or as a global setting instead\.", ): server = FastMCP("TestServer", message_path="/custom-message") # Verify the setting is still applied assert server._deprecated_settings.message_path == "/custom-message" def test_streamable_http_path_deprecation_warning(self): """Test that streamable_http_path raises a deprecation warning.""" with pytest.warns( DeprecationWarning, match=r"Providing `streamable_http_path` when creating a server is deprecated\. Provide it when calling `run` or as a global setting instead\.", ): server = FastMCP("TestServer", streamable_http_path="/custom-http") # Verify the setting is still applied assert server._deprecated_settings.streamable_http_path == "/custom-http" def test_json_response_deprecation_warning(self): """Test that json_response raises a deprecation warning.""" with pytest.warns( DeprecationWarning, match=r"Providing `json_response` when creating a server is deprecated\. Provide it when calling `run` or as a global setting instead\.", ): server = FastMCP("TestServer", json_response=True) # Verify the setting is still applied assert server._deprecated_settings.json_response is True def test_stateless_http_deprecation_warning(self): """Test that stateless_http raises a deprecation warning.""" with pytest.warns( DeprecationWarning, match=r"Providing `stateless_http` when creating a server is deprecated\. Provide it when calling `run` or as a global setting instead\.", ): server = FastMCP("TestServer", stateless_http=True) # Verify the setting is still applied assert server._deprecated_settings.stateless_http is True def test_multiple_deprecated_kwargs_warnings(self): """Test that multiple deprecated kwargs each raise their own warning.""" with warnings.catch_warnings(record=True) as recorded_warnings: warnings.simplefilter("always") server = FastMCP( "TestServer", log_level="INFO", debug=False, host="127.0.0.1", port=9999, sse_path="/sse/", message_path="/msg", streamable_http_path="/http", json_response=False, stateless_http=False, ) # Should have 9 deprecation warnings (one for each deprecated parameter) deprecation_warnings = [ w for w in recorded_warnings if issubclass(w.category, DeprecationWarning) ] assert len(deprecation_warnings) == 9 # Verify all expected parameters are mentioned in warnings expected_params = { "log_level", "debug", "host", "port", "sse_path", "message_path", "streamable_http_path", "json_response", "stateless_http", } mentioned_params = set() for warning in deprecation_warnings: message = str(warning.message) for param in expected_params: if f"Providing `{param}`" in message: mentioned_params.add(param) assert mentioned_params == expected_params # Verify all settings are still applied assert server._deprecated_settings.log_level == "INFO" assert server._deprecated_settings.debug is False assert server._deprecated_settings.host == "127.0.0.1" assert server._deprecated_settings.port == 9999 assert server._deprecated_settings.sse_path == "/sse/" assert server._deprecated_settings.message_path == "/msg" assert server._deprecated_settings.streamable_http_path == "/http" assert server._deprecated_settings.json_response is False assert server._deprecated_settings.stateless_http is False def test_non_deprecated_kwargs_no_warnings(self): """Test that non-deprecated kwargs don't raise warnings.""" with warnings.catch_warnings(record=True) as recorded_warnings: warnings.simplefilter("always") server = FastMCP( name="TestServer", instructions="Test instructions", on_duplicate_tools="warn", on_duplicate_resources="error", on_duplicate_prompts="replace", resource_prefix_format="path", mask_error_details=True, ) # Should have no deprecation warnings deprecation_warnings = [ w for w in recorded_warnings if issubclass(w.category, DeprecationWarning) ] assert len(deprecation_warnings) == 0 # Verify server was created successfully assert server.name == "TestServer" assert server.instructions == "Test instructions" def test_none_values_no_warnings(self): """Test that None values for deprecated kwargs don't raise warnings.""" with warnings.catch_warnings(record=True) as recorded_warnings: warnings.simplefilter("always") FastMCP( "TestServer", log_level=None, debug=None, host=None, port=None, sse_path=None, message_path=None, streamable_http_path=None, json_response=None, stateless_http=None, ) # Should have no deprecation warnings for None values deprecation_warnings = [ w for w in recorded_warnings if issubclass(w.category, DeprecationWarning) ] assert len(deprecation_warnings) == 0 def test_deprecated_settings_inheritance_from_global(self): """Test that deprecated settings inherit from global settings when not provided.""" # Mock fastmcp.settings to test inheritance with patch("fastmcp.settings") as mock_settings: mock_settings.model_dump.return_value = { "log_level": "WARNING", "debug": True, "host": "0.0.0.0", "port": 3000, "sse_path": "/events", "message_path": "/messages", "streamable_http_path": "/stream", "json_response": True, "stateless_http": True, } mock_settings.server_auth = None # Add server_auth attribute server = FastMCP("TestServer") # Verify settings are inherited from global settings assert server._deprecated_settings.log_level == "WARNING" assert server._deprecated_settings.debug is True assert server._deprecated_settings.host == "0.0.0.0" assert server._deprecated_settings.port == 3000 assert server._deprecated_settings.sse_path == "/events" assert server._deprecated_settings.message_path == "/messages" assert server._deprecated_settings.streamable_http_path == "/stream" assert server._deprecated_settings.json_response is True assert server._deprecated_settings.stateless_http is True def test_deprecated_settings_override_global(self): """Test that deprecated settings override global settings when provided.""" # Mock fastmcp.settings to test override behavior with patch("fastmcp.settings") as mock_settings: mock_settings.model_dump.return_value = { "log_level": "WARNING", "debug": True, "host": "0.0.0.0", "port": 3000, "sse_path": "/events", "message_path": "/messages", "streamable_http_path": "/stream", "json_response": True, "stateless_http": True, } mock_settings.server_auth = None # Add server_auth attribute with warnings.catch_warnings(): warnings.simplefilter("ignore") # Ignore warnings for this test server = FastMCP( "TestServer", log_level="ERROR", debug=False, host="127.0.0.1", port=8080, ) # Verify provided settings override global settings assert server._deprecated_settings.log_level == "ERROR" assert server._deprecated_settings.debug is False assert server._deprecated_settings.host == "127.0.0.1" assert server._deprecated_settings.port == 8080 # Non-overridden settings should still come from global assert server._deprecated_settings.sse_path == "/events" assert server._deprecated_settings.message_path == "/messages" assert server._deprecated_settings.streamable_http_path == "/stream" assert server._deprecated_settings.json_response is True assert server._deprecated_settings.stateless_http is True def test_stacklevel_points_to_constructor_call(self): """Test that deprecation warnings point to the FastMCP constructor call.""" with warnings.catch_warnings(record=True) as recorded_warnings: warnings.simplefilter("always") FastMCP("TestServer", log_level="DEBUG") # Should have exactly one deprecation warning deprecation_warnings = [ w for w in recorded_warnings if issubclass(w.category, DeprecationWarning) ] assert len(deprecation_warnings) == 1 # The warning should point to the server.py file where FastMCP.__init__ is called # This verifies the stacklevel is working as intended (pointing to constructor) warning = deprecation_warnings[0] assert "server.py" in warning.filename class TestDeprecatedEnvironmentVariables: """Test deprecated environment variable prefixes.""" def test_fastmcp_server_env_var_deprecation_warning(self, caplog): """Test that FASTMCP_SERVER_ environment variables emit deprecation warnings.""" env_var_name = "FASTMCP_SERVER_HOST" original_value = os.environ.get(env_var_name) try: os.environ[env_var_name] = "192.168.1.1" with caplog_for_fastmcp(caplog): settings = Settings() # Check that a warning was logged assert any( "Using `FASTMCP_SERVER_` environment variables is deprecated. Use `FASTMCP_` instead." in record.message for record in caplog.records if record.levelname == "WARNING" ) # Verify the setting is still applied assert settings.host == "192.168.1.1" finally: # Clean up environment variable if original_value is not None: os.environ[env_var_name] = original_value else: os.environ.pop(env_var_name, None) class TestDeprecatedSettingsProperty: """Test deprecated settings property access.""" def test_settings_property_deprecation_warning(self, caplog): """Test that accessing fastmcp.settings.settings logs a deprecation warning.""" from fastmcp import settings with caplog_for_fastmcp(caplog): # Access the deprecated property deprecated_settings = settings.settings # Check that a warning was logged assert any( "Using fastmcp.settings.settings is deprecated. Use fastmcp.settings instead." in record.message for record in caplog.records if record.levelname == "WARNING" ) # Verify it still returns the same settings object assert deprecated_settings is settings assert isinstance(deprecated_settings, Settings)