import json from urllib.parse import quote from mcp.types import TextContent, TextResourceContents from fastmcp.client.client import Client from fastmcp.server.server import FastMCP from fastmcp.tools.base import Tool from fastmcp.tools.function_tool import FunctionTool from tests.conftest import get_fn_name async def test_import_basic_functionality(): """Test that the import method properly imports tools and other resources.""" # Create main app and sub-app main_app = FastMCP("MainApp") sub_app = FastMCP("SubApp") # Add a tool to the sub-app @sub_app.tool def sub_tool() -> str: return "This is from the sub app" # Import the sub-app to the main app await main_app.import_server(sub_app, "sub") # Verify the tool was imported with the prefix main_tools = await main_app.list_tools() sub_tools = await sub_app.list_tools() assert any(t.name == "sub_sub_tool" for t in main_tools) assert any(t.name == "sub_tool" for t in sub_tools) # Verify the original tool still exists in the sub-app tool = await main_app.get_tool("sub_sub_tool") assert tool is not None # import_server creates copies with prefixed names (unlike mount which proxies) assert tool.name == "sub_sub_tool" assert isinstance(tool, FunctionTool) assert callable(tool.fn) async def test_import_multiple_apps(): """Test importing multiple apps to a main app.""" # Create main app and multiple sub-apps main_app = FastMCP("MainApp") weather_app = FastMCP("WeatherApp") news_app = FastMCP("NewsApp") # Add tools to each sub-app @weather_app.tool def get_forecast() -> str: return "Weather forecast" @news_app.tool def get_headlines() -> str: return "News headlines" # Import both sub-apps to the main app await main_app.import_server(weather_app, "weather") await main_app.import_server(news_app, "news") # Verify tools were imported with the correct prefixes tools = await main_app.list_tools() assert any(t.name == "weather_get_forecast" for t in tools) assert any(t.name == "news_get_headlines" for t in tools) async def test_import_combines_tools(): """Test that importing preserves existing tools with the same prefix.""" # Create apps main_app = FastMCP("MainApp") first_app = FastMCP("FirstApp") second_app = FastMCP("SecondApp") # Add tools to each sub-app @first_app.tool def first_tool() -> str: return "First app tool" @second_app.tool def second_tool() -> str: return "Second app tool" # Import first app await main_app.import_server(first_app, "api") tools = await main_app.list_tools() assert any(t.name == "api_first_tool" for t in tools) # Import second app to same prefix await main_app.import_server(second_app, "api") # Verify second tool is there tools = await main_app.list_tools() assert any(t.name == "api_second_tool" for t in tools) # Tools from both imports are combined assert any(t.name == "api_first_tool" for t in tools) async def test_import_with_resources(): """Test importing with resources.""" # Create apps main_app = FastMCP("MainApp") data_app = FastMCP("DataApp") # Add a resource to the data app @data_app.resource(uri="data://users") async def get_users() -> str: return "user1, user2" # Import the data app await main_app.import_server(data_app, "data") # Verify the resource was imported with the prefix resources = await main_app.list_resources() assert any(str(r.uri) == "data://data/users" for r in resources) async def test_import_with_resource_templates(): """Test importing with resource templates.""" # Create apps main_app = FastMCP("MainApp") user_app = FastMCP("UserApp") # Add a resource template to the user app @user_app.resource(uri="users://{user_id}/profile") def get_user_profile(user_id: str) -> str: import json return json.dumps( {"id": user_id, "name": f"User {user_id}"}, separators=(",", ":") ) # Import the user app await main_app.import_server(user_app, "api") # Verify the template was imported with the prefix templates = await main_app.list_resource_templates() assert any(t.uri_template == "users://api/{user_id}/profile" for t in templates) async def test_import_with_prompts(): """Test importing with prompts.""" # Create apps main_app = FastMCP("MainApp") assistant_app = FastMCP("AssistantApp") # Add a prompt to the assistant app @assistant_app.prompt def greeting(name: str) -> str: return f"Hello, {name}!" # Import the assistant app await main_app.import_server(assistant_app, "assistant") # Verify the prompt was imported with the prefix prompts = await main_app.list_prompts() assert any(p.name == "assistant_greeting" for p in prompts) async def test_import_multiple_resource_templates(): """Test importing multiple apps with resource templates.""" # Create apps main_app = FastMCP("MainApp") weather_app = FastMCP("WeatherApp") news_app = FastMCP("NewsApp") # Add templates to each app @weather_app.resource(uri="weather://{city}") def get_weather(city: str) -> str: return f"Weather for {city}" @news_app.resource(uri="news://{category}") def get_news(category: str) -> str: return f"News for {category}" # Import both apps await main_app.import_server(weather_app, "data") await main_app.import_server(news_app, "content") # Verify templates were imported with correct prefixes templates = await main_app.list_resource_templates() assert any(t.uri_template == "weather://data/{city}" for t in templates) assert any(t.uri_template == "news://content/{category}" for t in templates) async def test_import_multiple_prompts(): """Test importing multiple apps with prompts.""" # Create apps main_app = FastMCP("MainApp") python_app = FastMCP("PythonApp") sql_app = FastMCP("SQLApp") # Add prompts to each app @python_app.prompt def review_python(code: str) -> str: return f"Reviewing Python code:\n{code}" @sql_app.prompt def explain_sql(query: str) -> str: return f"Explaining SQL query:\n{query}" # Import both apps await main_app.import_server(python_app, "python") await main_app.import_server(sql_app, "sql") # Verify prompts were imported with correct prefixes prompts = await main_app.list_prompts() assert any(p.name == "python_review_python" for p in prompts) assert any(p.name == "sql_explain_sql" for p in prompts) async def test_tool_custom_name_preserved_when_imported(): """Test that a tool's custom name is preserved when imported.""" main_app = FastMCP("MainApp") api_app = FastMCP("APIApp") def fetch_data(query: str) -> str: return f"Data for query: {query}" api_app.add_tool(Tool.from_function(fetch_data, name="get_data")) await main_app.import_server(api_app, "api") # Check that the tool is accessible by its prefixed name tool = await main_app.get_tool("api_get_data") assert tool is not None # Check that the function name is preserved assert isinstance(tool, FunctionTool) assert get_fn_name(tool.fn) == "fetch_data" async def test_call_imported_custom_named_tool(): """Test calling an imported tool with a custom name.""" main_app = FastMCP("MainApp") api_app = FastMCP("APIApp") def fetch_data(query: str) -> str: return f"Data for query: {query}" api_app.add_tool(Tool.from_function(fetch_data, name="get_data")) await main_app.import_server(api_app, "api") async with Client(main_app) as client: result = await client.call_tool("api_get_data", {"query": "test"}) assert result.data == "Data for query: test" async def test_first_level_importing_with_custom_name(): """Test that a tool with a custom name is correctly imported at the first level.""" service_app = FastMCP("ServiceApp") provider_app = FastMCP("ProviderApp") def calculate_value(input: int) -> int: return input * 2 provider_app.add_tool(Tool.from_function(calculate_value, name="compute")) await service_app.import_server(provider_app, "provider") # Tool is accessible in the service app with the first prefix tool = await service_app.get_tool("provider_compute") assert tool is not None assert isinstance(tool, FunctionTool) assert get_fn_name(tool.fn) == "calculate_value" async def test_nested_importing_preserves_prefixes(): """Test that importing a previously imported app preserves prefixes.""" main_app = FastMCP("MainApp") service_app = FastMCP("ServiceApp") provider_app = FastMCP("ProviderApp") def calculate_value(input: int) -> int: return input * 2 provider_app.add_tool(Tool.from_function(calculate_value, name="compute")) await service_app.import_server(provider_app, "provider") await main_app.import_server(service_app, "service") # Tool is accessible in the main app with both prefixes tool = await main_app.get_tool("service_provider_compute") assert tool is not None async def test_call_nested_imported_tool(): """Test calling a tool through multiple levels of importing.""" main_app = FastMCP("MainApp") service_app = FastMCP("ServiceApp") provider_app = FastMCP("ProviderApp") def calculate_value(input: int) -> int: return input * 2 provider_app.add_tool(Tool.from_function(calculate_value, name="compute")) await service_app.import_server(provider_app, "provider") await main_app.import_server(service_app, "service") async with Client(main_app) as client: result = await client.call_tool("service_provider_compute", {"input": 21}) assert result.data == 42 async def test_import_with_proxy_tools(): """ Test importing with tools that have custom names (proxy tools). This tests that the tool's name doesn't change even though the registered name does, which is important because we need to forward that name to the proxy server correctly. """ # Create apps main_app = FastMCP("MainApp") api_app = FastMCP("APIApp") @api_app.tool def get_data(query: str) -> str: return f"Data for query: {query}" proxy_app = FastMCP.as_proxy(api_app) await main_app.import_server(proxy_app, "api") async with Client(main_app) as client: result = await client.call_tool("api_get_data", {"query": "test"}) assert result.data == "Data for query: test" async def test_import_with_proxy_prompts(): """ Test importing with prompts that have custom keys. This tests that the prompt's name doesn't change even though the registered key does, which is important for correct rendering. """ # Create apps main_app = FastMCP("MainApp") api_app = FastMCP("APIApp") @api_app.prompt def greeting(name: str) -> str: """Example greeting prompt.""" return f"Hello, {name} from API!" proxy_app = FastMCP.as_proxy(api_app) await main_app.import_server(proxy_app, "api") async with Client(main_app) as client: result = await client.get_prompt("api_greeting", {"name": "World"}) assert isinstance(result.messages[0].content, TextContent) assert result.messages[0].content.text == "Hello, World from API!" assert result.description == "Example greeting prompt." async def test_import_with_proxy_resources(): """ Test importing with resources that have custom keys. This tests that the resource's name doesn't change even though the registered key does, which is important for correct access. """ # Create apps main_app = FastMCP("MainApp") api_app = FastMCP("APIApp") # Create a resource in the API app @api_app.resource(uri="config://settings") def get_config() -> str: import json return json.dumps( { "api_key": "12345", "base_url": "https://api.example.com", } ) proxy_app = FastMCP.as_proxy(api_app) await main_app.import_server(proxy_app, "api") # Access the resource through the main app with the prefixed key async with Client(main_app) as client: result = await client.read_resource("config://api/settings") assert isinstance(result[0], TextResourceContents) content = json.loads(result[0].text) assert content["api_key"] == "12345" assert content["base_url"] == "https://api.example.com" async def test_import_with_proxy_resource_templates(): """ Test importing with resource templates that have custom keys. This tests that the template's name doesn't change even though the registered key does, which is important for correct instantiation. """ # Create apps main_app = FastMCP("MainApp") api_app = FastMCP("APIApp") # Create a resource template in the API app @api_app.resource(uri="user://{name}/{email}") def create_user(name: str, email: str) -> str: import json return json.dumps({"name": name, "email": email}) proxy_app = FastMCP.as_proxy(api_app) await main_app.import_server(proxy_app, "api") # Instantiate the template through the main app with the prefixed key quoted_name = quote("John Doe", safe="") quoted_email = quote("john@example.com", safe="") async with Client(main_app) as client: result = await client.read_resource(f"user://api/{quoted_name}/{quoted_email}") assert isinstance(result[0], TextResourceContents) content = json.loads(result[0].text) assert content["name"] == "John Doe" assert content["email"] == "john@example.com" async def test_import_with_no_prefix(): """Test importing a server without providing a prefix.""" main_app = FastMCP("MainApp") sub_app = FastMCP("SubApp") @sub_app.tool def sub_tool() -> str: return "Sub tool result" @sub_app.resource(uri="data://config") def sub_resource(): return "Sub resource data" @sub_app.resource(uri="users://{user_id}/info") def sub_template(user_id: str): return f"Sub template for user {user_id}" @sub_app.prompt def sub_prompt() -> str: return "Sub prompt content" # Import without prefix await main_app.import_server(sub_app) # Verify all component types are accessible with original names tools = await main_app.list_tools() resources = await main_app.list_resources() templates = await main_app.list_resource_templates() prompts = await main_app.list_prompts() assert any(t.name == "sub_tool" for t in tools) assert any(str(r.uri) == "data://config" for r in resources) assert any(t.uri_template == "users://{user_id}/info" for t in templates) assert any(p.name == "sub_prompt" for p in prompts) # Test actual functionality through Client async with Client(main_app) as client: # Test tool tool_result = await client.call_tool("sub_tool", {}) assert tool_result.data == "Sub tool result" # Test resource resource_result = await client.read_resource("data://config") assert isinstance(resource_result[0], TextResourceContents) assert resource_result[0].text == "Sub resource data" # Test template template_result = await client.read_resource("users://123/info") assert isinstance(template_result[0], TextResourceContents) assert template_result[0].text == "Sub template for user 123" # Test prompt prompt_result = await client.get_prompt("sub_prompt", {}) assert prompt_result.messages is not None assert isinstance(prompt_result.messages[0].content, TextContent) assert prompt_result.messages[0].content.text == "Sub prompt content" async def test_import_conflict_resolution_tools(): """Test that later imported tools overwrite earlier ones when names conflict.""" main_app = FastMCP("MainApp") first_app = FastMCP("FirstApp") second_app = FastMCP("SecondApp") @first_app.tool(name="shared_tool") def first_shared_tool() -> str: return "First app tool" @second_app.tool(name="shared_tool") def second_shared_tool() -> str: return "Second app tool" # Import both apps without prefix await main_app.import_server(first_app) await main_app.import_server(second_app) async with Client(main_app) as client: # The later imported server should win tools = await client.list_tools() tool_names = [t.name for t in tools] assert "shared_tool" in tool_names assert tool_names.count("shared_tool") == 1 # Should only appear once result = await client.call_tool("shared_tool", {}) assert result.data == "Second app tool" async def test_import_conflict_resolution_resources(): """Test that later imported resources overwrite earlier ones when URIs conflict.""" main_app = FastMCP("MainApp") first_app = FastMCP("FirstApp") second_app = FastMCP("SecondApp") @first_app.resource(uri="shared://data") def first_resource(): return "First app data" @second_app.resource(uri="shared://data") def second_resource(): return "Second app data" # Import both apps without prefix await main_app.import_server(first_app) await main_app.import_server(second_app) async with Client(main_app) as client: # The later imported server should win resources = await client.list_resources() resource_uris = [str(r.uri) for r in resources] assert "shared://data" in resource_uris assert resource_uris.count("shared://data") == 1 # Should only appear once result = await client.read_resource("shared://data") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Second app data" async def test_import_conflict_resolution_templates(): """Test that later imported templates overwrite earlier ones when URI templates conflict.""" main_app = FastMCP("MainApp") first_app = FastMCP("FirstApp") second_app = FastMCP("SecondApp") @first_app.resource(uri="users://{user_id}/profile") def first_template(user_id: str): return f"First app user {user_id}" @second_app.resource(uri="users://{user_id}/profile") def second_template(user_id: str): return f"Second app user {user_id}" # Import both apps without prefix await main_app.import_server(first_app) await main_app.import_server(second_app) async with Client(main_app) as client: # The later imported server should win templates = await client.list_resource_templates() template_uris = [t.uriTemplate for t in templates] assert "users://{user_id}/profile" in template_uris assert ( template_uris.count("users://{user_id}/profile") == 1 ) # Should only appear once result = await client.read_resource("users://123/profile") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Second app user 123" async def test_import_conflict_resolution_prompts(): """Test that later imported prompts overwrite earlier ones when names conflict.""" main_app = FastMCP("MainApp") first_app = FastMCP("FirstApp") second_app = FastMCP("SecondApp") @first_app.prompt(name="shared_prompt") def first_shared_prompt() -> str: return "First app prompt" @second_app.prompt(name="shared_prompt") def second_shared_prompt() -> str: return "Second app prompt" # Import both apps without prefix await main_app.import_server(first_app) await main_app.import_server(second_app) async with Client(main_app) as client: # The later imported server should win prompts = await client.list_prompts() prompt_names = [p.name for p in prompts] assert "shared_prompt" in prompt_names assert prompt_names.count("shared_prompt") == 1 # Should only appear once result = await client.get_prompt("shared_prompt", {}) assert result.messages is not None assert isinstance(result.messages[0].content, TextContent) assert result.messages[0].content.text == "Second app prompt" async def test_import_conflict_resolution_with_prefix(): """Test that later imported components overwrite earlier ones when prefixed names conflict.""" main_app = FastMCP("MainApp") first_app = FastMCP("FirstApp") second_app = FastMCP("SecondApp") @first_app.tool(name="shared_tool") def first_shared_tool() -> str: return "First app tool" @second_app.tool(name="shared_tool") def second_shared_tool() -> str: return "Second app tool" # Import both apps with same prefix await main_app.import_server(first_app, "api") await main_app.import_server(second_app, "api") async with Client(main_app) as client: # The later imported server should win tools = await client.list_tools() tool_names = [t.name for t in tools] assert "api_shared_tool" in tool_names assert tool_names.count("api_shared_tool") == 1 # Should only appear once result = await client.call_tool("api_shared_tool", {}) assert result.data == "Second app tool" async def test_import_server_resource_uri_prefixing(): """Test that resource URIs are prefixed when using import_server (names are NOT prefixed).""" # Create a sub-server with a resource sub_server = FastMCP("SubServer") @sub_server.resource("resource://test_resource") def test_resource() -> str: return "Test content" # Create main server and import sub-server with prefix main_server = FastMCP("MainServer") await main_server.import_server(sub_server, prefix="imported") # Get resources and verify URI prefixing (name should NOT be prefixed) resources = await main_server.list_resources() resource = next( r for r in resources if str(r.uri) == "resource://imported/test_resource" ) assert resource.name == "test_resource" async def test_import_server_resource_template_uri_prefixing(): """Test that resource template URIs are prefixed when using import_server (names are NOT prefixed).""" # Create a sub-server with a resource template sub_server = FastMCP("SubServer") @sub_server.resource("resource://data/{item_id}") def data_template(item_id: str) -> str: return f"Data for {item_id}" # Create main server and import sub-server with prefix main_server = FastMCP("MainServer") await main_server.import_server(sub_server, prefix="imported") # Get resource templates and verify URI prefixing (name should NOT be prefixed) templates = await main_server.list_resource_templates() template = next( t for t in templates if t.uri_template == "resource://imported/data/{item_id}" ) assert template.name == "data_template" async def test_import_server_with_new_prefix_format(): """Test that import_server correctly uses the new prefix format.""" # Create a server with resources source_server = FastMCP(name="SourceServer") @source_server.resource("resource://test-resource") def get_resource(): return "Resource content" @source_server.resource("resource:///absolute/path") def get_absolute_resource(): return "Absolute resource content" @source_server.resource("resource://{param}/template") def get_template_resource(param: str): return f"Template resource with {param}" # Create target server and import the source server target_server = FastMCP(name="TargetServer") await target_server.import_server(source_server, "imported") # Check that the resources were imported with the correct prefixes resources = await target_server.list_resources() templates = await target_server.list_resource_templates() assert any(str(r.uri) == "resource://imported/test-resource" for r in resources) assert any(str(r.uri) == "resource://imported//absolute/path" for r in resources) assert any( t.uri_template == "resource://imported/{param}/template" for t in templates ) # Verify we can access the resources async with Client(target_server) as client: result = await client.read_resource("resource://imported/test-resource") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Resource content" result = await client.read_resource("resource://imported//absolute/path") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Absolute resource content" result = await client.read_resource("resource://imported/param-value/template") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Template resource with param-value"