import re import httpx import pytest from dirty_equals import IsStr from fastapi import FastAPI, HTTPException from httpx import ASGITransport, AsyncClient from pydantic import BaseModel, TypeAdapter from pydantic.networks import AnyUrl from fastmcp import FastMCP from fastmcp.server.openapi import FastMCPOpenAPI class User(BaseModel): id: int name: str active: bool class UserCreate(BaseModel): name: str active: bool @pytest.fixture def users_db() -> dict[int, User]: return { 1: User(id=1, name="Alice", active=True), 2: User(id=2, name="Bob", active=True), 3: User(id=3, name="Charlie", active=False), } @pytest.fixture def fastapi_app(users_db: dict[int, User]) -> FastAPI: app = FastAPI(title="FastAPI App") @app.get("/users", tags=["users", "list"]) async def get_users() -> list[User]: """Get all users.""" return sorted(users_db.values(), key=lambda x: x.id) @app.get("/users/{user_id}", tags=["users", "detail"]) async def get_user(user_id: int) -> User | None: """Get a user by ID.""" return users_db.get(user_id) @app.post("/users", tags=["users", "create"]) async def create_user(user: UserCreate) -> User: """Create a new user.""" user_id = max(users_db.keys()) + 1 new_user = User(id=user_id, **user.model_dump()) users_db[user_id] = new_user return new_user @app.patch("/users/{user_id}/name", tags=["users", "update"]) async def update_user_name(user_id: int, name: str) -> User: """Update a user's name.""" user = users_db.get(user_id) if user is None: raise HTTPException(status_code=404, detail="User not found") user.name = name return user return app @pytest.fixture def api_client(fastapi_app: FastAPI) -> AsyncClient: """Create a pre-configured httpx client for testing.""" return AsyncClient(transport=ASGITransport(app=fastapi_app), base_url="http://test") @pytest.fixture async def fastmcp_server( fastapi_app: FastAPI, api_client: httpx.AsyncClient ) -> FastMCPOpenAPI: openapi_spec = fastapi_app.openapi() return FastMCPOpenAPI( openapi_spec=openapi_spec, client=api_client, name="Test App", ) async def test_create_openapi_server( fastapi_app: FastAPI, api_client: httpx.AsyncClient ): openapi_spec = fastapi_app.openapi() server = FastMCPOpenAPI( openapi_spec=openapi_spec, client=api_client, name="Test App" ) assert isinstance(server, FastMCP) assert server.name == "Test App" async def test_create_openapi_server_classmethod( fastapi_app: FastAPI, api_client: httpx.AsyncClient ): server = FastMCP.from_openapi(openapi_spec=fastapi_app.openapi(), client=api_client) assert isinstance(server, FastMCPOpenAPI) assert server.name == "OpenAPI FastMCP" async def test_create_fastapi_server_classmethod(fastapi_app: FastAPI): server = FastMCP.from_fastapi(fastapi_app) assert isinstance(server, FastMCPOpenAPI) assert server.name == "FastAPI App" class TestTools: async def test_list_tools(self, fastmcp_server: FastMCPOpenAPI): """ By default, tools exclude GET methods """ tools = await fastmcp_server._mcp_list_tools() assert len(tools) == 2 assert tools[0].model_dump() == dict( name="create_user_users_post", description=IsStr(regex=r"^Create a new user\..*$", regex_flags=re.DOTALL), inputSchema={ "type": "object", "properties": { "name": {"type": "string", "title": "Name"}, "active": {"type": "boolean", "title": "Active"}, }, "required": ["name", "active"], }, ) assert tools[1].model_dump() == dict( name="update_user_name_users__user_id__name_patch", description=IsStr( regex=r"^Update a user's name\..*$", regex_flags=re.DOTALL ), inputSchema={ "type": "object", "properties": { "user_id": {"type": "integer", "title": "User Id"}, "name": {"type": "string", "title": "Name"}, }, "required": ["user_id", "name"], }, ) async def test_call_create_user_tool( self, fastmcp_server: FastMCPOpenAPI, api_client ): """ The tool created by the OpenAPI server should be the same as the original """ tool_response = await fastmcp_server.call_tool( "create_user_users_post", {"name": "David", "active": False} ) assert tool_response == User(id=4, name="David", active=False) # Check that the user was created via API response = await api_client.get("/users") assert len(response.json()) == 4 # Check that the user was created via MCP user_response = await fastmcp_server._mcp_read_resource( "resource://openapi/get_user_users__user_id__get/4" ) user = user_response[0].content assert user == tool_response.model_dump() async def test_call_update_user_name_tool( self, fastmcp_server: FastMCPOpenAPI, api_client ): """ The tool created by the OpenAPI server should be the same as the original """ tool_response = await fastmcp_server.call_tool( "update_user_name_users__user_id__name_patch", {"user_id": 1, "name": "XYZ"} ) assert tool_response == dict(id=1, name="XYZ", active=True) # Check that the user was updated via API response = await api_client.get("/users") assert dict(id=1, name="XYZ", active=True) in response.json() # Check that the user was updated via MCP user_response = await fastmcp_server._mcp_read_resource( "resource://openapi/get_user_users__user_id__get/1" ) user = user_response[0].content assert user == tool_response class TestResources: async def test_list_resources(self, fastmcp_server: FastMCPOpenAPI): """ By default, resources exclude GET methods without parameters """ resources = await fastmcp_server._mcp_list_resources() assert len(resources) == 1 assert resources[0].uri == AnyUrl("resource://openapi/get_users_users_get") assert resources[0].name == "get_users_users_get" async def test_get_resource( self, fastmcp_server: FastMCPOpenAPI, api_client, users_db: dict[int, User] ): """ The resource created by the OpenAPI server should be the same as the original """ json_users = TypeAdapter(list[User]).dump_python( sorted(users_db.values(), key=lambda x: x.id) ) resource_response = await fastmcp_server._mcp_read_resource( "resource://openapi/get_users_users_get" ) resource = resource_response[0].content assert resource == json_users response = await api_client.get("/users") assert response.json() == json_users class TestResourceTemplates: async def test_list_resource_templates(self, fastmcp_server: FastMCPOpenAPI): """ By default, resource templates exclude GET methods without parameters """ resource_templates = await fastmcp_server._mcp_list_resource_templates() assert len(resource_templates) == 1 assert resource_templates[0].name == "get_user_users__user_id__get" assert ( resource_templates[0].uriTemplate == r"resource://openapi/get_user_users__user_id__get/{user_id}" ) async def test_get_resource_template( self, fastmcp_server: FastMCPOpenAPI, api_client, users_db: dict[int, User] ): """ The resource template created by the OpenAPI server should be the same as the original """ user_id = 2 resource_response = await fastmcp_server._mcp_read_resource( f"resource://openapi/get_user_users__user_id__get/{user_id}" ) resource = resource_response[0].content assert resource == users_db[user_id].model_dump() response = await api_client.get(f"/users/{user_id}") assert resource == response.json() class TestPrompts: async def test_list_prompts(self, fastmcp_server: FastMCPOpenAPI): """ By default, there are no prompts. """ prompts = await fastmcp_server._mcp_list_prompts() assert len(prompts) == 0 class TestTagTransfer: """Tests for transferring tags from OpenAPI to MCP objects.""" async def test_tags_transferred_to_tools(self, fastmcp_server: FastMCPOpenAPI): """Test that tags from OpenAPI routes are correctly transferred to Tools.""" # Get internal tools directly (not the public API which returns MCP.Content) tools = fastmcp_server._tool_manager.list_tools() # Find the create_user and update_user_name tools create_user_tool = next( (t for t in tools if t.name == "create_user_users_post"), None ) update_user_tool = next( ( t for t in tools if t.name == "update_user_name_users__user_id__name_patch" ), None, ) assert create_user_tool is not None assert update_user_tool is not None # Check that tags from OpenAPI routes were transferred to the Tool objects assert "users" in create_user_tool.tags assert "create" in create_user_tool.tags assert len(create_user_tool.tags) == 2 assert "users" in update_user_tool.tags assert "update" in update_user_tool.tags assert len(update_user_tool.tags) == 2 async def test_tags_transferred_to_resources(self, fastmcp_server: FastMCPOpenAPI): """Test that tags from OpenAPI routes are correctly transferred to Resources.""" # Get internal resources directly resources = fastmcp_server._resource_manager.list_resources() # Find the get_users resource get_users_resource = next( (r for r in resources if r.name == "get_users_users_get"), None ) assert get_users_resource is not None # Check that tags from OpenAPI routes were transferred to the Resource object assert "users" in get_users_resource.tags assert "list" in get_users_resource.tags assert len(get_users_resource.tags) == 2 async def test_tags_transferred_to_resource_templates( self, fastmcp_server: FastMCPOpenAPI ): """Test that tags from OpenAPI routes are correctly transferred to ResourceTemplates.""" # Get internal resource templates directly templates = fastmcp_server._resource_manager.list_templates() # Find the get_user template get_user_template = next( (t for t in templates if t.name == "get_user_users__user_id__get"), None ) assert get_user_template is not None # Check that tags from OpenAPI routes were transferred to the ResourceTemplate object assert "users" in get_user_template.tags assert "detail" in get_user_template.tags assert len(get_user_template.tags) == 2 async def test_tags_preserved_in_resources_created_from_templates( self, fastmcp_server: FastMCPOpenAPI ): """Test that tags are preserved when creating resources from templates.""" # Get internal resource templates directly templates = fastmcp_server._resource_manager.list_templates() # Find the get_user template get_user_template = next( (t for t in templates if t.name == "get_user_users__user_id__get"), None ) assert get_user_template is not None # Manually create a resource from template params = {"user_id": 1} resource = await get_user_template.create_resource( "resource://openapi/get_user_users__user_id__get/1", params ) # Verify tags are preserved from template to resource assert "users" in resource.tags assert "detail" in resource.tags assert len(resource.tags) == 2