from typing import Annotated import pytest from mcp import McpError from mcp.types import ( TextContent, TextResourceContents, ) from pydantic import Field from fastmcp import Client, FastMCP from fastmcp.exceptions import NotFoundError class TestCreateServer: async def test_create_server(self): mcp = FastMCP(instructions="Server instructions") assert mcp.name == "FastMCP" assert mcp.instructions == "Server instructions" async def test_non_ascii_description(self): """Test that FastMCP handles non-ASCII characters in descriptions correctly""" mcp = FastMCP() @mcp.tool( description=( "🌟 This tool uses emojis and UTF-8 characters: á é í ó ú ñ 漢字 🎉" ) ) def hello_world(name: str = "世界") -> str: return f"¡Hola, {name}! 👋" async with Client(mcp) as client: tools = await client.list_tools() assert len(tools) == 1 tool = tools[0] assert tool.description is not None assert "🌟" in tool.description assert "漢字" in tool.description assert "🎉" in tool.description result = await client.call_tool("hello_world", {}) assert len(result) == 1 content = result[0] assert isinstance(content, TextContent) assert "¡Hola, 世界! 👋" == content.text class TestTools: async def test_mcp_tool_name(self): """Test MCPTool name for add_tool (key != tool.name).""" mcp = FastMCP() @mcp.tool() def fn(x: int) -> int: return x + 1 mcp_tools = await mcp._mcp_list_tools() assert len(mcp_tools) == 1 assert mcp_tools[0].name == "fn" async def test_mcp_tool_custom_name(self): """Test MCPTool name for add_tool (key != tool.name).""" mcp = FastMCP() @mcp.tool(name="custom_name") def fn(x: int) -> int: return x + 1 mcp_tools = await mcp._mcp_list_tools() assert len(mcp_tools) == 1 assert mcp_tools[0].name == "custom_name" async def test_remove_tool_successfully(self): """Test that FastMCP.remove_tool removes the tool from the registry.""" mcp = FastMCP() @mcp.tool(name="adder") def add(a: int, b: int) -> int: return a + b mcp_tools = await mcp.get_tools() assert "adder" in mcp_tools mcp.remove_tool("adder") mcp_tools = await mcp.get_tools() assert "adder" not in mcp_tools with pytest.raises(NotFoundError, match="Unknown tool: adder"): await mcp._mcp_call_tool("adder", {"a": 1, "b": 2}) class TestToolDecorator: async def test_no_tools_before_decorator(self): mcp = FastMCP() with pytest.raises(NotFoundError, match="Unknown tool: add"): await mcp._mcp_call_tool("add", {"x": 1, "y": 2}) async def test_tool_decorator(self): mcp = FastMCP() @mcp.tool() def add(x: int, y: int) -> int: return x + y result = await mcp._mcp_call_tool("add", {"x": 1, "y": 2}) assert isinstance(result[0], TextContent) assert result[0].text == "3" async def test_tool_decorator_incorrect_usage(self): mcp = FastMCP() with pytest.raises(TypeError, match="The @tool decorator was used incorrectly"): @mcp.tool # Missing parentheses #type: ignore def add(x: int, y: int) -> int: return x + y async def test_tool_decorator_with_name(self): mcp = FastMCP() @mcp.tool(name="custom-add") def add(x: int, y: int) -> int: return x + y result = await mcp._mcp_call_tool("custom-add", {"x": 1, "y": 2}) assert isinstance(result[0], TextContent) assert result[0].text == "3" async def test_tool_decorator_with_description(self): mcp = FastMCP() @mcp.tool(description="Add two numbers") def add(x: int, y: int) -> int: return x + y tools = await mcp._mcp_list_tools() assert len(tools) == 1 tool = tools[0] assert tool.description == "Add two numbers" async def test_tool_decorator_instance_method(self): mcp = FastMCP() class MyClass: def __init__(self, x: int): self.x = x @mcp.tool() def add(self, y: int) -> int: return self.x + y obj = MyClass(10) mcp.add_tool(obj.add) result = await mcp._mcp_call_tool("add", {"y": 2}) assert isinstance(result[0], TextContent) assert result[0].text == "12" async def test_tool_decorator_classmethod(self): mcp = FastMCP() class MyClass: x: int = 10 @classmethod def add(cls, y: int) -> int: return cls.x + y mcp.add_tool(MyClass.add) result = await mcp._mcp_call_tool("add", {"y": 2}) assert isinstance(result[0], TextContent) assert result[0].text == "12" async def test_tool_decorator_staticmethod(self): mcp = FastMCP() class MyClass: @staticmethod @mcp.tool() def add(x: int, y: int) -> int: return x + y result = await mcp._mcp_call_tool("add", {"x": 1, "y": 2}) assert isinstance(result[0], TextContent) assert result[0].text == "3" async def test_tool_decorator_async_function(self): mcp = FastMCP() @mcp.tool() async def add(x: int, y: int) -> int: return x + y result = await mcp._mcp_call_tool("add", {"x": 1, "y": 2}) assert isinstance(result[0], TextContent) assert result[0].text == "3" async def test_tool_decorator_classmethod_async_function(self): mcp = FastMCP() class MyClass: x = 10 @classmethod async def add(cls, y: int) -> int: return cls.x + y mcp.add_tool(MyClass.add) result = await mcp._mcp_call_tool("add", {"y": 2}) assert isinstance(result[0], TextContent) assert result[0].text == "12" async def test_tool_decorator_staticmethod_async_function(self): mcp = FastMCP() class MyClass: @staticmethod async def add(x: int, y: int) -> int: return x + y mcp.add_tool(MyClass.add) result = await mcp._mcp_call_tool("add", {"x": 1, "y": 2}) assert isinstance(result[0], TextContent) assert result[0].text == "3" async def test_tool_decorator_with_tags(self): """Test that the tool decorator properly sets tags.""" mcp = FastMCP() @mcp.tool(tags={"example", "test-tag"}) def sample_tool(x: int) -> int: return x * 2 # Verify the tags were set correctly tools = mcp._tool_manager.list_tools() assert len(tools) == 1 assert tools[0].tags == {"example", "test-tag"} async def test_add_tool_with_custom_name(self): """Test adding a tool with a custom name using server.add_tool().""" mcp = FastMCP() def multiply(a: int, b: int) -> int: """Multiply two numbers.""" return a * b mcp.add_tool(multiply, name="custom_multiply") # Check that the tool is registered with the custom name tools = await mcp.get_tools() assert "custom_multiply" in tools # Call the tool by its custom name result = await mcp._mcp_call_tool("custom_multiply", {"a": 5, "b": 3}) assert isinstance(result[0], TextContent) assert result[0].text == "15" # Original name should not be registered assert "multiply" not in tools async def test_tool_with_annotated_arguments(self): """Test that tools with annotated arguments work correctly.""" mcp = FastMCP() @mcp.tool() def add( x: Annotated[int, Field(description="x is an int")], y: Annotated[str, Field(description="y is not an int")], ) -> None: pass tool = (await mcp.get_tools())["add"] assert tool.parameters["properties"]["x"]["description"] == "x is an int" assert tool.parameters["properties"]["y"]["description"] == "y is not an int" async def test_tool_with_field_defaults(self): """Test that tools with annotated arguments work correctly.""" mcp = FastMCP() @mcp.tool() def add( x: int = Field(description="x is an int"), y: str = Field(description="y is not an int"), ) -> None: pass tool = (await mcp.get_tools())["add"] assert tool.parameters["properties"]["x"]["description"] == "x is an int" assert tool.parameters["properties"]["y"]["description"] == "y is not an int" class TestResourceDecorator: async def test_no_resources_before_decorator(self): mcp = FastMCP() with pytest.raises(McpError, match="Unknown resource"): async with Client(mcp) as client: await client.read_resource("resource://data") async def test_resource_decorator(self): mcp = FastMCP() @mcp.resource("resource://data") def get_data() -> str: return "Hello, world!" async with Client(mcp) as client: result = await client.read_resource("resource://data") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Hello, world!" async def test_resource_decorator_incorrect_usage(self): mcp = FastMCP() with pytest.raises( TypeError, match="The @resource decorator was used incorrectly" ): @mcp.resource # Missing parentheses #type: ignore def get_data() -> str: return "Hello, world!" async def test_resource_decorator_with_name(self): mcp = FastMCP() @mcp.resource("resource://data", name="custom-data") def get_data() -> str: return "Hello, world!" resources_dict = await mcp.get_resources() resources = list(resources_dict.values()) assert len(resources) == 1 assert resources[0].name == "custom-data" async with Client(mcp) as client: result = await client.read_resource("resource://data") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Hello, world!" async def test_resource_decorator_with_description(self): mcp = FastMCP() @mcp.resource("resource://data", description="Data resource") def get_data() -> str: return "Hello, world!" resources_dict = await mcp.get_resources() resources = list(resources_dict.values()) assert len(resources) == 1 assert resources[0].description == "Data resource" async def test_resource_decorator_with_tags(self): """Test that the resource decorator properly sets tags.""" mcp = FastMCP() @mcp.resource("resource://data", tags={"example", "test-tag"}) def get_data() -> str: return "Hello, world!" resources_dict = await mcp.get_resources() resources = list(resources_dict.values()) assert len(resources) == 1 assert resources[0].tags == {"example", "test-tag"} async def test_resource_decorator_instance_method(self): mcp = FastMCP() class MyClass: def __init__(self, prefix: str): self.prefix = prefix def get_data(self) -> str: return f"{self.prefix} Hello, world!" obj = MyClass("My prefix:") mcp.add_resource_fn( obj.get_data, uri="resource://data", name="instance-resource" ) async with Client(mcp) as client: result = await client.read_resource("resource://data") assert isinstance(result[0], TextResourceContents) assert result[0].text == "My prefix: Hello, world!" async def test_resource_decorator_classmethod(self): mcp = FastMCP() class MyClass: prefix = "Class prefix:" @classmethod def get_data(cls) -> str: return f"{cls.prefix} Hello, world!" mcp.add_resource_fn( MyClass.get_data, uri="resource://data", name="class-resource" ) async with Client(mcp) as client: result = await client.read_resource("resource://data") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Class prefix: Hello, world!" async def test_resource_decorator_staticmethod(self): mcp = FastMCP() class MyClass: @staticmethod @mcp.resource("resource://data") def get_data() -> str: return "Static Hello, world!" async with Client(mcp) as client: result = await client.read_resource("resource://data") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Static Hello, world!" async def test_resource_decorator_async_function(self): mcp = FastMCP() @mcp.resource("resource://data") async def get_data() -> str: return "Async Hello, world!" async with Client(mcp) as client: result = await client.read_resource("resource://data") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Async Hello, world!" class TestTemplateDecorator: async def test_template_decorator(self): mcp = FastMCP() @mcp.resource("resource://{name}/data") def get_data(name: str) -> str: return f"Data for {name}" templates_dict = await mcp.get_resource_templates() templates = list(templates_dict.values()) assert len(templates) == 1 assert templates[0].name == "get_data" assert templates[0].uri_template == "resource://{name}/data" async with Client(mcp) as client: result = await client.read_resource("resource://test/data") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Data for test" async def test_template_decorator_incorrect_usage(self): mcp = FastMCP() with pytest.raises( TypeError, match="The @resource decorator was used incorrectly" ): @mcp.resource # Missing parentheses #type: ignore def get_data(name: str) -> str: return f"Data for {name}" async def test_template_decorator_with_name(self): mcp = FastMCP() @mcp.resource("resource://{name}/data", name="custom-template") def get_data(name: str) -> str: return f"Data for {name}" templates_dict = await mcp.get_resource_templates() templates = list(templates_dict.values()) assert len(templates) == 1 assert templates[0].name == "custom-template" async with Client(mcp) as client: result = await client.read_resource("resource://test/data") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Data for test" async def test_template_decorator_with_description(self): mcp = FastMCP() @mcp.resource("resource://{name}/data", description="Template description") def get_data(name: str) -> str: return f"Data for {name}" templates_dict = await mcp.get_resource_templates() templates = list(templates_dict.values()) assert len(templates) == 1 assert templates[0].description == "Template description" async def test_template_decorator_instance_method(self): mcp = FastMCP() class MyClass: def __init__(self, prefix: str): self.prefix = prefix def get_data(self, name: str) -> str: return f"{self.prefix} Data for {name}" obj = MyClass("My prefix:") mcp.add_resource_fn( obj.get_data, uri="resource://{name}/data", name="instance-template" ) async with Client(mcp) as client: result = await client.read_resource("resource://test/data") assert isinstance(result[0], TextResourceContents) assert result[0].text == "My prefix: Data for test" async def test_template_decorator_classmethod(self): mcp = FastMCP() class MyClass: prefix = "Class prefix:" @classmethod def get_data(cls, name: str) -> str: return f"{cls.prefix} Data for {name}" mcp.add_resource_fn( MyClass.get_data, uri="resource://{name}/data", name="class-template", ) async with Client(mcp) as client: result = await client.read_resource("resource://test/data") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Class prefix: Data for test" async def test_template_decorator_staticmethod(self): mcp = FastMCP() class MyClass: @staticmethod @mcp.resource("resource://{name}/data") def get_data(name: str) -> str: return f"Static Data for {name}" async with Client(mcp) as client: result = await client.read_resource("resource://test/data") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Static Data for test" async def test_template_decorator_async_function(self): mcp = FastMCP() @mcp.resource("resource://{name}/data") async def get_data(name: str) -> str: return f"Async Data for {name}" async with Client(mcp) as client: result = await client.read_resource("resource://test/data") assert isinstance(result[0], TextResourceContents) assert result[0].text == "Async Data for test" async def test_template_decorator_with_tags(self): """Test that the template decorator properly sets tags.""" mcp = FastMCP() @mcp.resource("resource://{param}", tags={"template", "test-tag"}) def template_resource(param: str) -> str: return f"Template resource: {param}" templates_dict = await mcp.get_resource_templates() template = templates_dict["resource://{param}"] assert template.tags == {"template", "test-tag"} async def test_template_decorator_wildcard_param(self): mcp = FastMCP() @mcp.resource("resource://{param*}") def template_resource(param: str) -> str: return f"Template resource: {param}" templates_dict = await mcp.get_resource_templates() template = templates_dict["resource://{param*}"] assert template.uri_template == "resource://{param*}" assert template.name == "template_resource" class TestPromptDecorator: async def test_prompt_decorator(self): mcp = FastMCP() @mcp.prompt() def fn() -> str: return "Hello, world!" prompts_dict = await mcp.get_prompts() assert len(prompts_dict) == 1 prompt = prompts_dict["fn"] assert prompt.name == "fn" # Don't compare functions directly since validate_call wraps them content = await prompt.render() assert isinstance(content[0].content, TextContent) assert content[0].content.text == "Hello, world!" async def test_prompt_decorator_incorrect_usage(self): mcp = FastMCP() with pytest.raises( TypeError, match="The @prompt decorator was used incorrectly" ): @mcp.prompt # Missing parentheses #type: ignore def fn() -> str: return "Hello, world!" async def test_prompt_decorator_with_name(self): mcp = FastMCP() @mcp.prompt(name="custom_name") def fn() -> str: return "Hello, world!" prompts_dict = await mcp.get_prompts() assert len(prompts_dict) == 1 prompt = prompts_dict["custom_name"] assert prompt.name == "custom_name" content = await prompt.render() assert isinstance(content[0].content, TextContent) assert content[0].content.text == "Hello, world!" async def test_prompt_decorator_with_description(self): mcp = FastMCP() @mcp.prompt(description="A custom description") def fn() -> str: return "Hello, world!" prompts_dict = await mcp.get_prompts() assert len(prompts_dict) == 1 prompt = prompts_dict["fn"] assert prompt.description == "A custom description" content = await prompt.render() assert isinstance(content[0].content, TextContent) assert content[0].content.text == "Hello, world!" async def test_prompt_decorator_with_parameters(self): mcp = FastMCP() @mcp.prompt() def test_prompt(name: str, greeting: str = "Hello") -> str: return f"{greeting}, {name}!" prompts_dict = await mcp.get_prompts() assert len(prompts_dict) == 1 prompt = prompts_dict["test_prompt"] assert prompt.arguments is not None assert len(prompt.arguments) == 2 assert prompt.arguments[0].name == "name" assert prompt.arguments[0].required is True assert prompt.arguments[1].name == "greeting" assert prompt.arguments[1].required is False async with Client(mcp) as client: result = await client.get_prompt("test_prompt", {"name": "World"}) assert len(result.messages) == 1 message = result.messages[0] assert isinstance(message.content, TextContent) assert message.content.text == "Hello, World!" result = await client.get_prompt( "test_prompt", {"name": "World", "greeting": "Hi"} ) assert len(result.messages) == 1 message = result.messages[0] assert isinstance(message.content, TextContent) assert message.content.text == "Hi, World!" async def test_prompt_decorator_instance_method(self): mcp = FastMCP() class MyClass: def __init__(self, prefix: str): self.prefix = prefix def test_prompt(self) -> str: return f"{self.prefix} Hello, world!" obj = MyClass("My prefix:") mcp.add_prompt(obj.test_prompt, name="test_prompt") async with Client(mcp) as client: result = await client.get_prompt("test_prompt") assert len(result.messages) == 1 message = result.messages[0] assert isinstance(message.content, TextContent) assert message.content.text == "My prefix: Hello, world!" async def test_prompt_decorator_classmethod(self): mcp = FastMCP() class MyClass: prefix = "Class prefix:" @classmethod def test_prompt(cls) -> str: return f"{cls.prefix} Hello, world!" mcp.add_prompt(MyClass.test_prompt, name="test_prompt") async with Client(mcp) as client: result = await client.get_prompt("test_prompt") assert len(result.messages) == 1 message = result.messages[0] assert isinstance(message.content, TextContent) assert message.content.text == "Class prefix: Hello, world!" async def test_prompt_decorator_staticmethod(self): mcp = FastMCP() class MyClass: @staticmethod @mcp.prompt() def test_prompt() -> str: return "Static Hello, world!" async with Client(mcp) as client: result = await client.get_prompt("test_prompt") assert len(result.messages) == 1 message = result.messages[0] assert isinstance(message.content, TextContent) assert message.content.text == "Static Hello, world!" async def test_prompt_decorator_async_function(self): mcp = FastMCP() @mcp.prompt() async def test_prompt() -> str: return "Async Hello, world!" async with Client(mcp) as client: result = await client.get_prompt("test_prompt") assert len(result.messages) == 1 message = result.messages[0] assert isinstance(message.content, TextContent) assert message.content.text == "Async Hello, world!" async def test_prompt_decorator_with_tags(self): """Test that the prompt decorator properly sets tags.""" mcp = FastMCP() @mcp.prompt(tags={"example", "test-tag"}) def sample_prompt() -> str: return "Hello, world!" prompts_dict = await mcp.get_prompts() assert len(prompts_dict) == 1 prompt = prompts_dict["sample_prompt"] assert prompt.tags == {"example", "test-tag"}