modelcontextprotocol--python-sdk/tests/server/fastmcp/test_server.py

import base64
from pathlib import Path
from typing import TYPE_CHECKING, Any
from unittest.mock import patch

import httpx
import pytest
from pydantic import AnyUrl, BaseModel
from starlette.routing import Mount, Route

from mcp.server.fastmcp import Context, FastMCP
from mcp.server.fastmcp.prompts.base import Message, UserMessage
from mcp.server.fastmcp.resources import FileResource, FunctionResource
from mcp.server.fastmcp.server import Settings
from mcp.server.fastmcp.utilities.types import Audio, Image
from mcp.server.session import ServerSession
from mcp.server.transport_security import TransportSecuritySettings
from mcp.shared.exceptions import McpError
from mcp.shared.memory import (
    create_connected_server_and_client_session as client_session,
)
from mcp.types import (
    AudioContent,
    BlobResourceContents,
    ContentBlock,
    EmbeddedResource,
    ImageContent,
    TextContent,
    TextResourceContents,
)

if TYPE_CHECKING:
    from mcp.server.fastmcp import Context


def test_settings_model_is_complete_at_import():
    """The Settings model resolves its FastMCP annotation at import, so building one needs no deferred rebuild."""
    assert Settings.__pydantic_complete__


class TestServer:
    @pytest.mark.anyio
    async def test_create_server(self):
        mcp = FastMCP(instructions="Server instructions")
        assert mcp.name == "FastMCP"
        assert mcp.instructions == "Server instructions"

    @pytest.mark.anyio
    async def test_normalize_path(self):
        """Test path normalization for mount paths."""
        mcp = FastMCP()

        # Test root path
        assert mcp._normalize_path("/", "/messages/") == "/messages/"

        # Test path with trailing slash
        assert mcp._normalize_path("/github/", "/messages/") == "/github/messages/"

        # Test path without trailing slash
        assert mcp._normalize_path("/github", "/messages/") == "/github/messages/"

        # Test endpoint without leading slash
        assert mcp._normalize_path("/github", "messages/") == "/github/messages/"

        # Test both with trailing/leading slashes
        assert mcp._normalize_path("/api/", "/v1/") == "/api/v1/"

    @pytest.mark.anyio
    async def test_sse_app_with_mount_path(self):
        """Test SSE app creation with different mount paths."""
        # Test with default mount path
        mcp = FastMCP()
        with patch.object(mcp, "_normalize_path", return_value="/messages/") as mock_normalize:
            mcp.sse_app()
            # Verify _normalize_path was called with correct args
            mock_normalize.assert_called_once_with("/", "/messages/")

        # Test with custom mount path in settings
        mcp = FastMCP()
        mcp.settings.mount_path = "/custom"
        with patch.object(mcp, "_normalize_path", return_value="/custom/messages/") as mock_normalize:
            mcp.sse_app()
            # Verify _normalize_path was called with correct args
            mock_normalize.assert_called_once_with("/custom", "/messages/")

        # Test with mount_path parameter
        mcp = FastMCP()
        with patch.object(mcp, "_normalize_path", return_value="/param/messages/") as mock_normalize:
            mcp.sse_app(mount_path="/param")
            # Verify _normalize_path was called with correct args
            mock_normalize.assert_called_once_with("/param", "/messages/")

    @pytest.mark.anyio
    async def test_starlette_routes_with_mount_path(self):
        """Test that Starlette routes are correctly configured with mount path."""
        # Test with mount path in settings
        mcp = FastMCP()
        mcp.settings.mount_path = "/api"
        app = mcp.sse_app()

        # Find routes by type
        sse_routes = [r for r in app.routes if isinstance(r, Route)]
        mount_routes = [r for r in app.routes if isinstance(r, Mount)]

        # Verify routes exist
        assert len(sse_routes) == 1, "Should have one SSE route"
        assert len(mount_routes) == 1, "Should have one mount route"

        # Verify path values
        assert sse_routes[0].path == "/sse", "SSE route path should be /sse"
        assert mount_routes[0].path == "/messages", "Mount route path should be /messages"

        # Test with mount path as parameter
        mcp = FastMCP()
        app = mcp.sse_app(mount_path="/param")

        # Find routes by type
        sse_routes = [r for r in app.routes if isinstance(r, Route)]
        mount_routes = [r for r in app.routes if isinstance(r, Mount)]

        # Verify routes exist
        assert len(sse_routes) == 1, "Should have one SSE route"
        assert len(mount_routes) == 1, "Should have one mount route"

        # Verify path values
        assert sse_routes[0].path == "/sse", "SSE route path should be /sse"
        assert mount_routes[0].path == "/messages", "Mount route path should be /messages"

    @pytest.mark.anyio
    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_session(mcp._mcp_server) as client:
            tools = await client.list_tools()
            assert len(tools.tools) == 1
            tool = tools.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.content) == 1
            content = result.content[0]
            assert isinstance(content, TextContent)
            assert "¡Hola, 世界! 👋" == content.text

    @pytest.mark.anyio
    async def test_add_tool_decorator(self):
        mcp = FastMCP()

        @mcp.tool()
        def sum(x: int, y: int) -> int:  # pragma: no cover
            return x + y

        assert len(mcp._tool_manager.list_tools()) == 1

    @pytest.mark.anyio
    async def test_add_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 sum(x: int, y: int) -> int:  # pragma: no cover
                return x + y

    @pytest.mark.anyio
    async def test_add_resource_decorator(self):
        mcp = FastMCP()

        @mcp.resource("r://{x}")
        def get_data(x: str) -> str:  # pragma: no cover
            return f"Data: {x}"

        assert len(mcp._resource_manager._templates) == 1

    @pytest.mark.anyio
    async def test_add_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(x: str) -> str:  # pragma: no cover
                return f"Data: {x}"


class TestDnsRebindingProtection:
    """Tests for automatic DNS rebinding protection on localhost."""

    def test_auto_enabled_for_127_0_0_1(self):
        """DNS rebinding protection should auto-enable for host=127.0.0.1."""
        mcp = FastMCP(host="127.0.0.1")
        assert mcp.settings.transport_security is not None
        assert mcp.settings.transport_security.enable_dns_rebinding_protection is True
        assert "127.0.0.1:*" in mcp.settings.transport_security.allowed_hosts
        assert "localhost:*" in mcp.settings.transport_security.allowed_hosts
        assert "http://127.0.0.1:*" in mcp.settings.transport_security.allowed_origins
        assert "http://localhost:*" in mcp.settings.transport_security.allowed_origins

    def test_auto_enabled_for_localhost(self):
        """DNS rebinding protection should auto-enable for host=localhost."""
        mcp = FastMCP(host="localhost")
        assert mcp.settings.transport_security is not None
        assert mcp.settings.transport_security.enable_dns_rebinding_protection is True
        assert "127.0.0.1:*" in mcp.settings.transport_security.allowed_hosts
        assert "localhost:*" in mcp.settings.transport_security.allowed_hosts

    def test_auto_enabled_for_ipv6_localhost(self):
        """DNS rebinding protection should auto-enable for host=::1 (IPv6 localhost)."""
        mcp = FastMCP(host="::1")
        assert mcp.settings.transport_security is not None
        assert mcp.settings.transport_security.enable_dns_rebinding_protection is True
        assert "[::1]:*" in mcp.settings.transport_security.allowed_hosts
        assert "http://[::1]:*" in mcp.settings.transport_security.allowed_origins

    def test_not_auto_enabled_for_other_hosts(self):
        """DNS rebinding protection should NOT auto-enable for other hosts."""
        mcp = FastMCP(host="0.0.0.0")
        assert mcp.settings.transport_security is None

    def test_explicit_settings_not_overridden(self):
        """Explicit transport_security settings should not be overridden."""
        custom_settings = TransportSecuritySettings(
            enable_dns_rebinding_protection=False,
        )
        mcp = FastMCP(host="127.0.0.1", transport_security=custom_settings)
        # Settings are copied by pydantic, so check values not identity
        assert mcp.settings.transport_security is not None
        assert mcp.settings.transport_security.enable_dns_rebinding_protection is False
        assert mcp.settings.transport_security.allowed_hosts == []


def tool_fn(x: int, y: int) -> int:
    return x + y


def error_tool_fn() -> None:
    raise ValueError("Test error")


def image_tool_fn(path: str) -> Image:
    return Image(path)


def audio_tool_fn(path: str) -> Audio:
    return Audio(path)


def mixed_content_tool_fn() -> list[ContentBlock]:
    return [
        TextContent(type="text", text="Hello"),
        ImageContent(type="image", data="abc", mimeType="image/png"),
        AudioContent(type="audio", data="def", mimeType="audio/wav"),
    ]


class TestServerTools:
    @pytest.mark.anyio
    async def test_add_tool(self):
        mcp = FastMCP()
        mcp.add_tool(tool_fn)
        mcp.add_tool(tool_fn)
        assert len(mcp._tool_manager.list_tools()) == 1

    @pytest.mark.anyio
    async def test_list_tools(self):
        mcp = FastMCP()
        mcp.add_tool(tool_fn)
        async with client_session(mcp._mcp_server) as client:
            tools = await client.list_tools()
            assert len(tools.tools) == 1

    @pytest.mark.anyio
    async def test_call_tool(self):
        mcp = FastMCP()
        mcp.add_tool(tool_fn)
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("my_tool", {"arg1": "value"})
            assert not hasattr(result, "error")
            assert len(result.content) > 0

    @pytest.mark.anyio
    async def test_tool_exception_handling(self):
        mcp = FastMCP()
        mcp.add_tool(error_tool_fn)
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("error_tool_fn", {})
            assert len(result.content) == 1
            content = result.content[0]
            assert isinstance(content, TextContent)
            assert "Test error" in content.text
            assert result.isError is True

    @pytest.mark.anyio
    async def test_tool_error_handling(self):
        mcp = FastMCP()
        mcp.add_tool(error_tool_fn)
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("error_tool_fn", {})
            assert len(result.content) == 1
            content = result.content[0]
            assert isinstance(content, TextContent)
            assert "Test error" in content.text
            assert result.isError is True

    @pytest.mark.anyio
    async def test_tool_error_details(self):
        """Test that exception details are properly formatted in the response"""
        mcp = FastMCP()
        mcp.add_tool(error_tool_fn)
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("error_tool_fn", {})
            content = result.content[0]
            assert isinstance(content, TextContent)
            assert isinstance(content.text, str)
            assert "Test error" in content.text
            assert result.isError is True

    @pytest.mark.anyio
    async def test_tool_return_value_conversion(self):
        mcp = FastMCP()
        mcp.add_tool(tool_fn)
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("tool_fn", {"x": 1, "y": 2})
            assert len(result.content) == 1
            content = result.content[0]
            assert isinstance(content, TextContent)
            assert content.text == "3"
            # Check structured content - int return type should have structured output
            assert result.structuredContent is not None
            assert result.structuredContent == {"result": 3}

    @pytest.mark.anyio
    async def test_tool_image_helper(self, tmp_path: Path):
        # Create a test image
        image_path = tmp_path / "test.png"
        image_path.write_bytes(b"fake png data")

        mcp = FastMCP()
        mcp.add_tool(image_tool_fn)
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("image_tool_fn", {"path": str(image_path)})
            assert len(result.content) == 1
            content = result.content[0]
            assert isinstance(content, ImageContent)
            assert content.type == "image"
            assert content.mimeType == "image/png"
            # Verify base64 encoding
            decoded = base64.b64decode(content.data)
            assert decoded == b"fake png data"
            # Check structured content - Image return type should NOT have structured output
            assert result.structuredContent is None

    @pytest.mark.anyio
    async def test_tool_audio_helper(self, tmp_path: Path):
        # Create a test audio
        audio_path = tmp_path / "test.wav"
        audio_path.write_bytes(b"fake wav data")

        mcp = FastMCP()
        mcp.add_tool(audio_tool_fn)
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("audio_tool_fn", {"path": str(audio_path)})
            assert len(result.content) == 1
            content = result.content[0]
            assert isinstance(content, AudioContent)
            assert content.type == "audio"
            assert content.mimeType == "audio/wav"
            # Verify base64 encoding
            decoded = base64.b64decode(content.data)
            assert decoded == b"fake wav data"
            # Check structured content - Image return type should NOT have structured output
            assert result.structuredContent is None

    @pytest.mark.parametrize(
        "filename,expected_mime_type",
        [
            ("test.wav", "audio/wav"),
            ("test.mp3", "audio/mpeg"),
            ("test.ogg", "audio/ogg"),
            ("test.flac", "audio/flac"),
            ("test.aac", "audio/aac"),
            ("test.m4a", "audio/mp4"),
            ("test.unknown", "application/octet-stream"),  # Unknown extension fallback
        ],
    )
    @pytest.mark.anyio
    async def test_tool_audio_suffix_detection(self, tmp_path: Path, filename: str, expected_mime_type: str):
        """Test that Audio helper correctly detects MIME types from file suffixes"""
        mcp = FastMCP()
        mcp.add_tool(audio_tool_fn)

        # Create a test audio file with the specific extension
        audio_path = tmp_path / filename
        audio_path.write_bytes(b"fake audio data")

        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("audio_tool_fn", {"path": str(audio_path)})
            assert len(result.content) == 1
            content = result.content[0]
            assert isinstance(content, AudioContent)
            assert content.type == "audio"
            assert content.mimeType == expected_mime_type
            # Verify base64 encoding
            decoded = base64.b64decode(content.data)
            assert decoded == b"fake audio data"

    @pytest.mark.anyio
    async def test_tool_mixed_content(self):
        mcp = FastMCP()
        mcp.add_tool(mixed_content_tool_fn)
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("mixed_content_tool_fn", {})
            assert len(result.content) == 3
            content1, content2, content3 = result.content
            assert isinstance(content1, TextContent)
            assert content1.text == "Hello"
            assert isinstance(content2, ImageContent)
            assert content2.mimeType == "image/png"
            assert content2.data == "abc"
            assert isinstance(content3, AudioContent)
            assert content3.mimeType == "audio/wav"
            assert content3.data == "def"
            assert result.structuredContent is not None
            assert "result" in result.structuredContent
            structured_result = result.structuredContent["result"]
            assert len(structured_result) == 3

            expected_content = [
                {"type": "text", "text": "Hello"},
                {"type": "image", "data": "abc", "mimeType": "image/png"},
                {"type": "audio", "data": "def", "mimeType": "audio/wav"},
            ]

            for i, expected in enumerate(expected_content):
                for key, value in expected.items():
                    assert structured_result[i][key] == value

    @pytest.mark.anyio
    async def test_tool_mixed_list_with_audio_and_image(self, tmp_path: Path):
        """Test that lists containing Image objects and other types are handled
        correctly"""
        # Create a test image
        image_path = tmp_path / "test.png"
        image_path.write_bytes(b"test image data")

        # Create a test audio
        audio_path = tmp_path / "test.wav"
        audio_path.write_bytes(b"test audio data")

        # TODO(Marcelo): It seems if we add the proper type hint, it generates an invalid JSON schema.
        # We need to fix this.
        def mixed_list_fn() -> list:  # type: ignore
            return [  # type: ignore
                "text message",
                Image(image_path),
                Audio(audio_path),
                {"key": "value"},
                TextContent(type="text", text="direct content"),
            ]

        mcp = FastMCP()
        mcp.add_tool(mixed_list_fn)  # type: ignore
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("mixed_list_fn", {})
            assert len(result.content) == 5
            # Check text conversion
            content1 = result.content[0]
            assert isinstance(content1, TextContent)
            assert content1.text == "text message"
            # Check image conversion
            content2 = result.content[1]
            assert isinstance(content2, ImageContent)
            assert content2.mimeType == "image/png"
            assert base64.b64decode(content2.data) == b"test image data"
            # Check audio conversion
            content3 = result.content[2]
            assert isinstance(content3, AudioContent)
            assert content3.mimeType == "audio/wav"
            assert base64.b64decode(content3.data) == b"test audio data"
            # Check dict conversion
            content4 = result.content[3]
            assert isinstance(content4, TextContent)
            assert '"key": "value"' in content4.text
            # Check direct TextContent
            content5 = result.content[4]
            assert isinstance(content5, TextContent)
            assert content5.text == "direct content"
            # Check structured content - untyped list with Image objects should NOT have structured output
            assert result.structuredContent is None

    @pytest.mark.anyio
    async def test_tool_structured_output_basemodel(self):
        """Test tool with structured output returning BaseModel"""

        class UserOutput(BaseModel):
            name: str
            age: int
            active: bool = True

        def get_user(user_id: int) -> UserOutput:
            """Get user by ID"""
            return UserOutput(name="John Doe", age=30)

        mcp = FastMCP()
        mcp.add_tool(get_user)

        async with client_session(mcp._mcp_server) as client:
            # Check that the tool has outputSchema
            tools = await client.list_tools()
            tool = next(t for t in tools.tools if t.name == "get_user")
            assert tool.outputSchema is not None
            assert tool.outputSchema["type"] == "object"
            assert "name" in tool.outputSchema["properties"]
            assert "age" in tool.outputSchema["properties"]

            # Call the tool and check structured output
            result = await client.call_tool("get_user", {"user_id": 123})
            assert result.isError is False
            assert result.structuredContent is not None
            assert result.structuredContent == {"name": "John Doe", "age": 30, "active": True}
            # Content should be JSON serialized version
            assert len(result.content) == 1
            assert isinstance(result.content[0], TextContent)
            assert '"name": "John Doe"' in result.content[0].text

    @pytest.mark.anyio
    async def test_tool_structured_output_primitive(self):
        """Test tool with structured output returning primitive type"""

        def calculate_sum(a: int, b: int) -> int:
            """Add two numbers"""
            return a + b

        mcp = FastMCP()
        mcp.add_tool(calculate_sum)

        async with client_session(mcp._mcp_server) as client:
            # Check that the tool has outputSchema
            tools = await client.list_tools()
            tool = next(t for t in tools.tools if t.name == "calculate_sum")
            assert tool.outputSchema is not None
            # Primitive types are wrapped
            assert tool.outputSchema["type"] == "object"
            assert "result" in tool.outputSchema["properties"]
            assert tool.outputSchema["properties"]["result"]["type"] == "integer"

            # Call the tool
            result = await client.call_tool("calculate_sum", {"a": 5, "b": 7})
            assert result.isError is False
            assert result.structuredContent is not None
            assert result.structuredContent == {"result": 12}

    @pytest.mark.anyio
    async def test_tool_structured_output_list(self):
        """Test tool with structured output returning list"""

        def get_numbers() -> list[int]:
            """Get a list of numbers"""
            return [1, 2, 3, 4, 5]

        mcp = FastMCP()
        mcp.add_tool(get_numbers)

        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("get_numbers", {})
            assert result.isError is False
            assert result.structuredContent is not None
            assert result.structuredContent == {"result": [1, 2, 3, 4, 5]}

    @pytest.mark.anyio
    async def test_tool_structured_output_server_side_validation_error(self):
        """Test that server-side validation errors are handled properly"""

        def get_numbers() -> list[int]:
            return [1, 2, 3, 4, [5]]  # type: ignore

        mcp = FastMCP()
        mcp.add_tool(get_numbers)

        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("get_numbers", {})
            assert result.isError is True
            assert result.structuredContent is None
            assert len(result.content) == 1
            assert isinstance(result.content[0], TextContent)

    @pytest.mark.anyio
    async def test_tool_structured_output_dict_str_any(self):
        """Test tool with dict[str, Any] structured output"""

        def get_metadata() -> dict[str, Any]:
            """Get metadata dictionary"""
            return {
                "version": "1.0.0",
                "enabled": True,
                "count": 42,
                "tags": ["production", "stable"],
                "config": {"nested": {"value": 123}},
            }

        mcp = FastMCP()
        mcp.add_tool(get_metadata)

        async with client_session(mcp._mcp_server) as client:
            # Check schema
            tools = await client.list_tools()
            tool = next(t for t in tools.tools if t.name == "get_metadata")
            assert tool.outputSchema is not None
            assert tool.outputSchema["type"] == "object"
            # dict[str, Any] should have minimal schema
            assert (
                "additionalProperties" not in tool.outputSchema or tool.outputSchema.get("additionalProperties") is True
            )

            # Call tool
            result = await client.call_tool("get_metadata", {})
            assert result.isError is False
            assert result.structuredContent is not None
            expected = {
                "version": "1.0.0",
                "enabled": True,
                "count": 42,
                "tags": ["production", "stable"],
                "config": {"nested": {"value": 123}},
            }
            assert result.structuredContent == expected

    @pytest.mark.anyio
    async def test_tool_structured_output_dict_str_typed(self):
        """Test tool with dict[str, T] structured output for specific T"""

        def get_settings() -> dict[str, str]:
            """Get settings as string dictionary"""
            return {"theme": "dark", "language": "en", "timezone": "UTC"}

        mcp = FastMCP()
        mcp.add_tool(get_settings)

        async with client_session(mcp._mcp_server) as client:
            # Check schema
            tools = await client.list_tools()
            tool = next(t for t in tools.tools if t.name == "get_settings")
            assert tool.outputSchema is not None
            assert tool.outputSchema["type"] == "object"
            assert tool.outputSchema["additionalProperties"]["type"] == "string"

            # Call tool
            result = await client.call_tool("get_settings", {})
            assert result.isError is False
            assert result.structuredContent == {"theme": "dark", "language": "en", "timezone": "UTC"}

    @pytest.mark.anyio
    async def test_remove_tool(self):
        """Test removing a tool from the server."""
        mcp = FastMCP()
        mcp.add_tool(tool_fn)

        # Verify tool exists
        assert len(mcp._tool_manager.list_tools()) == 1

        # Remove the tool
        mcp.remove_tool("tool_fn")

        # Verify tool is removed
        assert len(mcp._tool_manager.list_tools()) == 0

    @pytest.mark.anyio
    async def test_remove_nonexistent_tool(self):
        """Test that removing a non-existent tool raises ToolError."""
        from mcp.server.fastmcp.exceptions import ToolError

        mcp = FastMCP()

        with pytest.raises(ToolError, match="Unknown tool: nonexistent"):
            mcp.remove_tool("nonexistent")

    @pytest.mark.anyio
    async def test_remove_tool_and_list(self):
        """Test that a removed tool doesn't appear in list_tools."""
        mcp = FastMCP()
        mcp.add_tool(tool_fn)
        mcp.add_tool(error_tool_fn)

        # Verify both tools exist
        async with client_session(mcp._mcp_server) as client:
            tools = await client.list_tools()
            assert len(tools.tools) == 2
            tool_names = [t.name for t in tools.tools]
            assert "tool_fn" in tool_names
            assert "error_tool_fn" in tool_names

        # Remove one tool
        mcp.remove_tool("tool_fn")

        # Verify only one tool remains
        async with client_session(mcp._mcp_server) as client:
            tools = await client.list_tools()
            assert len(tools.tools) == 1
            assert tools.tools[0].name == "error_tool_fn"

    @pytest.mark.anyio
    async def test_remove_tool_and_call(self):
        """Test that calling a removed tool fails appropriately."""
        mcp = FastMCP()
        mcp.add_tool(tool_fn)

        # Verify tool works before removal
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("tool_fn", {"x": 1, "y": 2})
            assert not result.isError
            content = result.content[0]
            assert isinstance(content, TextContent)
            assert content.text == "3"

        # Remove the tool
        mcp.remove_tool("tool_fn")

        # Verify calling removed tool returns an error
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("tool_fn", {"x": 1, "y": 2})
            assert result.isError
            content = result.content[0]
            assert isinstance(content, TextContent)
            assert "Unknown tool" in content.text


class TestServerResources:
    @pytest.mark.anyio
    async def test_text_resource(self):
        mcp = FastMCP()

        def get_text():
            return "Hello, world!"

        resource = FunctionResource(uri=AnyUrl("resource://test"), name="test", fn=get_text)
        mcp.add_resource(resource)

        async with client_session(mcp._mcp_server) as client:
            result = await client.read_resource(AnyUrl("resource://test"))
            assert isinstance(result.contents[0], TextResourceContents)
            assert result.contents[0].text == "Hello, world!"

    @pytest.mark.anyio
    async def test_binary_resource(self):
        mcp = FastMCP()

        def get_binary():
            return b"Binary data"

        resource = FunctionResource(
            uri=AnyUrl("resource://binary"),
            name="binary",
            fn=get_binary,
            mime_type="application/octet-stream",
        )
        mcp.add_resource(resource)

        async with client_session(mcp._mcp_server) as client:
            result = await client.read_resource(AnyUrl("resource://binary"))
            assert isinstance(result.contents[0], BlobResourceContents)
            assert result.contents[0].blob == base64.b64encode(b"Binary data").decode()

    @pytest.mark.anyio
    async def test_file_resource_text(self, tmp_path: Path):
        mcp = FastMCP()

        # Create a text file
        text_file = tmp_path / "test.txt"
        text_file.write_text("Hello from file!")

        resource = FileResource(uri=AnyUrl("file://test.txt"), name="test.txt", path=text_file)
        mcp.add_resource(resource)

        async with client_session(mcp._mcp_server) as client:
            result = await client.read_resource(AnyUrl("file://test.txt"))
            assert isinstance(result.contents[0], TextResourceContents)
            assert result.contents[0].text == "Hello from file!"

    @pytest.mark.anyio
    async def test_file_resource_binary(self, tmp_path: Path):
        mcp = FastMCP()

        # Create a binary file
        binary_file = tmp_path / "test.bin"
        binary_file.write_bytes(b"Binary file data")

        resource = FileResource(
            uri=AnyUrl("file://test.bin"),
            name="test.bin",
            path=binary_file,
            mime_type="application/octet-stream",
        )
        mcp.add_resource(resource)

        async with client_session(mcp._mcp_server) as client:
            result = await client.read_resource(AnyUrl("file://test.bin"))
            assert isinstance(result.contents[0], BlobResourceContents)
            assert result.contents[0].blob == base64.b64encode(b"Binary file data").decode()

    @pytest.mark.anyio
    async def test_function_resource(self):
        mcp = FastMCP()

        @mcp.resource("function://test", name="test_get_data")
        def get_data() -> str:  # pragma: no cover
            """get_data returns a string"""
            return "Hello, world!"

        async with client_session(mcp._mcp_server) as client:
            resources = await client.list_resources()
            assert len(resources.resources) == 1
            resource = resources.resources[0]
            assert resource.description == "get_data returns a string"
            assert resource.uri == AnyUrl("function://test")
            assert resource.name == "test_get_data"
            assert resource.mimeType == "text/plain"


class TestServerResourceTemplates:
    @pytest.mark.anyio
    async def test_resource_with_params(self):
        """Test that a resource with function parameters raises an error if the URI
        parameters don't match"""
        mcp = FastMCP()

        with pytest.raises(ValueError, match="Mismatch between URI parameters"):

            @mcp.resource("resource://data")
            def get_data_fn(param: str) -> str:  # pragma: no cover
                return f"Data: {param}"

    @pytest.mark.anyio
    async def test_resource_with_uri_params(self):
        """Test that a resource with URI parameters is automatically a template"""
        mcp = FastMCP()

        with pytest.raises(ValueError, match="Mismatch between URI parameters"):

            @mcp.resource("resource://{param}")
            def get_data() -> str:  # pragma: no cover
                return "Data"

    @pytest.mark.anyio
    async def test_resource_with_untyped_params(self):
        """Test that a resource with untyped parameters raises an error"""
        mcp = FastMCP()

        @mcp.resource("resource://{param}")
        def get_data(param) -> str:  # type: ignore  # pragma: no cover
            return "Data"

    @pytest.mark.anyio
    async def test_resource_matching_params(self):
        """Test that a resource with matching URI and function parameters works"""
        mcp = FastMCP()

        @mcp.resource("resource://{name}/data")
        def get_data(name: str) -> str:
            return f"Data for {name}"

        async with client_session(mcp._mcp_server) as client:
            result = await client.read_resource(AnyUrl("resource://test/data"))
            assert isinstance(result.contents[0], TextResourceContents)
            assert result.contents[0].text == "Data for test"

    @pytest.mark.anyio
    async def test_resource_mismatched_params(self):
        """Test that mismatched parameters raise an error"""
        mcp = FastMCP()

        with pytest.raises(ValueError, match="Mismatch between URI parameters"):

            @mcp.resource("resource://{name}/data")
            def get_data(user: str) -> str:  # pragma: no cover
                return f"Data for {user}"

    @pytest.mark.anyio
    async def test_resource_multiple_params(self):
        """Test that multiple parameters work correctly"""
        mcp = FastMCP()

        @mcp.resource("resource://{org}/{repo}/data")
        def get_data(org: str, repo: str) -> str:
            return f"Data for {org}/{repo}"

        async with client_session(mcp._mcp_server) as client:
            result = await client.read_resource(AnyUrl("resource://cursor/fastmcp/data"))
            assert isinstance(result.contents[0], TextResourceContents)
            assert result.contents[0].text == "Data for cursor/fastmcp"

    @pytest.mark.anyio
    async def test_resource_multiple_mismatched_params(self):
        """Test that mismatched parameters raise an error"""
        mcp = FastMCP()

        with pytest.raises(ValueError, match="Mismatch between URI parameters"):

            @mcp.resource("resource://{org}/{repo}/data")
            def get_data_mismatched(org: str, repo_2: str) -> str:  # pragma: no cover
                return f"Data for {org}"

        """Test that a resource with no parameters works as a regular resource"""  # pragma: no cover
        mcp = FastMCP()

        @mcp.resource("resource://static")
        def get_static_data() -> str:
            return "Static data"

        async with client_session(mcp._mcp_server) as client:
            result = await client.read_resource(AnyUrl("resource://static"))
            assert isinstance(result.contents[0], TextResourceContents)
            assert result.contents[0].text == "Static data"

    @pytest.mark.anyio
    async def test_template_to_resource_conversion(self):
        """Test that templates are properly converted to resources when accessed"""
        mcp = FastMCP()

        @mcp.resource("resource://{name}/data")
        def get_data(name: str) -> str:
            return f"Data for {name}"

        # Should be registered as a template
        assert len(mcp._resource_manager._templates) == 1
        assert len(await mcp.list_resources()) == 0

        # When accessed, should create a concrete resource
        resource = await mcp._resource_manager.get_resource("resource://test/data")
        assert isinstance(resource, FunctionResource)
        result = await resource.read()
        assert result == "Data for test"

    @pytest.mark.anyio
    async def test_resource_template_includes_mime_type(self):
        """Test that list resource templates includes the correct mimeType."""
        mcp = FastMCP()

        @mcp.resource("resource://{user}/csv", mime_type="text/csv")
        def get_csv(user: str) -> str:
            return f"csv for {user}"

        templates = await mcp.list_resource_templates()
        assert len(templates) == 1
        template = templates[0]

        assert hasattr(template, "mimeType")
        assert template.mimeType == "text/csv"

        async with client_session(mcp._mcp_server) as client:
            result = await client.read_resource(AnyUrl("resource://bob/csv"))
            assert isinstance(result.contents[0], TextResourceContents)
            assert result.contents[0].text == "csv for bob"


class TestServerResourceMetadata:
    """Test FastMCP @resource decorator meta parameter for list operations.

    Meta flows: @resource decorator -> resource/template storage -> list_resources/list_resource_templates.
    Note: read_resource does NOT pass meta to protocol response (lowlevel/server.py only extracts content/mime_type).
    """

    @pytest.mark.anyio
    async def test_resource_decorator_with_metadata(self):
        """Test that @resource decorator accepts and passes meta parameter."""
        # Tests static resource flow: decorator -> FunctionResource -> list_resources (server.py:544,635,361)
        mcp = FastMCP()

        metadata = {"ui": {"component": "file-viewer"}, "priority": "high"}

        @mcp.resource("resource://config", meta=metadata)
        def get_config() -> str:  # pragma: no cover
            return '{"debug": false}'

        resources = await mcp.list_resources()
        assert len(resources) == 1
        assert resources[0].meta is not None
        assert resources[0].meta == metadata
        assert resources[0].meta["ui"]["component"] == "file-viewer"
        assert resources[0].meta["priority"] == "high"

    @pytest.mark.anyio
    async def test_resource_template_decorator_with_metadata(self):
        """Test that @resource decorator passes meta to templates."""
        # Tests template resource flow: decorator -> add_template() -> list_resource_templates (server.py:544,622,377)
        mcp = FastMCP()

        metadata = {"api_version": "v2", "deprecated": False}

        @mcp.resource("resource://{city}/weather", meta=metadata)
        def get_weather(city: str) -> str:  # pragma: no cover
            return f"Weather for {city}"

        templates = await mcp.list_resource_templates()
        assert len(templates) == 1
        assert templates[0].meta is not None
        assert templates[0].meta == metadata
        assert templates[0].meta["api_version"] == "v2"

    @pytest.mark.anyio
    async def test_read_resource_returns_meta(self):
        """Test that read_resource includes meta in response."""
        # Tests end-to-end: Resource.meta -> ReadResourceContents.meta -> protocol _meta (lowlevel/server.py:341,371)
        mcp = FastMCP()

        metadata = {"version": "1.0", "category": "config"}

        @mcp.resource("resource://data", meta=metadata)
        def get_data() -> str:
            return "test data"

        async with client_session(mcp._mcp_server) as client:
            result = await client.read_resource(AnyUrl("resource://data"))

            # Verify content and metadata in protocol response
            assert isinstance(result.contents[0], TextResourceContents)
            assert result.contents[0].text == "test data"
            assert result.contents[0].meta is not None
            assert result.contents[0].meta == metadata
            assert result.contents[0].meta["version"] == "1.0"
            assert result.contents[0].meta["category"] == "config"


class TestContextInjection:
    """Test context injection in tools, resources, and prompts."""

    @pytest.mark.anyio
    async def test_context_detection(self):
        """Test that context parameters are properly detected."""
        mcp = FastMCP()

        def tool_with_context(x: int, ctx: Context[ServerSession, None]) -> str:  # pragma: no cover
            return f"Request {ctx.request_id}: {x}"

        tool = mcp._tool_manager.add_tool(tool_with_context)
        assert tool.context_kwarg == "ctx"

    @pytest.mark.anyio
    async def test_context_injection(self):
        """Test that context is properly injected into tool calls."""
        mcp = FastMCP()

        def tool_with_context(x: int, ctx: Context[ServerSession, None]) -> str:
            assert ctx.request_id is not None
            return f"Request {ctx.request_id}: {x}"

        mcp.add_tool(tool_with_context)
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("tool_with_context", {"x": 42})
            assert len(result.content) == 1
            content = result.content[0]
            assert isinstance(content, TextContent)
            assert "Request" in content.text
            assert "42" in content.text

    @pytest.mark.anyio
    async def test_async_context(self):
        """Test that context works in async functions."""
        mcp = FastMCP()

        async def async_tool(x: int, ctx: Context[ServerSession, None]) -> str:
            assert ctx.request_id is not None
            return f"Async request {ctx.request_id}: {x}"

        mcp.add_tool(async_tool)
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("async_tool", {"x": 42})
            assert len(result.content) == 1
            content = result.content[0]
            assert isinstance(content, TextContent)
            assert "Async request" in content.text
            assert "42" in content.text

    @pytest.mark.anyio
    async def test_context_logging(self):
        """Test that context logging methods work."""
        mcp = FastMCP()

        async def logging_tool(msg: str, ctx: Context[ServerSession, None]) -> str:
            await ctx.debug("Debug message")
            await ctx.info("Info message")
            await ctx.warning("Warning message")
            await ctx.error("Error message")
            return f"Logged messages for {msg}"

        mcp.add_tool(logging_tool)

        with patch("mcp.server.session.ServerSession.send_log_message") as mock_log:
            async with client_session(mcp._mcp_server) as client:
                result = await client.call_tool("logging_tool", {"msg": "test"})
                assert len(result.content) == 1
                content = result.content[0]
                assert isinstance(content, TextContent)
                assert "Logged messages for test" in content.text

                assert mock_log.call_count == 4
                mock_log.assert_any_call(
                    level="debug",
                    data="Debug message",
                    logger=None,
                    related_request_id="1",
                )
                mock_log.assert_any_call(
                    level="info",
                    data="Info message",
                    logger=None,
                    related_request_id="1",
                )
                mock_log.assert_any_call(
                    level="warning",
                    data="Warning message",
                    logger=None,
                    related_request_id="1",
                )
                mock_log.assert_any_call(
                    level="error",
                    data="Error message",
                    logger=None,
                    related_request_id="1",
                )

    @pytest.mark.anyio
    async def test_optional_context(self):
        """Test that context is optional."""
        mcp = FastMCP()

        def no_context(x: int) -> int:
            return x * 2

        mcp.add_tool(no_context)
        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("no_context", {"x": 21})
            assert len(result.content) == 1
            content = result.content[0]
            assert isinstance(content, TextContent)
            assert content.text == "42"

    @pytest.mark.anyio
    async def test_context_resource_access(self):
        """Test that context can access resources."""
        mcp = FastMCP()

        @mcp.resource("test://data")
        def test_resource() -> str:
            return "resource data"

        @mcp.tool()
        async def tool_with_resource(ctx: Context[ServerSession, None]) -> str:
            r_iter = await ctx.read_resource("test://data")
            r_list = list(r_iter)
            assert len(r_list) == 1
            r = r_list[0]
            return f"Read resource: {r.content} with mime type {r.mime_type}"

        async with client_session(mcp._mcp_server) as client:
            result = await client.call_tool("tool_with_resource", {})
            assert len(result.content) == 1
            content = result.content[0]
            assert isinstance(content, TextContent)
            assert "Read resource: resource data" in content.text

    @pytest.mark.anyio
    async def test_resource_with_context(self):
        """Test that resources can receive context parameter."""
        mcp = FastMCP()

        @mcp.resource("resource://context/{name}")
        def resource_with_context(name: str, ctx: Context[ServerSession, None]) -> str:
            """Resource that receives context."""
            assert ctx is not None
            return f"Resource {name} - context injected"

        # Verify template has context_kwarg set
        templates = mcp._resource_manager.list_templates()
        assert len(templates) == 1
        template = templates[0]
        assert hasattr(template, "context_kwarg")
        assert template.context_kwarg == "ctx"

        # Test via client
        async with client_session(mcp._mcp_server) as client:
            result = await client.read_resource(AnyUrl("resource://context/test"))
            assert len(result.contents) == 1
            content = result.contents[0]
            assert isinstance(content, TextResourceContents)
            # Should have either request_id or indication that context was injected
            assert "Resource test - context injected" == content.text

    @pytest.mark.anyio
    async def test_resource_without_context(self):
        """Test that resources without context work normally."""
        mcp = FastMCP()

        @mcp.resource("resource://nocontext/{name}")
        def resource_no_context(name: str) -> str:
            """Resource without context."""
            return f"Resource {name} works"

        # Verify template has no context_kwarg
        templates = mcp._resource_manager.list_templates()
        assert len(templates) == 1
        template = templates[0]
        assert template.context_kwarg is None

        # Test via client
        async with client_session(mcp._mcp_server) as client:
            result = await client.read_resource(AnyUrl("resource://nocontext/test"))
            assert len(result.contents) == 1
            content = result.contents[0]
            assert isinstance(content, TextResourceContents)
            assert content.text == "Resource test works"

    @pytest.mark.anyio
    async def test_resource_context_custom_name(self):
        """Test resource context with custom parameter name."""
        mcp = FastMCP()

        @mcp.resource("resource://custom/{id}")
        def resource_custom_ctx(id: str, my_ctx: Context[ServerSession, None]) -> str:
            """Resource with custom context parameter name."""
            assert my_ctx is not None
            return f"Resource {id} with context"

        # Verify template detects custom context parameter
        templates = mcp._resource_manager.list_templates()
        assert len(templates) == 1
        template = templates[0]
        assert template.context_kwarg == "my_ctx"

        # Test via client
        async with client_session(mcp._mcp_server) as client:
            result = await client.read_resource(AnyUrl("resource://custom/123"))
            assert len(result.contents) == 1
            content = result.contents[0]
            assert isinstance(content, TextResourceContents)
            assert "Resource 123 with context" in content.text

    @pytest.mark.anyio
    async def test_prompt_with_context(self):
        """Test that prompts can receive context parameter."""
        mcp = FastMCP()

        @mcp.prompt("prompt_with_ctx")
        def prompt_with_context(text: str, ctx: Context[ServerSession, None]) -> str:
            """Prompt that expects context."""
            assert ctx is not None
            return f"Prompt '{text}' - context injected"

        # Check if prompt has context parameter detection
        prompts = mcp._prompt_manager.list_prompts()
        assert len(prompts) == 1

        # Test via client
        async with client_session(mcp._mcp_server) as client:
            # Try calling without passing ctx explicitly
            result = await client.get_prompt("prompt_with_ctx", {"text": "test"})
            # If this succeeds, check if context was injected
            assert len(result.messages) == 1
            content = result.messages[0].content
            assert isinstance(content, TextContent)
            assert "Prompt 'test' - context injected" in content.text

    @pytest.mark.anyio
    async def test_prompt_without_context(self):
        """Test that prompts without context work normally."""
        mcp = FastMCP()

        @mcp.prompt("prompt_no_ctx")
        def prompt_no_context(text: str) -> str:
            """Prompt without context."""
            return f"Prompt '{text}' works"

        # Test via client
        async with client_session(mcp._mcp_server) as client:
            result = await client.get_prompt("prompt_no_ctx", {"text": "test"})
            assert len(result.messages) == 1
            message = result.messages[0]
            content = message.content
            assert isinstance(content, TextContent)
            assert content.text == "Prompt 'test' works"


class TestServerPrompts:
    """Test prompt functionality in FastMCP server."""

    @pytest.mark.anyio
    async def test_prompt_decorator(self):
        """Test that the prompt decorator registers prompts correctly."""
        mcp = FastMCP()

        @mcp.prompt()
        def fn() -> str:
            return "Hello, world!"

        prompts = mcp._prompt_manager.list_prompts()
        assert len(prompts) == 1
        assert prompts[0].name == "fn"
        # Don't compare functions directly since validate_call wraps them
        content = await prompts[0].render()
        assert isinstance(content[0].content, TextContent)
        assert content[0].content.text == "Hello, world!"

    @pytest.mark.anyio
    async def test_prompt_decorator_with_name(self):
        """Test prompt decorator with custom name."""
        mcp = FastMCP()

        @mcp.prompt(name="custom_name")
        def fn() -> str:
            return "Hello, world!"

        prompts = mcp._prompt_manager.list_prompts()
        assert len(prompts) == 1
        assert prompts[0].name == "custom_name"
        content = await prompts[0].render()
        assert isinstance(content[0].content, TextContent)
        assert content[0].content.text == "Hello, world!"

    @pytest.mark.anyio
    async def test_prompt_decorator_with_description(self):
        """Test prompt decorator with custom description."""
        mcp = FastMCP()

        @mcp.prompt(description="A custom description")
        def fn() -> str:
            return "Hello, world!"

        prompts = mcp._prompt_manager.list_prompts()
        assert len(prompts) == 1
        assert prompts[0].description == "A custom description"
        content = await prompts[0].render()
        assert isinstance(content[0].content, TextContent)
        assert content[0].content.text == "Hello, world!"

    def test_prompt_decorator_error(self):
        """Test error when decorator is used incorrectly."""
        mcp = FastMCP()
        with pytest.raises(TypeError, match="decorator was used incorrectly"):

            @mcp.prompt  # type: ignore
            def fn() -> str:  # pragma: no cover
                return "Hello, world!"

    @pytest.mark.anyio
    async def test_list_prompts(self):
        """Test listing prompts through MCP protocol."""
        mcp = FastMCP()

        @mcp.prompt()
        def fn(name: str, optional: str = "default") -> str:  # pragma: no cover
            return f"Hello, {name}!"

        async with client_session(mcp._mcp_server) as client:
            result = await client.list_prompts()
            assert result.prompts is not None
            assert len(result.prompts) == 1
            prompt = result.prompts[0]
            assert prompt.name == "fn"
            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 == "optional"
            assert prompt.arguments[1].required is False

    @pytest.mark.anyio
    async def test_get_prompt(self):
        """Test getting a prompt through MCP protocol."""
        mcp = FastMCP()

        @mcp.prompt()
        def fn(name: str) -> str:
            return f"Hello, {name}!"

        async with client_session(mcp._mcp_server) as client:
            result = await client.get_prompt("fn", {"name": "World"})
            assert len(result.messages) == 1
            message = result.messages[0]
            assert message.role == "user"
            content = message.content
            assert isinstance(content, TextContent)
            assert content.text == "Hello, World!"

    @pytest.mark.anyio
    async def test_get_prompt_with_description(self):
        """Test getting a prompt through MCP protocol."""
        mcp = FastMCP()

        @mcp.prompt(description="Test prompt description")
        def fn(name: str) -> str:
            return f"Hello, {name}!"

        async with client_session(mcp._mcp_server) as client:
            result = await client.get_prompt("fn", {"name": "World"})
            assert result.description == "Test prompt description"

    @pytest.mark.anyio
    async def test_get_prompt_without_description(self):
        """Test getting a prompt without description returns empty string."""
        mcp = FastMCP()

        @mcp.prompt()
        def fn(name: str) -> str:
            return f"Hello, {name}!"

        async with client_session(mcp._mcp_server) as client:
            result = await client.get_prompt("fn", {"name": "World"})
            assert result.description == ""

    @pytest.mark.anyio
    async def test_get_prompt_with_docstring_description(self):
        """Test prompt uses docstring as description when not explicitly provided."""
        mcp = FastMCP()

        @mcp.prompt()
        def fn(name: str) -> str:
            """This is the function docstring."""
            return f"Hello, {name}!"

        async with client_session(mcp._mcp_server) as client:
            result = await client.get_prompt("fn", {"name": "World"})
            assert result.description == "This is the function docstring."

    @pytest.mark.anyio
    async def test_get_prompt_with_resource(self):
        """Test getting a prompt that returns resource content."""
        mcp = FastMCP()

        @mcp.prompt()
        def fn() -> Message:
            return UserMessage(
                content=EmbeddedResource(
                    type="resource",
                    resource=TextResourceContents(
                        uri=AnyUrl("file://file.txt"),
                        text="File contents",
                        mimeType="text/plain",
                    ),
                )
            )

        async with client_session(mcp._mcp_server) as client:
            result = await client.get_prompt("fn")
            assert len(result.messages) == 1
            message = result.messages[0]
            assert message.role == "user"
            content = message.content
            assert isinstance(content, EmbeddedResource)
            resource = content.resource
            assert isinstance(resource, TextResourceContents)
            assert resource.text == "File contents"
            assert resource.mimeType == "text/plain"

    @pytest.mark.anyio
    async def test_get_unknown_prompt(self):
        """Test error when getting unknown prompt."""
        mcp = FastMCP()
        async with client_session(mcp._mcp_server) as client:
            with pytest.raises(McpError, match="Unknown prompt"):
                await client.get_prompt("unknown")

    @pytest.mark.anyio
    async def test_get_prompt_missing_args(self):
        """Test error when required arguments are missing."""
        mcp = FastMCP()

        @mcp.prompt()
        def prompt_fn(name: str) -> str:  # pragma: no cover
            return f"Hello, {name}!"

        async with client_session(mcp._mcp_server) as client:
            with pytest.raises(McpError, match="Missing required arguments"):
                await client.get_prompt("prompt_fn")


def test_streamable_http_no_redirect() -> None:
    """Test that streamable HTTP routes are correctly configured."""
    mcp = FastMCP()
    app = mcp.streamable_http_app()

    # Find routes by type - streamable_http_app creates Route objects, not Mount objects
    streamable_routes = [
        r
        for r in app.routes
        if isinstance(r, Route) and hasattr(r, "path") and r.path == mcp.settings.streamable_http_path
    ]

    # Verify routes exist
    assert len(streamable_routes) == 1, "Should have one streamable route"

    # Verify path values
    assert streamable_routes[0].path == "/mcp", "Streamable route path should be /mcp"


def test_streamable_http_app_passes_the_configured_request_body_limit_to_its_manager() -> None:
    """SDK-defined: FastMCP forwards its public request-body setting to the Streamable HTTP manager."""
    mcp = FastMCP(max_request_body_size=8)

    mcp.streamable_http_app()

    assert mcp.session_manager.max_request_body_size == 8


@pytest.mark.anyio
async def test_sse_app_applies_the_configured_request_body_limit() -> None:
    """FastMCP forwards its request-body setting to the SSE message endpoint: larger POSTs get HTTP 413."""
    mcp = FastMCP(host="0.0.0.0", max_request_body_size=8)
    transport = httpx.ASGITransport(app=mcp.sse_app())
    async with httpx.AsyncClient(transport=transport, base_url="http://localhost") as http:
        response = await http.post(
            "/messages/?session_id=12345678123456781234567812345678",
            content=b"123456789",
            headers={"Content-Type": "application/json"},
        )
    assert response.status_code == 413