Update test typing

tests/client/test_client.py

@@ -16,7 +16,6 @@ from fastmcp.client.transports import (
     infer_transport,
 )
 from fastmcp.exceptions import ResourceError, ToolError
-from fastmcp.prompts.prompt import TextContent
 from fastmcp.server.server import FastMCP
 
 
@@ -201,8 +200,7 @@ async def test_get_prompt(fastmcp_server):
         result = await client.get_prompt("welcome", {"name": "Developer"})
 
         # The result should contain our welcome message
-        assert isinstance(result.messages[0].content, TextContent)
-        assert result.messages[0].content.text == "Welcome to FastMCP, Developer!"
+        assert result.messages[0].content.text == "Welcome to FastMCP, Developer!"  # type: ignore[attr-defined]
         assert result.description == "Example greeting prompt."
 
 
@@ -214,8 +212,7 @@ async def test_get_prompt_mcp(fastmcp_server):
         result = await client.get_prompt_mcp("welcome", {"name": "Developer"})
 
         # The result should contain our welcome message
-        assert isinstance(result.messages[0].content, TextContent)
-        assert result.messages[0].content.text == "Welcome to FastMCP, Developer!"
+        assert result.messages[0].content.text == "Welcome to FastMCP, Developer!"  # type: ignore[attr-defined]
         assert result.description == "Example greeting prompt."
 
 
@@ -522,9 +519,8 @@ class TestErrorHandling:
         async with client:
             result = await client.call_tool_mcp("error_tool", {})
             assert result.isError
-            assert isinstance(result.content[0], TextContent)
-            assert "test error" in result.content[0].text
-            assert "abc" in result.content[0].text
+            assert "test error" in result.content[0].text  # type: ignore[attr-defined]
+            assert "abc" in result.content[0].text  # type: ignore[attr-defined]
 
     async def test_general_tool_exceptions_are_masked_when_enabled(self):
         mcp = FastMCP("TestServer", mask_error_details=True)
@@ -538,9 +534,8 @@ class TestErrorHandling:
         async with client:
             result = await client.call_tool_mcp("error_tool", {})
             assert result.isError
-            assert isinstance(result.content[0], TextContent)
-            assert "test error" not in result.content[0].text
-            assert "abc" not in result.content[0].text
+            assert "test error" not in result.content[0].text  # type: ignore[attr-defined]
+            assert "abc" not in result.content[0].text  # type: ignore[attr-defined]
 
     async def test_specific_tool_errors_are_sent_to_client(self):
         mcp = FastMCP("TestServer")
@@ -554,9 +549,8 @@ class TestErrorHandling:
         async with client:
             result = await client.call_tool_mcp("custom_error_tool", {})
             assert result.isError
-            assert isinstance(result.content[0], TextContent)
-            assert "test error" in result.content[0].text
-            assert "abc" in result.content[0].text
+            assert "test error" in result.content[0].text  # type: ignore[attr-defined]
+            assert "abc" in result.content[0].text  # type: ignore[attr-defined]
 
     async def test_general_resource_exceptions_are_not_masked_by_default(self):
         mcp = FastMCP("TestServer")

tests/client/test_openapi.py

@@ -5,7 +5,6 @@ from collections.abc import Generator
 import pytest
 import uvicorn
 from fastapi import FastAPI, Request
-from mcp.types import TextContent, TextResourceContents
 
 from fastmcp import Client, FastMCP
 from fastmcp.client.transports import SSETransport, StreamableHttpTransport
@@ -111,8 +110,7 @@ class TestClientHeaders:
             transport=SSETransport(sse_server, headers={"X-TEST": "test-123"})
         ) as client:
             result = await client.read_resource("resource://get_headers_headers_get")
-            assert isinstance(result[0], TextResourceContents)
-            headers = json.loads(result[0].text)
+            headers = json.loads(result[0].text)  # type: ignore[attr-defined]
             assert headers["x-test"] == "test-123"
 
     async def test_client_headers_shttp_resource(self, shttp_server: str):
@@ -122,8 +120,7 @@ class TestClientHeaders:
             )
         ) as client:
             result = await client.read_resource("resource://get_headers_headers_get")
-            assert isinstance(result[0], TextResourceContents)
-            headers = json.loads(result[0].text)
+            headers = json.loads(result[0].text)  # type: ignore[attr-defined]
             assert headers["x-test"] == "test-123"
 
     async def test_client_headers_sse_resource_template(self, sse_server: str):
@@ -133,8 +130,7 @@ class TestClientHeaders:
             result = await client.read_resource(
                 "resource://get_header_by_name_headers/x-test"
             )
-            assert isinstance(result[0], TextResourceContents)
-            header = json.loads(result[0].text)
+            header = json.loads(result[0].text)  # type: ignore[attr-defined]
             assert header == "test-123"
 
     async def test_client_headers_shttp_resource_template(self, shttp_server: str):
@@ -146,8 +142,7 @@ class TestClientHeaders:
             result = await client.read_resource(
                 "resource://get_header_by_name_headers/x-test"
             )
-            assert isinstance(result[0], TextResourceContents)
-            header = json.loads(result[0].text)
+            header = json.loads(result[0].text)  # type: ignore[attr-defined]
             assert header == "test-123"
 
     async def test_client_headers_sse_tool(self, sse_server: str):
@@ -155,8 +150,7 @@ class TestClientHeaders:
             transport=SSETransport(sse_server, headers={"X-TEST": "test-123"})
         ) as client:
             result = await client.call_tool("post_headers_headers_post")
-            assert isinstance(result[0], TextContent)
-            headers = json.loads(result[0].text)
+            headers = json.loads(result[0].text)  # type: ignore[attr-defined]
             assert headers["x-test"] == "test-123"
 
     async def test_client_headers_shttp_tool(self, shttp_server: str):
@@ -166,8 +160,7 @@ class TestClientHeaders:
             )
         ) as client:
             result = await client.call_tool("post_headers_headers_post")
-            assert isinstance(result[0], TextContent)
-            headers = json.loads(result[0].text)
+            headers = json.loads(result[0].text)  # type: ignore[attr-defined]
             assert headers["x-test"] == "test-123"
 
     async def test_client_overrides_server_headers(self, shttp_server: str):
@@ -177,8 +170,7 @@ class TestClientHeaders:
             )
         ) as client:
             result = await client.read_resource("resource://get_headers_headers_get")
-            assert isinstance(result[0], TextResourceContents)
-            headers = json.loads(result[0].text)
+            headers = json.loads(result[0].text)  # type: ignore[attr-defined]
             assert headers["x-server-header"] == "test-client"
 
     async def test_client_with_excluded_header_is_ignored(self, sse_server: str):
@@ -193,8 +185,7 @@ class TestClientHeaders:
             )
         ) as client:
             result = await client.read_resource("resource://get_headers_headers_get")
-            assert isinstance(result[0], TextResourceContents)
-            headers = json.loads(result[0].text)
+            headers = json.loads(result[0].text)  # type: ignore[attr-defined]
             assert headers["not-host"] == "1.2.3.4"
             assert headers["host"] == "fastapi"
 
@@ -204,6 +195,5 @@ class TestClientHeaders:
         """
         async with Client(transport=StreamableHttpTransport(proxy_server)) as client:
             result = await client.read_resource("resource://get_headers_headers_get")
-            assert isinstance(result[0], TextResourceContents)
-            headers = json.loads(result[0].text)
+            headers = json.loads(result[0].text)  # type: ignore[attr-defined]
             assert headers["x-server-header"] == "test-abc"

tests/client/test_roots.py

@@ -1,7 +1,6 @@
 import json
 
 import pytest
-from mcp.types import TextContent
 
 from fastmcp import Client, Context, FastMCP
 
@@ -41,8 +40,7 @@ class TestClientRoots:
     async def test_valid_roots(self, fastmcp_server: FastMCP, roots: list[str]):
         async with Client(fastmcp_server, roots=roots) as client:
             result = await client.call_tool("list_roots", {})
-            assert isinstance(result[0], TextContent)
-            assert json.loads(result[0].text) == [
+            assert json.loads(result[0].text) == [  # type: ignore[attr-defined]
                 "file://x/y/z",
                 "file://x/y/z",
             ]

tests/client/test_sse.py

@@ -6,7 +6,6 @@ from collections.abc import Generator
 import pytest
 import uvicorn
 from mcp import McpError
-from mcp.types import TextResourceContents
 from starlette.applications import Starlette
 from starlette.routing import Mount
 
@@ -96,8 +95,7 @@ async def test_http_headers(sse_server: str):
         transport=SSETransport(sse_server, headers={"X-DEMO-HEADER": "ABC"})
     ) as client:
         raw_result = await client.read_resource("request://headers")
-        assert isinstance(raw_result[0], TextResourceContents)
-        json_result = json.loads(raw_result[0].text)
+        json_result = json.loads(raw_result[0].text)  # type: ignore[attr-defined]
         assert "x-demo-header" in json_result
         assert json_result["x-demo-header"] == "ABC"
 

tests/client/test_stdio.py

@@ -1,7 +1,6 @@
 import inspect
 
 import pytest
-from mcp.types import TextContent
 
 from fastmcp import Client
 from fastmcp.client.transports import PythonStdioTransport, StdioTransport
@@ -49,13 +48,11 @@ class TestKeepAlive:
 
         async with client:
             result1 = await client.call_tool("pid")
-            assert isinstance(result1[0], TextContent)
-            pid1 = int(result1[0].text)
+            pid1 = int(result1[0].text)  # type: ignore[attr-defined]
 
         async with client:
             result2 = await client.call_tool("pid")
-            assert isinstance(result2[0], TextContent)
-            pid2 = int(result2[0].text)
+            pid2 = int(result2[0].text)  # type: ignore[attr-defined]
 
         assert pid1 == pid2
 
@@ -69,13 +66,11 @@ class TestKeepAlive:
 
         async with client:
             result1 = await client.call_tool("pid")
-            assert isinstance(result1[0], TextContent)
-            pid1 = int(result1[0].text)
+            pid1 = int(result1[0].text)  # type: ignore[attr-defined]
 
         async with client:
             result2 = await client.call_tool("pid")
-            assert isinstance(result2[0], TextContent)
-            pid2 = int(result2[0].text)
+            pid2 = int(result2[0].text)  # type: ignore[attr-defined]
 
         assert pid1 != pid2
 
@@ -85,15 +80,13 @@ class TestKeepAlive:
 
         async with client:
             result1 = await client.call_tool("pid")
-            assert isinstance(result1[0], TextContent)
-            pid1 = int(result1[0].text)
+            pid1 = int(result1[0].text)  # type: ignore[attr-defined]
 
         await client.close()
 
         async with client:
             result2 = await client.call_tool("pid")
-            assert isinstance(result2[0], TextContent)
-            pid2 = int(result2[0].text)
+            pid2 = int(result2[0].text)  # type: ignore[attr-defined]
 
         assert pid1 != pid2
 
@@ -103,17 +96,14 @@ class TestKeepAlive:
 
         async with client:
             result1 = await client.call_tool("pid")
-            assert isinstance(result1[0], TextContent)
-            pid1 = int(result1[0].text)
+            pid1 = int(result1[0].text)  # type: ignore[attr-defined]
 
             async with client:
                 result2 = await client.call_tool("pid")
-                assert isinstance(result2[0], TextContent)
-                pid2 = int(result2[0].text)
+                pid2 = int(result2[0].text)  # type: ignore[attr-defined]
 
             result3 = await client.call_tool("pid")
-            assert isinstance(result3[0], TextContent)
-            pid3 = int(result3[0].text)
+            pid3 = int(result3[0].text)  # type: ignore[attr-defined]
 
         assert pid1 == pid2 == pid3
 

tests/client/test_streamable_http.py

@@ -6,7 +6,6 @@ from collections.abc import Generator
 import pytest
 import uvicorn
 from mcp import McpError
-from mcp.types import TextResourceContents
 from starlette.applications import Starlette
 from starlette.routing import Mount
 
@@ -106,8 +105,7 @@ async def test_http_headers(streamable_http_server: str):
         )
     ) as client:
         raw_result = await client.read_resource("request://headers")
-        assert isinstance(raw_result[0], TextResourceContents)
-        json_result = json.loads(raw_result[0].text)
+        json_result = json.loads(raw_result[0].text)  # type: ignore[attr-defined]
         assert "x-demo-header" in json_result
         assert json_result["x-demo-header"] == "ABC"
 

tests/prompts/test_prompt_manager.py

@@ -393,8 +393,7 @@ class TestContextHandling:
             messages = await prompt.render(arguments={"x": 42})
 
         assert len(messages) == 1
-        assert isinstance(messages[0].content, TextContent)
-        assert messages[0].content.text == "42"
+        assert messages[0].content.text == "42"  # type: ignore[attr-defined]
 
     async def test_context_optional(self):
         """Test that context is optional when rendering prompts."""
@@ -416,8 +415,7 @@ class TestContextHandling:
             )
 
         assert len(messages) == 1
-        assert isinstance(messages[0].content, TextContent)
-        assert messages[0].content.text == "42"
+        assert messages[0].content.text == "42"  # type: ignore[attr-defined]
 
     async def test_annotated_context_parameter_detection(self):
         """Test that annotated context parameters are properly detected in

tests/resources/test_file_resources.py

@@ -74,7 +74,6 @@ class TestFileResource:
             is_binary=True,
         )
         content = await resource.read()
-        assert isinstance(content, bytes)
         assert content == b"test content"
 
     def test_relative_path_error(self):

tests/server/http/test_http_dependencies.py

@@ -4,7 +4,6 @@ from collections.abc import Generator
 
 import pytest
 import uvicorn
-from mcp.types import TextContent, TextResourceContents
 
 from fastmcp.client import Client
 from fastmcp.client.transports import SSETransport, StreamableHttpTransport
@@ -99,8 +98,7 @@ async def test_http_headers_resource_shttp(shttp_server: str):
         )
     ) as client:
         raw_result = await client.read_resource("request://headers")
-        assert isinstance(raw_result[0], TextResourceContents)
-        json_result = json.loads(raw_result[0].text)
+        json_result = json.loads(raw_result[0].text)  # type: ignore[attr-defined]
         assert "x-demo-header" in json_result
         assert json_result["x-demo-header"] == "ABC"
 
@@ -111,8 +109,7 @@ async def test_http_headers_resource_sse(sse_server: str):
         transport=SSETransport(sse_server, headers={"X-DEMO-HEADER": "ABC"})
     ) as client:
         raw_result = await client.read_resource("request://headers")
-        assert isinstance(raw_result[0], TextResourceContents)
-        json_result = json.loads(raw_result[0].text)
+        json_result = json.loads(raw_result[0].text)  # type: ignore[attr-defined]
         assert "x-demo-header" in json_result
         assert json_result["x-demo-header"] == "ABC"
 
@@ -125,8 +122,7 @@ async def test_http_headers_tool_shttp(shttp_server: str):
         )
     ) as client:
         result = await client.call_tool("get_headers_tool")
-        assert isinstance(result[0], TextContent)
-        json_result = json.loads(result[0].text)
+        json_result = json.loads(result[0].text)  # type: ignore[attr-defined]
         assert "x-demo-header" in json_result
         assert json_result["x-demo-header"] == "ABC"
 
@@ -136,8 +132,7 @@ async def test_http_headers_tool_sse(sse_server: str):
         transport=SSETransport(sse_server, headers={"X-DEMO-HEADER": "ABC"})
     ) as client:
         result = await client.call_tool("get_headers_tool")
-        assert isinstance(result[0], TextContent)
-        json_result = json.loads(result[0].text)
+        json_result = json.loads(result[0].text)  # type: ignore[attr-defined]
         assert "x-demo-header" in json_result
         assert json_result["x-demo-header"] == "ABC"
 
@@ -150,8 +145,7 @@ async def test_http_headers_prompt_shttp(shttp_server: str):
         )
     ) as client:
         result = await client.get_prompt("get_headers_prompt")
-        assert isinstance(result.messages[0].content, TextContent)
-        json_result = json.loads(result.messages[0].content.text)
+        json_result = json.loads(result.messages[0].content.text)  # type: ignore[attr-defined]
         assert "x-demo-header" in json_result
         assert json_result["x-demo-header"] == "ABC"
 
@@ -162,7 +156,6 @@ async def test_http_headers_prompt_sse(sse_server: str):
         transport=SSETransport(sse_server, headers={"X-DEMO-HEADER": "ABC"})
     ) as client:
         result = await client.get_prompt("get_headers_prompt")
-        assert isinstance(result.messages[0].content, TextContent)
-        json_result = json.loads(result.messages[0].content.text)
+        json_result = json.loads(result.messages[0].content.text)  # type: ignore[attr-defined]
         assert "x-demo-header" in json_result
         assert json_result["x-demo-header"] == "ABC"

tests/server/openapi/test_openapi.py

@@ -9,7 +9,7 @@ from dirty_equals import IsStr
 from fastapi import FastAPI, HTTPException, Response
 from fastapi.responses import PlainTextResponse
 from httpx import ASGITransport, AsyncClient
-from mcp.types import BlobResourceContents, TextContent, TextResourceContents
+from mcp.types import BlobResourceContents
 from pydantic import BaseModel, TypeAdapter
 from pydantic.networks import AnyUrl
 
@@ -234,11 +234,7 @@ class TestTools:
                 "create_user_users_post", {"name": "David", "active": False}
             )
 
-        # Convert TextContent to dict for comparison
-        assert isinstance(tool_response, list) and len(tool_response) == 1
-        assert isinstance(tool_response[0], TextContent)
-
-        response_data = json.loads(tool_response[0].text)
+        response_data = json.loads(tool_response[0].text)  # type: ignore[attr-defined]
         expected_user = User(id=4, name="David", active=False).model_dump()
         assert response_data == expected_user
 
@@ -249,8 +245,7 @@ class TestTools:
         # Check that the user was created via MCP
         async with Client(fastmcp_openapi_server) as client:
             user_response = await client.read_resource("resource://get_user_users/4")
-            assert isinstance(user_response[0], TextResourceContents)
-            response_text = user_response[0].text
+            response_text = user_response[0].text  # type: ignore[attr-defined]
             user = json.loads(response_text)
         assert user == expected_user
 
@@ -266,11 +261,7 @@ class TestTools:
                 {"user_id": 1, "name": "XYZ"},
             )
 
-        # Convert TextContent to dict for comparison
-        assert isinstance(tool_response, list) and len(tool_response) == 1
-        assert isinstance(tool_response[0], TextContent)
-
-        response_data = json.loads(tool_response[0].text)
+        response_data = json.loads(tool_response[0].text)  # type: ignore[attr-defined]
         expected_data = dict(id=1, name="XYZ", active=True)
         assert response_data == expected_data
 
@@ -281,8 +272,7 @@ class TestTools:
         # Check that the user was updated via MCP
         async with Client(fastmcp_openapi_server) as client:
             user_response = await client.read_resource("resource://get_user_users/1")
-            assert isinstance(user_response[0], TextResourceContents)
-            response_text = user_response[0].text
+            response_text = user_response[0].text  # type: ignore[attr-defined]
             user = json.loads(response_text)
         assert user == expected_data
 
@@ -305,9 +295,7 @@ class TestTools:
         )
         async with Client(mcp_server) as client:
             tool_response = await client.call_tool("get_users_users_get", {})
-            assert isinstance(tool_response, list)
-            assert isinstance(tool_response[0], TextContent)
-            assert json.loads(tool_response[0].text) == [
+            assert json.loads(tool_response[0].text) == [  # type: ignore[attr-defined]
                 user.model_dump()
                 for user in sorted(users_db.values(), key=lambda x: x.id)
             ]
@@ -341,8 +329,7 @@ class TestResources:
             resource_response = await client.read_resource(
                 "resource://get_users_users_get"
             )
-            assert isinstance(resource_response[0], TextResourceContents)
-            response_text = resource_response[0].text
+            response_text = resource_response[0].text  # type: ignore[attr-defined]
             resource = json.loads(response_text)
         assert resource == json_users
         response = await api_client.get("/users")
@@ -369,8 +356,7 @@ class TestResources:
         """Test reading a resource that returns a string."""
         async with Client(fastmcp_openapi_server) as client:
             resource_response = await client.read_resource("resource://ping_ping_get")
-            assert isinstance(resource_response[0], TextResourceContents)
-            assert resource_response[0].text == "pong"
+            assert resource_response[0].text == "pong"  # type: ignore[attr-defined]
 
 
 class TestResourceTemplates:
@@ -407,8 +393,7 @@ class TestResourceTemplates:
             resource_response = await client.read_resource(
                 f"resource://get_user_users/{user_id}"
             )
-            assert isinstance(resource_response[0], TextResourceContents)
-            response_text = resource_response[0].text
+            response_text = resource_response[0].text  # type: ignore[attr-defined]
             resource = json.loads(response_text)
 
         assert resource == users_db[user_id].model_dump()
@@ -430,8 +415,7 @@ class TestResourceTemplates:
             resource_response = await client.read_resource(
                 f"resource://get_user_active_state_users/{is_active}/{user_id}"
             )
-            assert isinstance(resource_response[0], TextResourceContents)
-            response_text = resource_response[0].text
+            response_text = resource_response[0].text  # type: ignore[attr-defined]
             resource = json.loads(response_text)
 
         assert resource == users_db[user_id].model_dump()
@@ -681,8 +665,7 @@ class TestOpenAPI30Compatibility:
         """Test reading a resource from an OpenAPI 3.0 server."""
         async with Client(openapi_30_server) as client:
             resource_response = await client.read_resource("resource://listProducts")
-            assert isinstance(resource_response[0], TextResourceContents)
-            response_text = resource_response[0].text
+            response_text = resource_response[0].text  # type: ignore[attr-defined]
             content = json.loads(response_text)
         assert len(content) == 2
         assert content[0]["name"] == "Product 1"
@@ -692,8 +675,7 @@ class TestOpenAPI30Compatibility:
         """Test reading a resource from template from an OpenAPI 3.0 server."""
         async with Client(openapi_30_server) as client:
             resource_response = await client.read_resource("resource://getProduct/p1")
-            assert isinstance(resource_response[0], TextResourceContents)
-            response_text = resource_response[0].text
+            response_text = resource_response[0].text  # type: ignore[attr-defined]
             content = json.loads(response_text)
         assert content["id"] == "p1"
         assert content["name"] == "Product 1"
@@ -707,8 +689,7 @@ class TestOpenAPI30Compatibility:
             )
             # Result should be a text content
             assert len(result) == 1
-            assert isinstance(result[0], TextContent)
-            product = json.loads(result[0].text)
+            product = json.loads(result[0].text)  # type: ignore[attr-defined]
             assert product["id"] == "p3"
             assert product["name"] == "New Product"
             assert product["price"] == 39.99
@@ -857,8 +838,7 @@ class TestOpenAPI31Compatibility:
         """Test reading a resource from an OpenAPI 3.1 server."""
         async with Client(openapi_31_server) as client:
             resource_response = await client.read_resource("resource://listOrders")
-            assert isinstance(resource_response[0], TextResourceContents)
-            response_text = resource_response[0].text
+            response_text = resource_response[0].text  # type: ignore[attr-defined]
             content = json.loads(response_text)
         assert len(content) == 2
         assert content[0]["customer"] == "Alice"
@@ -868,8 +848,7 @@ class TestOpenAPI31Compatibility:
         """Test reading a resource from template from an OpenAPI 3.1 server."""
         async with Client(openapi_31_server) as client:
             resource_response = await client.read_resource("resource://getOrder/o1")
-            assert isinstance(resource_response[0], TextResourceContents)
-            response_text = resource_response[0].text
+            response_text = resource_response[0].text  # type: ignore[attr-defined]
             content = json.loads(response_text)
         assert content["id"] == "o1"
         assert content["customer"] == "Alice"
@@ -883,8 +862,7 @@ class TestOpenAPI31Compatibility:
             )
             # Result should be a text content
             assert len(result) == 1
-            assert isinstance(result[0], TextContent)
-            order = json.loads(result[0].text)
+            order = json.loads(result[0].text)  # type: ignore[attr-dict]
             assert order["id"] == "o3"
             assert order["customer"] == "Charlie"
             assert order["items"] == ["item4", "item5"]

tests/server/test_import_server.py

@@ -1,8 +1,6 @@
 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
 
@@ -223,8 +221,7 @@ async def test_call_imported_custom_named_tool():
 
     async with Client(main_app) as client:
         result = await client.call_tool("api_get_data", {"query": "test"})
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "Data for query: test"
+        assert result[0].text == "Data for query: test"  # type: ignore[attr-defined]
 
 
 async def test_first_level_importing_with_custom_name():
@@ -278,8 +275,7 @@ async def test_call_nested_imported_tool():
     result = await main_app._tool_manager.call_tool(
         "service_provider_compute", {"input": 21}
     )
-    assert isinstance(result[0], TextContent)
-    assert result[0].text == "42"
+    assert result[0].text == "42"  # type: ignore[attr-defined]
 
 
 async def test_import_with_proxy_tools():
@@ -302,8 +298,7 @@ async def test_import_with_proxy_tools():
     await main_app.import_server("api", proxy_app)
 
     result = await main_app._mcp_call_tool("api_get_data", {"query": "test"})
-    assert isinstance(result[0], TextContent)
-    assert result[0].text == "Data for query: test"
+    assert result[0].text == "Data for query: test"  # type: ignore[attr-defined]
 
 
 async def test_import_with_proxy_prompts():
@@ -326,7 +321,6 @@ async def test_import_with_proxy_prompts():
     await main_app.import_server("api", proxy_app)
 
     result = await main_app._mcp_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."
 
@@ -356,8 +350,7 @@ async def test_import_with_proxy_resources():
     # 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)
+        content = json.loads(result[0].text)  # type: ignore[attr-defined]
         assert content["api_key"] == "12345"
         assert content["base_url"] == "https://api.example.com"
 
@@ -387,8 +380,7 @@ async def test_import_with_proxy_resource_templates():
     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)
+        content = json.loads(result[0].text)  # type: ignore[attr-defined]
         assert content["name"] == "John Doe"
         assert content["email"] == "john@example.com"
 

tests/server/test_mount.py

@@ -3,8 +3,6 @@ import sys
 from contextlib import asynccontextmanager
 
 import pytest
-from mcp.server.lowlevel.helper_types import ReadResourceContents
-from mcp.types import TextContent, TextResourceContents
 
 from fastmcp import FastMCP
 from fastmcp.client import Client
@@ -36,8 +34,7 @@ class TestBasicMount:
 
         async with Client(main_app) as client:
             result = await client.call_tool("sub_sub_tool", {})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "This is from the sub app"
+            assert result[0].text == "This is from the sub app"  # type: ignore[attr-defined]
 
     async def test_mount_with_custom_separator(self):
         """Test mounting with a custom tool separator (deprecated but still supported)."""
@@ -57,8 +54,7 @@ class TestBasicMount:
 
         # Call the tool
         result = await main_app._mcp_call_tool("sub_greet", {"name": "World"})
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "Hello, World!"
+        assert result[0].text == "Hello, World!"  # type: ignore[attr-defined]
 
     async def test_mount_invalid_resource_prefix(self):
         main_app = FastMCP("MainApp")
@@ -147,12 +143,10 @@ class TestMultipleServerMount:
 
         # Call tools from both mounted servers
         result1 = await main_app._mcp_call_tool("weather_get_forecast", {})
-        assert isinstance(result1[0], TextContent)
-        assert result1[0].text == "Weather forecast"
+        assert result1[0].text == "Weather forecast"  # type: ignore[attr-defined]
 
         result2 = await main_app._mcp_call_tool("news_get_headlines", {})
-        assert isinstance(result2[0], TextContent)
-        assert result2[0].text == "News headlines"
+        assert result2[0].text == "News headlines"  # type: ignore[attr-defined]
 
     async def test_mount_same_prefix(self):
         """Test that mounting with the same prefix replaces the previous mount."""
@@ -227,8 +221,7 @@ class TestMultipleServerMount:
 
             # Test calling a tool
             result = await client.call_tool("working_working_tool", {})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "Working tool"
+            assert result[0].text == "Working tool"  # type: ignore[attr-defined]
 
             # Test resources
             resources = await client.list_resources()
@@ -284,8 +277,7 @@ class TestDynamicChanges:
 
         # Call the dynamically added tool
         result = await main_app._mcp_call_tool("sub_dynamic_tool", {})
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "Added after mounting"
+        assert result[0].text == "Added after mounting"  # type: ignore[attr-defined]
 
     async def test_removing_tool_after_mounting(self):
         """Test that tools removed from mounted servers are no longer accessible."""
@@ -335,8 +327,7 @@ class TestResourcesAndTemplates:
         # Check that resource can be accessed
         async with Client(main_app) as client:
             result = await client.read_resource("data://data/users")
-            assert isinstance(result[0], TextResourceContents)
-            assert json.loads(result[0].text) == ["user1", "user2"]
+            assert json.loads(result[0].text) == ["user1", "user2"]  # type: ignore[attr-defined]
 
     async def test_mount_with_resource_templates(self):
         """Test mounting a server with resource templates."""
@@ -357,8 +348,7 @@ class TestResourcesAndTemplates:
         # Check template instantiation
         async with Client(main_app) as client:
             result = await client.read_resource("users://api/123/profile")
-            assert isinstance(result[0], TextResourceContents)
-            profile = json.loads(result[0].text)
+            profile = json.loads(result[0].text)  # type: ignore
             assert profile["id"] == "123"
             assert profile["name"] == "User 123"
 
@@ -382,8 +372,7 @@ class TestResourcesAndTemplates:
         # Check access to the resource
         async with Client(main_app) as client:
             result = await client.read_resource("data://data/config")
-            assert isinstance(result[0], TextResourceContents)
-            config = json.loads(result[0].text)
+            config = json.loads(result[0].text)  # type: ignore[attr-defined]
             assert config["version"] == "1.0"
 
 
@@ -461,8 +450,7 @@ class TestProxyServer:
 
         # Call the tool
         result = await main_app._mcp_call_tool("proxy_get_data", {"query": "test"})
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "Data for test"
+        assert result[0].text == "Data for test"  # type: ignore[attr-defined]
 
     async def test_dynamically_adding_to_proxied_server(self):
         """Test that changes to the original server are reflected in the mounted proxy."""
@@ -489,8 +477,7 @@ class TestProxyServer:
 
         # Call the tool
         result = await main_app._mcp_call_tool("proxy_dynamic_data", {})
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "Dynamic data"
+        assert result[0].text == "Dynamic data"  # type: ignore[attr-defined]
 
     async def test_proxy_server_with_resources(self):
         """Test mounting a proxy server with resources."""
@@ -512,8 +499,7 @@ class TestProxyServer:
 
         # Resource should be accessible through main app
         result = await main_app._mcp_read_resource("config://proxy/settings")
-        assert isinstance(result[0], ReadResourceContents)
-        config = json.loads(result[0].content)
+        config = json.loads(result[0].content)  # type: ignore[attr-defined]
         assert config["api_key"] == "12345"
 
     async def test_proxy_server_with_prompts(self):

tests/server/test_proxy.py

@@ -1,7 +1,6 @@
 import json
 from typing import Any
 
-import mcp.types
 import pytest
 from anyio import create_task_group
 from dirty_equals import Contains
@@ -90,16 +89,14 @@ async def test_as_proxy_with_server(fastmcp_server):
     """FastMCP.as_proxy should accept a FastMCP instance."""
     proxy = FastMCP.as_proxy(fastmcp_server)
     result = await proxy._mcp_call_tool("greet", {"name": "Test"})
-    assert isinstance(result[0], mcp.types.TextContent)
-    assert result[0].text == "Hello, Test!"
+    assert result[0].text == "Hello, Test!"  # type: ignore[attr-defined]
 
 
 async def test_as_proxy_with_transport(fastmcp_server):
     """FastMCP.as_proxy should accept a ClientTransport."""
     proxy = FastMCP.as_proxy(FastMCPTransport(fastmcp_server))
     result = await proxy._mcp_call_tool("greet", {"name": "Test"})
-    assert isinstance(result[0], mcp.types.TextContent)
-    assert result[0].text == "Hello, Test!"
+    assert result[0].text == "Hello, Test!"  # type: ignore[attr-defined]
 
 
 def test_as_proxy_with_url():
@@ -138,9 +135,7 @@ class TestTools:
     async def test_call_tool_calls_tool(self, proxy_server):
         async with Client(proxy_server) as client:
             proxy_result = await client.call_tool("add", {"a": 1, "b": 2})
-
-        assert isinstance(proxy_result[0], mcp.types.TextContent)
-        assert proxy_result[0].text == "3"
+        assert proxy_result[0].text == "3"  # type: ignore[attr-defined]
 
     async def test_error_tool_raises_error(self, proxy_server):
         with pytest.raises(ToolError, match=""):
@@ -164,8 +159,7 @@ class TestResources:
     async def test_read_resource(self, proxy_server: FastMCPProxy):
         async with Client(proxy_server) as client:
             result = await client.read_resource("resource://wave")
-        assert isinstance(result[0], mcp.types.TextResourceContents)
-        assert result[0].text == "👋"
+        assert result[0].text == "👋"  # type: ignore[attr-defined]
 
     async def test_read_resource_same_as_original(self, fastmcp_server, proxy_server):
         async with Client(fastmcp_server) as client:
@@ -177,8 +171,7 @@ class TestResources:
     async def test_read_json_resource(self, proxy_server: FastMCPProxy):
         async with Client(proxy_server) as client:
             result = await client.read_resource("data://users")
-        assert isinstance(result[0], mcp.types.TextResourceContents)
-        assert json.loads(result[0].text) == USERS
+        assert json.loads(result[0].text) == USERS  # type: ignore[attr-defined]
 
     async def test_read_resource_returns_none_if_not_found(self, proxy_server):
         with pytest.raises(McpError, match="Unknown resource: resource://nonexistent"):
@@ -202,8 +195,7 @@ class TestResourceTemplates:
     async def test_read_resource_template(self, proxy_server: FastMCPProxy, id: int):
         async with Client(proxy_server) as client:
             result = await client.read_resource(f"data://user/{id}")
-        assert isinstance(result[0], mcp.types.TextResourceContents)
-        assert json.loads(result[0].text) == USERS[id - 1]
+        assert json.loads(result[0].text) == USERS[id - 1]  # type: ignore[attr-defined]
 
     async def test_read_resource_template_same_as_original(
         self, fastmcp_server, proxy_server
@@ -239,10 +231,8 @@ class TestPrompts:
     async def test_render_prompt_calls_prompt(self, proxy_server):
         async with Client(proxy_server) as client:
             result = await client.get_prompt("welcome", {"name": "Alice"})
-        assert isinstance(result.messages[0], mcp.types.PromptMessage)
         assert result.messages[0].role == "user"
-        assert isinstance(result.messages[0].content, mcp.types.TextContent)
-        assert result.messages[0].content.text == "Welcome to FastMCP, Alice!"
+        assert result.messages[0].content.text == "Welcome to FastMCP, Alice!"  # type: ignore[attr-defined]
 
 
 async def test_proxy_handles_multiple_concurrent_tasks_correctly(

tests/server/test_server.py

@@ -2,10 +2,6 @@ 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
@@ -48,8 +44,7 @@ class TestCreateServer:
             result = await client.call_tool("hello_world", {})
             assert len(result) == 1
             content = result[0]
-            assert isinstance(content, TextContent)
-            assert "¡Hola, 世界! 👋" == content.text
+            assert content.text == "¡Hola, 世界! 👋"  # type: ignore[attr-defined]
 
 
 class TestTools:
@@ -114,8 +109,7 @@ class TestToolDecorator:
             return x + y
 
         result = await mcp._mcp_call_tool("add", {"x": 1, "y": 2})
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "3"
+        assert result[0].text == "3"  # type: ignore[attr-defined]
 
     async def test_tool_decorator_incorrect_usage(self):
         mcp = FastMCP()
@@ -134,8 +128,7 @@ class TestToolDecorator:
             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"
+        assert result[0].text == "3"  # type: ignore[attr-defined]
 
     async def test_tool_decorator_with_description(self):
         mcp = FastMCP()
@@ -163,8 +156,7 @@ class TestToolDecorator:
         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"
+        assert result[0].text == "12"  # type: ignore[attr-defined]
 
     async def test_tool_decorator_classmethod(self):
         mcp = FastMCP()
@@ -178,8 +170,7 @@ class TestToolDecorator:
 
         mcp.add_tool(MyClass.add)
         result = await mcp._mcp_call_tool("add", {"y": 2})
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "12"
+        assert result[0].text == "12"  # type: ignore[attr-defined]
 
     async def test_tool_decorator_staticmethod(self):
         mcp = FastMCP()
@@ -191,8 +182,7 @@ class TestToolDecorator:
                 return x + y
 
         result = await mcp._mcp_call_tool("add", {"x": 1, "y": 2})
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "3"
+        assert result[0].text == "3"  # type: ignore[attr-defined]
 
     async def test_tool_decorator_async_function(self):
         mcp = FastMCP()
@@ -202,8 +192,7 @@ class TestToolDecorator:
             return x + y
 
         result = await mcp._mcp_call_tool("add", {"x": 1, "y": 2})
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "3"
+        assert result[0].text == "3"  # type: ignore[attr-defined]
 
     async def test_tool_decorator_classmethod_async_function(self):
         mcp = FastMCP()
@@ -217,8 +206,7 @@ class TestToolDecorator:
 
         mcp.add_tool(MyClass.add)
         result = await mcp._mcp_call_tool("add", {"y": 2})
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "12"
+        assert result[0].text == "12"  # type: ignore[attr-defined]
 
     async def test_tool_decorator_staticmethod_async_function(self):
         mcp = FastMCP()
@@ -230,8 +218,7 @@ class TestToolDecorator:
 
         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"
+        assert result[0].text == "3"  # type: ignore[attr-defined]
 
     async def test_tool_decorator_with_tags(self):
         """Test that the tool decorator properly sets tags."""
@@ -262,8 +249,7 @@ class TestToolDecorator:
 
         # 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"
+        assert result[0].text == "15"  # type: ignore[attr-defined]
 
         # Original name should not be registered
         assert "multiply" not in tools
@@ -316,8 +302,7 @@ class TestResourceDecorator:
 
         async with Client(mcp) as client:
             result = await client.read_resource("resource://data")
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Hello, world!"
+            assert result[0].text == "Hello, world!"  # type: ignore[attr-defined]
 
     async def test_resource_decorator_incorrect_usage(self):
         mcp = FastMCP()
@@ -344,8 +329,7 @@ class TestResourceDecorator:
 
         async with Client(mcp) as client:
             result = await client.read_resource("resource://data")
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Hello, world!"
+            assert result[0].text == "Hello, world!"  # type: ignore[attr-defined]
 
     async def test_resource_decorator_with_description(self):
         mcp = FastMCP()
@@ -389,8 +373,7 @@ class TestResourceDecorator:
 
         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!"
+            assert result[0].text == "My prefix: Hello, world!"  # type: ignore[attr-defined]
 
     async def test_resource_decorator_classmethod(self):
         mcp = FastMCP()
@@ -408,8 +391,7 @@ class TestResourceDecorator:
 
         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!"
+            assert result[0].text == "Class prefix: Hello, world!"  # type: ignore[attr-defined]
 
     async def test_resource_decorator_staticmethod(self):
         mcp = FastMCP()
@@ -422,8 +404,7 @@ class TestResourceDecorator:
 
         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!"
+            assert result[0].text == "Static Hello, world!"  # type: ignore[attr-defined]
 
     async def test_resource_decorator_async_function(self):
         mcp = FastMCP()
@@ -434,8 +415,7 @@ class TestResourceDecorator:
 
         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!"
+            assert result[0].text == "Async Hello, world!"  # type: ignore[attr-defined]
 
 
 class TestTemplateDecorator:
@@ -454,8 +434,7 @@ class TestTemplateDecorator:
 
         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"
+            assert result[0].text == "Data for test"  # type: ignore[attr-defined]
 
     async def test_template_decorator_incorrect_usage(self):
         mcp = FastMCP()
@@ -482,8 +461,7 @@ class TestTemplateDecorator:
 
         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"
+        assert result[0].text == "Data for test"  # type: ignore[attr-defined]
 
     async def test_template_decorator_with_description(self):
         mcp = FastMCP()
@@ -514,8 +492,7 @@ class TestTemplateDecorator:
 
         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"
+            assert result[0].text == "My prefix: Data for test"  # type: ignore[attr-defined]
 
     async def test_template_decorator_classmethod(self):
         mcp = FastMCP()
@@ -535,8 +512,7 @@ class TestTemplateDecorator:
 
         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"
+            assert result[0].text == "Class prefix: Data for test"  # type: ignore[attr-defined]
 
     async def test_template_decorator_staticmethod(self):
         mcp = FastMCP()
@@ -549,8 +525,7 @@ class TestTemplateDecorator:
 
         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"
+            assert result[0].text == "Static Data for test"  # type: ignore[attr-defined]
 
     async def test_template_decorator_async_function(self):
         mcp = FastMCP()
@@ -561,8 +536,7 @@ class TestTemplateDecorator:
 
         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"
+            assert result[0].text == "Async Data for test"  # type: ignore[attr-defined]
 
     async def test_template_decorator_with_tags(self):
         """Test that the template decorator properly sets tags."""
@@ -603,8 +577,7 @@ class TestPromptDecorator:
         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!"
+        assert content[0].content.text == "Hello, world!"  # type: ignore[attr-defined]
 
     async def test_prompt_decorator_incorrect_usage(self):
         mcp = FastMCP()
@@ -629,8 +602,7 @@ class TestPromptDecorator:
         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!"
+        assert content[0].content.text == "Hello, world!"  # type: ignore[attr-defined]
 
     async def test_prompt_decorator_with_description(self):
         mcp = FastMCP()
@@ -644,8 +616,7 @@ class TestPromptDecorator:
         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!"
+        assert content[0].content.text == "Hello, world!"  # type: ignore[attr-defined]
 
     async def test_prompt_decorator_with_parameters(self):
         mcp = FastMCP()
@@ -668,16 +639,14 @@ class TestPromptDecorator:
             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!"
+            assert message.content.text == "Hello, World!"  # type: ignore[attr-defined]
 
             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!"
+            assert message.content.text == "Hi, World!"  # type: ignore[attr-defined]
 
     async def test_prompt_decorator_instance_method(self):
         mcp = FastMCP()
@@ -696,8 +665,7 @@ class TestPromptDecorator:
             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!"
+            assert message.content.text == "My prefix: Hello, world!"  # type: ignore[attr-defined]
 
     async def test_prompt_decorator_classmethod(self):
         mcp = FastMCP()
@@ -715,8 +683,7 @@ class TestPromptDecorator:
             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!"
+            assert message.content.text == "Class prefix: Hello, world!"  # type: ignore[attr-defined]
 
     async def test_prompt_decorator_staticmethod(self):
         mcp = FastMCP()
@@ -731,8 +698,7 @@ class TestPromptDecorator:
             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!"
+            assert message.content.text == "Static Hello, world!"  # type: ignore[attr-defined]
 
     async def test_prompt_decorator_async_function(self):
         mcp = FastMCP()
@@ -745,8 +711,7 @@ class TestPromptDecorator:
             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!"
+            assert message.content.text == "Async Hello, world!"  # type: ignore[attr-defined]
 
     async def test_prompt_decorator_with_tags(self):
         """Test that the prompt decorator properly sets tags."""
@@ -943,20 +908,17 @@ class TestResourcePrefixMounting:
         async with Client(main_server) as client:
             # Regular resource
             result = await client.read_resource("resource://prefix/test-resource")
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Resource content"
+            assert result[0].text == "Resource content"  # type: ignore[attr-defined]
 
             # Absolute path resource
             result = await client.read_resource("resource://prefix//absolute/path")
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Absolute resource content"
+            assert result[0].text == "Absolute resource content"  # type: ignore[attr-defined]
 
             # Template resource
             result = await client.read_resource(
                 "resource://prefix/param-value/template"
             )
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Template resource with param-value"
+            assert result[0].text == "Template resource with param-value"  # type: ignore[attr-defined]
 
     @pytest.mark.parametrize(
         "uri,prefix,expected_match,expected_strip",
@@ -1032,15 +994,12 @@ class TestResourcePrefixMounting:
         # 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"
+            assert result[0].text == "Resource content"  # type: ignore[attr-defined]
 
             result = await client.read_resource("resource://imported//absolute/path")
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Absolute resource content"
+            assert result[0].text == "Absolute resource content"  # type: ignore[attr-defined]
 
             result = await client.read_resource(
                 "resource://imported/param-value/template"
             )
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Template resource with param-value"
+            assert result[0].text == "Template resource with param-value"  # type: ignore[attr-defined]

tests/server/test_server_interactions.py

@@ -10,7 +10,6 @@ import pydantic_core
 import pytest
 from mcp import McpError
 from mcp.types import (
-    BlobResourceContents,
     ImageContent,
     TextContent,
     TextResourceContents,
@@ -77,14 +76,12 @@ class TestTools:
     async def test_call_tool(self, tool_server: FastMCP):
         async with Client(tool_server) as client:
             result = await client.call_tool("add", {"x": 1, "y": 2})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "3"
+            assert result[0].text == "3"  # type: ignore[attr-defined]
 
     async def test_call_tool_as_client(self, tool_server: FastMCP):
         async with Client(tool_server) as client:
             result = await client.call_tool("add", {"x": 1, "y": 2})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "3"
+            assert result[0].text == "3"  # type: ignore[attr-defined]
 
     async def test_call_tool_error(self, tool_server: FastMCP):
         async with Client(tool_server) as client:
@@ -113,8 +110,7 @@ class TestTools:
     async def test_tool_returns_list(self, tool_server: FastMCP):
         async with Client(tool_server) as client:
             result = await client.call_tool("list_tool", {})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == '[\n  "x",\n  2\n]'
+            assert result[0].text == '[\n  "x",\n  2\n]'  # type: ignore[attr-defined]
 
 
 class TestToolReturnTypes:
@@ -127,8 +123,7 @@ class TestToolReturnTypes:
 
         async with Client(mcp) as client:
             result = await client.call_tool("string_tool", {})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "Hello, world!"
+            assert result[0].text == "Hello, world!"  # type: ignore[attr-defined]
 
     async def test_bytes(self, tmp_path: Path):
         mcp = FastMCP()
@@ -139,8 +134,7 @@ class TestToolReturnTypes:
 
         async with Client(mcp) as client:
             result = await client.call_tool("bytes_tool", {})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == '"Hello, world!"'
+            assert result[0].text == '"Hello, world!"'  # type: ignore[attr-defined]
 
     async def test_uuid(self):
         mcp = FastMCP()
@@ -153,8 +147,7 @@ class TestToolReturnTypes:
 
         async with Client(mcp) as client:
             result = await client.call_tool("uuid_tool", {})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == pydantic_core.to_json(test_uuid).decode()
+            assert result[0].text == pydantic_core.to_json(test_uuid).decode()  # type: ignore[attr-defined]
 
     async def test_path(self):
         mcp = FastMCP()
@@ -167,8 +160,7 @@ class TestToolReturnTypes:
 
         async with Client(mcp) as client:
             result = await client.call_tool("path_tool", {})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == pydantic_core.to_json(test_path).decode()
+            assert result[0].text == pydantic_core.to_json(test_path).decode()  # type: ignore[attr-defined]
 
     async def test_datetime(self):
         mcp = FastMCP()
@@ -181,8 +173,7 @@ class TestToolReturnTypes:
 
         async with Client(mcp) as client:
             result = await client.call_tool("datetime_tool", {})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == pydantic_core.to_json(dt).decode()
+            assert result[0].text == pydantic_core.to_json(dt).decode()  # type: ignore[attr-defined]
 
     async def test_image(self, tmp_path: Path):
         mcp = FastMCP()
@@ -337,8 +328,7 @@ class TestToolParameters:
         async with Client(mcp) as client:
             # String with integer value should be coerced to int
             result = await client.call_tool("add_one", {"x": "42"})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "43"
+            assert result[0].text == "43"  # type: ignore[attr-defined]
 
     async def test_tool_bool_coercion(self):
         """Test string-to-bool type coercion."""
@@ -351,12 +341,10 @@ class TestToolParameters:
         async with Client(mcp) as client:
             # String with boolean value should be coerced to bool
             result = await client.call_tool("toggle", {"flag": "true"})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "false"
+            assert result[0].text == "false"  # type: ignore[attr-defined]
 
             result = await client.call_tool("toggle", {"flag": "false"})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "true"
+            assert result[0].text == "true"  # type: ignore[attr-defined]
 
     async def test_annotated_field_validation(self):
         mcp = FastMCP()
@@ -411,8 +399,7 @@ class TestToolParameters:
 
         async with Client(mcp) as client:
             result = await client.call_tool("analyze", {"x": "a"})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "a"
+            assert result[0].text == "a"  # type: ignore[attr-defined]
 
     async def test_enum_type_validation_error(self):
         mcp = FastMCP()
@@ -444,8 +431,7 @@ class TestToolParameters:
 
         async with Client(mcp) as client:
             result = await client.call_tool("analyze", {"x": "red"})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "red"
+            assert result[0].text == "red"  # type: ignore[attr-defined]
 
     async def test_union_type_validation(self):
         mcp = FastMCP()
@@ -456,12 +442,10 @@ class TestToolParameters:
 
         async with Client(mcp) as client:
             result = await client.call_tool("analyze", {"x": 1})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "1"
+            assert result[0].text == "1"  # type: ignore[attr-defined]
 
             result = await client.call_tool("analyze", {"x": 1.0})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "1.0"
+            assert result[0].text == "1.0"  # type: ignore[attr-defined]
 
             with pytest.raises(ToolError, match="Error calling tool 'analyze'"):
                 await client.call_tool("analyze", {"x": "not a number"})
@@ -479,8 +463,7 @@ class TestToolParameters:
 
         async with Client(mcp) as client:
             result = await client.call_tool("send_path", {"path": str(test_path)})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == str(test_path)
+            assert result[0].text == str(test_path)  # type: ignore[attr-defined]
 
     async def test_path_type_error(self):
         mcp = FastMCP()
@@ -505,8 +488,7 @@ class TestToolParameters:
 
         async with Client(mcp) as client:
             result = await client.call_tool("send_uuid", {"x": test_uuid})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == str(test_uuid)
+            assert result[0].text == str(test_uuid)  # type: ignore[attr-defined]
 
     async def test_uuid_type_error(self):
         mcp = FastMCP()
@@ -530,8 +512,7 @@ class TestToolParameters:
 
         async with Client(mcp) as client:
             result = await client.call_tool("send_datetime", {"x": dt})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == dt.isoformat()
+            assert result[0].text == dt.isoformat()  # type: ignore[attr-defined]
 
     async def test_datetime_type_parse_string(self):
         mcp = FastMCP()
@@ -544,8 +525,7 @@ class TestToolParameters:
             result = await client.call_tool(
                 "send_datetime", {"x": "2021-01-01T00:00:00"}
             )
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "2021-01-01T00:00:00"
+            assert result[0].text == "2021-01-01T00:00:00"  # type: ignore[attr-defined]
 
     async def test_datetime_type_error(self):
         mcp = FastMCP()
@@ -567,8 +547,7 @@ class TestToolParameters:
 
         async with Client(mcp) as client:
             result = await client.call_tool("send_date", {"x": datetime.date.today()})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == datetime.date.today().isoformat()
+            assert result[0].text == datetime.date.today().isoformat()  # type: ignore[attr-defined]
 
     async def test_date_type_parse_string(self):
         mcp = FastMCP()
@@ -579,8 +558,7 @@ class TestToolParameters:
 
         async with Client(mcp) as client:
             result = await client.call_tool("send_date", {"x": "2021-01-01"})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "2021-01-01"
+            assert result[0].text == "2021-01-01"  # type: ignore[attr-defined]
 
     async def test_timedelta_type(self):
         mcp = FastMCP()
@@ -593,8 +571,7 @@ class TestToolParameters:
             result = await client.call_tool(
                 "send_timedelta", {"x": datetime.timedelta(days=1)}
             )
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "1 day, 0:00:00"
+            assert result[0].text == "1 day, 0:00:00"  # type: ignore[attr-defined]
 
     async def test_timedelta_type_parse_int(self):
         mcp = FastMCP()
@@ -605,8 +582,7 @@ class TestToolParameters:
 
         async with Client(mcp) as client:
             result = await client.call_tool("send_timedelta", {"x": 1000})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "0:16:40"
+            assert result[0].text == "0:16:40"  # type: ignore[attr-defined]
 
 
 class TestToolContextInjection:
@@ -639,7 +615,7 @@ class TestToolContextInjection:
             result = await client.call_tool("tool_with_context", {"x": 42})
             assert len(result) == 1
             content = result[0]
-            assert isinstance(content, TextContent)
+            assert content.text == "2"  # type: ignore[attr-defined]
 
     async def test_async_context(self):
         """Test that context works in async functions."""
@@ -654,8 +630,7 @@ class TestToolContextInjection:
             result = await client.call_tool("async_tool", {"x": 42})
             assert len(result) == 1
             content = result[0]
-            assert isinstance(content, TextContent)
-            assert content.text == "Async request 2: 42"
+            assert content.text == "Async request 2: 42"  # type: ignore[attr-defined]
 
     async def test_optional_context(self):
         """Test that context is optional."""
@@ -669,8 +644,7 @@ class TestToolContextInjection:
             result = await client.call_tool("no_context", {"x": 21})
             assert len(result) == 1
             content = result[0]
-            assert isinstance(content, TextContent)
-            assert content.text == "42"
+            assert content.text == "42"  # type: ignore[attr-defined]
 
     async def test_context_resource_access(self):
         """Test that context can access resources."""
@@ -692,8 +666,7 @@ class TestToolContextInjection:
             result = await client.call_tool("tool_with_resource", {})
             assert len(result) == 1
             content = result[0]
-            assert isinstance(content, TextContent)
-            assert "Read resource: resource data" in content.text
+            assert "Read resource: resource data" in content.text  # type: ignore[attr-defined]
 
     async def test_tool_decorator_with_tags(self):
         """Test that the tool decorator properly sets tags."""
@@ -721,8 +694,7 @@ class TestToolContextInjection:
 
         async with Client(mcp) as client:
             result = await client.call_tool("MyTool", {"x": 2})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "4"
+            assert result[0].text == "4"  # type: ignore[attr-defined]
 
 
 class TestResource:
@@ -739,8 +711,7 @@ class TestResource:
 
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("resource://test"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Hello, world!"
+            assert result[0].text == "Hello, world!"  # type: ignore[attr-defined]
 
     async def test_binary_resource(self):
         mcp = FastMCP()
@@ -758,8 +729,7 @@ class TestResource:
 
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("resource://binary"))
-            assert isinstance(result[0], BlobResourceContents)
-            assert result[0].blob == base64.b64encode(b"Binary data").decode()
+            assert result[0].blob == base64.b64encode(b"Binary data").decode()  # type: ignore[attr-defined]
 
     async def test_file_resource_text(self, tmp_path: Path):
         mcp = FastMCP()
@@ -775,8 +745,7 @@ class TestResource:
 
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("file://test.txt"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Hello from file!"
+            assert result[0].text == "Hello from file!"  # type: ignore[attr-defined]
 
     async def test_file_resource_binary(self, tmp_path: Path):
         mcp = FastMCP()
@@ -795,8 +764,7 @@ class TestResource:
 
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("file://test.bin"))
-            assert isinstance(result[0], BlobResourceContents)
-            assert result[0].blob == base64.b64encode(b"Binary file data").decode()
+            assert result[0].blob == base64.b64encode(b"Binary file data").decode()  # type: ignore[attr-defined]
 
 
 class TestResourceContext:
@@ -810,8 +778,7 @@ class TestResourceContext:
 
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("resource://test"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "2"
+            assert result[0].text == "2"  # type: ignore[attr-defined]
 
 
 class TestResourceTemplates:
@@ -860,8 +827,7 @@ class TestResourceTemplates:
 
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("resource://test/data"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Data for test"
+            assert result[0].text == "Data for test"  # type: ignore[attr-defined]
 
     async def test_resource_mismatched_params(self):
         """Test that mismatched parameters raise an error"""
@@ -888,8 +854,7 @@ class TestResourceTemplates:
             result = await client.read_resource(
                 AnyUrl("resource://cursor/fastmcp/data")
             )
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Data for cursor/fastmcp"
+            assert result[0].text == "Data for cursor/fastmcp"  # type: ignore[attr-defined]
 
     async def test_resource_multiple_mismatched_params(self):
         """Test that mismatched parameters raise an error"""
@@ -913,8 +878,7 @@ class TestResourceTemplates:
 
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("resource://static"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Static data"
+            assert result[0].text == "Static data"  # type: ignore[attr-defined]
 
     async def test_template_with_varkwargs(self):
         """Test that a template can have **kwargs."""
@@ -926,8 +890,7 @@ class TestResourceTemplates:
 
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("test://1/2/3"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "6"
+            assert result[0].text == "6"  # type: ignore[attr-defined]
 
     async def test_template_with_default_params(self):
         """Test that a template can have default parameters."""
@@ -946,13 +909,11 @@ class TestResourceTemplates:
         # Call the template and verify it uses the default value
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("math://add/5"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "15"  # 5 + default 10
+            assert result[0].text == "15"  # type: ignore[attr-defined]
 
             # Can also call with explicit params
             result2 = await client.read_resource(AnyUrl("math://add/7"))
-            assert isinstance(result2[0], TextResourceContents)
-            assert result2[0].text == "17"  # 7 + default 10
+            assert result2[0].text == "17"  # type: ignore[attr-defined]
 
     async def test_template_to_resource_conversion(self):
         """Test that a template can be converted to a resource."""
@@ -971,8 +932,7 @@ class TestResourceTemplates:
         # When accessed, should create a concrete resource
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("resource://test/data"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Data for test"
+            assert result[0].text == "Data for test"  # type: ignore[attr-defined]
 
     async def test_stacked_resource_template_decorators(self):
         """Test that resource template decorators can be stacked."""
@@ -1011,15 +971,15 @@ class TestResourceTemplates:
             email_result = await client.read_resource(
                 AnyUrl("users://email/user@example.com")
             )
-            assert isinstance(email_result[0], TextResourceContents)
-            email_data = json.loads(email_result[0].text)
+            assert email_result[0].text  # type: ignore[attr-defined]
+            email_data = json.loads(email_result[0].text)  # type: ignore[attr-defined]
             assert email_data["lookup"] == "email"
             assert email_data["email"] == "user@example.com"
 
             # Test lookup by name
             name_result = await client.read_resource(AnyUrl("users://name/John"))
-            assert isinstance(name_result[0], TextResourceContents)
-            name_data = json.loads(name_result[0].text)
+            assert name_result[0].text  # type: ignore[attr-defined]
+            name_
             assert name_data["lookup"] == "name"
             assert name_data["name"] == "John"
             assert name_data["email"] == "dummy@example.com"
@@ -1044,8 +1004,7 @@ class TestResourceTemplates:
 
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("resource://test/data"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Template resource: test/data"
+            assert result[0].text == "Template resource: test/data"  # type: ignore[attr-defined]
 
     async def test_templates_match_in_order_of_definition(self):
         """
@@ -1065,12 +1024,10 @@ class TestResourceTemplates:
 
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("resource://a/b/c"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Template resource 1: a/b/c"
+            assert result[0].text == "Template resource 1: a/b/c"  # type: ignore[attr-defined]
 
             result = await client.read_resource(AnyUrl("resource://a/b"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Template resource 1: a/b"
+            assert result[0].text == "Template resource 1: a/b"  # type: ignore[attr-defined]
 
     async def test_templates_shadow_each_other_reorder(self):
         """
@@ -1089,12 +1046,10 @@ class TestResourceTemplates:
 
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("resource://a/b/c"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Template resource 2: a/b/c"
+            assert result[0].text == "Template resource 2: a/b/c"  # type: ignore[attr-defined]
 
             result = await client.read_resource(AnyUrl("resource://a/b"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text == "Template resource 1: a/b"
+            assert result[0].text == "Template resource 1: a/b"  # type: ignore[attr-defined]
 
 
 class TestResourceTemplateContext:
@@ -1108,8 +1063,7 @@ class TestResourceTemplateContext:
 
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("resource://test"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text.startswith("Resource template: test 2")
+            assert result[0].text.startswith("Resource template: test 2")  # type: ignore[attr-defined]
 
     async def test_resource_template_context_with_callable_object(self):
         mcp = FastMCP()
@@ -1122,8 +1076,7 @@ class TestResourceTemplateContext:
 
         async with Client(mcp) as client:
             result = await client.read_resource(AnyUrl("resource://test"))
-            assert isinstance(result[0], TextResourceContents)
-            assert result[0].text.startswith("Resource template: test 2")
+            assert result[0].text.startswith("Resource template: test 2")  # type: ignore[attr-defined]
 
 
 class TestPrompts:
@@ -1143,8 +1096,7 @@ class TestPrompts:
         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!"
+        assert content[0].content.text == "Hello, world!"  # type: ignore[attr-defined]
 
     async def test_prompt_decorator_with_name(self):
         """Test prompt decorator with custom name."""
@@ -1159,8 +1111,7 @@ class TestPrompts:
         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!"
+        assert content[0].content.text == "Hello, world!"  # type: ignore[attr-defined]
 
     async def test_prompt_decorator_with_description(self):
         """Test prompt decorator with custom description."""
@@ -1175,8 +1126,7 @@ class TestPrompts:
         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!"
+        assert content[0].content.text == "Hello, world!"  # type: ignore[attr-defined]
 
     def test_prompt_decorator_error(self):
         """Test error when decorator is used incorrectly."""
@@ -1224,8 +1174,7 @@ class TestPrompts:
             message = result.messages[0]
             assert message.role == "user"
             content = message.content
-            assert isinstance(content, TextContent)
-            assert content.text == "Hello, World!"
+            assert content.text == "Hello, World!"  # type: ignore[attr-defined]
 
     async def test_get_prompt_with_resource(self):
         """Test getting a prompt that returns resource content."""
@@ -1249,10 +1198,10 @@ class TestPrompts:
             result = await client.get_prompt("fn")
             assert result.messages[0].role == "user"
             content = result.messages[0].content
-            assert isinstance(content, EmbeddedResource)
+            assert isinstance(content, EmbeddedResource)  # type: ignore[attr-defined]
             resource = content.resource
-            assert isinstance(resource, TextResourceContents)
-            assert resource.text == "File contents"
+            assert isinstance(resource, TextResourceContents)  # type: ignore[attr-defined]
+            assert resource.text == "File contents"  # type: ignore[attr-defined]
             assert resource.mimeType == "text/plain"
 
     async def test_get_unknown_prompt(self):
@@ -1342,5 +1291,4 @@ class TestPromptContext:
             assert len(result.messages) == 1
             message = result.messages[0]
             assert message.role == "user"
-            assert isinstance(message.content, TextContent)
-            assert message.content.text == "Hello, World! 2"
+            assert message.content.text == "Hello, World! 2"  # type: ignore[attr-defined]

tests/server/test_tool_annotations.py

@@ -1,6 +1,6 @@
 from typing import Any
 
-from mcp.types import TextContent, ToolAnnotations
+from mcp.types import ToolAnnotations
 
 from fastmcp import Client, FastMCP
 
@@ -212,8 +212,7 @@ async def test_tool_functionality_with_annotations():
             "create_item", {"name": "test_item", "value": 42}
         )
         assert len(result) == 1
-        assert isinstance(result[0], TextContent)
 
         # The result should contain the expected JSON
-        assert '"name": "test_item"' in result[0].text
-        assert '"value": 42' in result[0].text
+        assert '"name": "test_item"' in result[0].text  # type: ignore[attr-defined]
+        assert '"value": 42' in result[0].text  # type: ignore[attr-defined]

tests/test_examples.py

@@ -1,10 +1,5 @@
 """Tests for example servers"""
 
-from mcp.types import (
-    PromptMessage,
-    TextContent,
-    TextResourceContents,
-)
 from pydantic import AnyUrl
 
 from fastmcp import Client
@@ -17,8 +12,7 @@ async def test_simple_echo():
     async with Client(mcp) as client:
         result = await client.call_tool("echo", {"text": "hello"})
         assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "hello"
+        assert result[0].text == "hello"  # type: ignore[attr-defined]
 
 
 async def test_complex_inputs():
@@ -31,8 +25,7 @@ async def test_complex_inputs():
             "name_shrimp", {"tank": tank, "extra_names": ["charlie"]}
         )
         assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == '[\n  "bob",\n  "alice",\n  "charlie"\n]'
+        assert result[0].text == '[\n  "bob",\n  "alice",\n  "charlie"\n]'  # type: ignore[attr-defined]
 
 
 async def test_desktop(monkeypatch):
@@ -43,15 +36,12 @@ async def test_desktop(monkeypatch):
         # Test the add function
         result = await client.call_tool("add", {"a": 1, "b": 2})
         assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "3"
+        assert result[0].text == "3"  # type: ignore[attr-defined]
 
     async with Client(mcp) as client:
         result = await client.read_resource(AnyUrl("greeting://rooter12"))
         assert len(result) == 1
-        assert isinstance(result[0], TextResourceContents)
-        assert isinstance(result[0].text, str)
-        assert result[0].text == "Hello, rooter12!"
+        assert result[0].text == "Hello, rooter12!"  # type: ignore[attr-defined]
 
 
 async def test_echo():
@@ -61,27 +51,19 @@ async def test_echo():
     async with Client(mcp) as client:
         result = await client.call_tool("echo_tool", {"text": "hello"})
         assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "hello"
+        assert result[0].text == "hello"  # type: ignore[attr-defined]
 
     async with Client(mcp) as client:
         result = await client.read_resource(AnyUrl("echo://static"))
         assert len(result) == 1
-        assert isinstance(result[0], TextResourceContents)
-        assert isinstance(result[0].text, str)
-        assert result[0].text == "Echo!"
+        assert result[0].text == "Echo!"  # type: ignore[attr-defined]
 
     async with Client(mcp) as client:
         result = await client.read_resource(AnyUrl("echo://server42"))
         assert len(result) == 1
-        assert isinstance(result[0], TextResourceContents)
-        assert isinstance(result[0].text, str)
-        assert result[0].text == "Echo: server42"
+        assert result[0].text == "Echo: server42"  # type: ignore[attr-defined]
 
     async with Client(mcp) as client:
         result = await client.get_prompt("echo", {"text": "hello"})
         assert len(result.messages) == 1
-        assert isinstance(result.messages[0], PromptMessage)
-        assert isinstance(result.messages[0].content, TextContent)
-        assert isinstance(result.messages[0].content.text, str)
-        assert result.messages[0].content.text == "hello"
+        assert result.messages[0].content.text == "hello"  # type: ignore[attr-defined]

tests/tools/test_tool.py

@@ -1,5 +1,5 @@
 import pytest
-from mcp.types import ImageContent, TextContent
+from mcp.types import ImageContent
 from pydantic import BaseModel
 
 from fastmcp import FastMCP, Image
@@ -209,9 +209,7 @@ class TestLegacyToolJsonParsing:
 
         # Run the tool which will do JSON parsing
         result = await tool.run(json_args)
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "1-a,b,c"
+        assert result[0].text == "1-a,b,c"  # type: ignore[attr-dict]
 
     async def test_str_vs_list_str(self):
         """Test handling of string vs list[str] type annotations."""
@@ -223,23 +221,17 @@ class TestLegacyToolJsonParsing:
 
         # Test regular string input (should remain a string)
         result = await tool.run({"str_or_list": "hello"})
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "hello"
+        assert result[0].text == "hello"  # type: ignore[attr-dict]
 
         # Test JSON string input (should be parsed as a string)
         result = await tool.run({"str_or_list": '"hello"'})
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "hello"
+        assert result[0].text == "hello"  # type: ignore[attr-dict]
 
         # Test JSON list input (should be parsed as a list)
         result = await tool.run({"str_or_list": '["hello", "world"]'})
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
 
         # The exact formatting might vary, so we just check that it contains the key elements
-        text_without_whitespace = result[0].text.replace(" ", "").replace("\n", "")
+        text_without_whitespace = result[0].text.replace(" ", "").replace("\n", "")  # type: ignore[attr-dict]
         assert "hello" in text_without_whitespace
         assert "world" in text_without_whitespace
         assert "[" in text_without_whitespace
@@ -256,9 +248,7 @@ class TestLegacyToolJsonParsing:
         # Invalid JSON should remain a string
         invalid_json = "{'nice to meet you': 'hello', 'goodbye': 5}"
         result = await tool.run({"string": invalid_json})
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == invalid_json
+        assert result[0].text == invalid_json  # type: ignore[attr-dict]
 
     async def test_keep_str_union_as_str(self):
         """Test that string arguments are kept as strings when parsing would create an invalid value"""
@@ -273,9 +263,7 @@ class TestLegacyToolJsonParsing:
         # Invalid JSON for the union type should remain a string
         invalid_json = "{'nice to meet you': 'hello', 'goodbye': 5}"
         result = await tool.run({"string": invalid_json})
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == invalid_json
+        assert result[0].text == invalid_json  # type: ignore[attr-dict]
 
     async def test_complex_type_validation(self):
         """Test that parsed JSON is validated against complex types"""
@@ -292,11 +280,9 @@ class TestLegacyToolJsonParsing:
         # Valid JSON for the model
         valid_json = '{"x": 1, "y": {"1": "hello"}}'
         result = await tool.run({"data": valid_json})
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert '"x": 1' in result[0].text
-        assert '"y": {' in result[0].text
-        assert '"1": "hello"' in result[0].text
+        assert '"x": 1' in result[0].text  # type: ignore[attr-dict]
+        assert '"y": {' in result[0].text  # type: ignore[attr-dict]
+        assert '"1": "hello"' in result[0].text  # type: ignore[attr-dict]
 
         # Invalid JSON for the model (y has string keys, not int keys)
         # Should throw a validation error
@@ -317,8 +303,7 @@ class TestLegacyToolJsonParsing:
             result = await client.call_tool(
                 "process_list", {"items": "[1, 2, 3, 4, 5]"}
             )
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "15"
+            assert result[0].text == "15"  # type: ignore[attr-dict]
 
     async def test_tool_list_coercion_error(self):
         """Test that a list coercion error is raised if the input is not a valid list."""
@@ -348,8 +333,7 @@ class TestLegacyToolJsonParsing:
             result = await client.call_tool(
                 "process_dict", {"data": '{"a": 1, "b": "2", "c": 3}'}
             )
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "6"
+            assert result[0].text == "6"  # type: ignore[attr-dict]
 
     async def test_tool_set_coercion(self):
         """Test JSON string to set type coercion."""
@@ -362,8 +346,7 @@ class TestLegacyToolJsonParsing:
 
         async with Client(mcp) as client:
             result = await client.call_tool("process_set", {"items": "[1, 2, 3, 4, 5]"})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "15"
+            assert result[0].text == "15"  # type: ignore[attr-dict]
 
     async def test_tool_tuple_coercion(self):
         """Test JSON string to tuple type coercion."""
@@ -376,5 +359,4 @@ class TestLegacyToolJsonParsing:
 
         async with Client(mcp) as client:
             result = await client.call_tool("process_tuple", {"items": '["1", "two"]'})
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "4"
+            assert result[0].text == "4"  # type: ignore[attr-dict]

tests/tools/test_tool_manager.py

@@ -5,7 +5,7 @@ from typing import Annotated, Any
 
 import pydantic_core
 import pytest
-from mcp.types import ImageContent, TextContent
+from mcp.types import ImageContent
 from pydantic import BaseModel
 
 from fastmcp import Context, FastMCP, Image
@@ -318,13 +318,8 @@ class TestCallTools:
         manager = ToolManager()
         manager.add_tool_from_fn(add)
         result = await manager.call_tool("add", {"a": 1, "b": 2})
-        assert isinstance(result, list)
-        assert len(result) == 1
-        from mcp.types import TextContent
 
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "3"
-        assert json.loads(result[0].text) == 3
+        assert result[0].text == "3"  # type: ignore[attr-defined]
 
     async def test_call_async_tool(self):
         async def double(n: int) -> int:
@@ -334,12 +329,7 @@ class TestCallTools:
         manager = ToolManager()
         manager.add_tool_from_fn(double)
         result = await manager.call_tool("double", {"n": 5})
-        assert isinstance(result, list)
-        assert len(result) == 1
-
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "10"
-        assert json.loads(result[0].text) == 10
+        assert result[0].text == "10"  # type: ignore[attr-defined]
 
     async def test_call_tool_callable_object(self):
         class Adder:
@@ -352,11 +342,7 @@ class TestCallTools:
         manager = ToolManager()
         manager.add_tool_from_fn(Adder())
         result = await manager.call_tool("Adder", {"x": 1, "y": 2})
-        assert isinstance(result, list)
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "3"
-        assert json.loads(result[0].text) == 3
+        assert result[0].text == "3"  # type: ignore[attr-defined]
 
     async def test_call_tool_callable_object_async(self):
         class Adder:
@@ -369,11 +355,7 @@ class TestCallTools:
         manager = ToolManager()
         manager.add_tool_from_fn(Adder())
         result = await manager.call_tool("Adder", {"x": 1, "y": 2})
-        assert isinstance(result, list)
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "3"
-        assert json.loads(result[0].text) == 3
+        assert result[0].text == "3"  # type: ignore[attr-defined]
 
     async def test_call_tool_with_default_args(self):
         def add(a: int, b: int = 1) -> int:
@@ -383,12 +365,8 @@ class TestCallTools:
         manager = ToolManager()
         manager.add_tool_from_fn(add)
         result = await manager.call_tool("add", {"a": 1})
-        assert isinstance(result, list)
-        assert len(result) == 1
 
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "2"
-        assert json.loads(result[0].text) == 2
+        assert result[0].text == "2"  # type: ignore[attr-defined]
 
     async def test_call_tool_with_missing_args(self):
         def add(a: int, b: int) -> int:
@@ -413,11 +391,7 @@ class TestCallTools:
         manager.add_tool_from_fn(sum_vals)
 
         result = await manager.call_tool("sum_vals", {"vals": [1, 2, 3]})
-        assert isinstance(result, list)
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "6"
-        assert json.loads(result[0].text) == 6
+        assert result[0].text == "6"  # type: ignore[attr-defined]
 
     async def test_call_tool_with_list_int_input_legacy_behavior(self):
         """Legacy behavior -- parse a stringified JSON object"""
@@ -431,11 +405,7 @@ class TestCallTools:
 
         with temporary_settings(tool_attempt_parse_json_args=True):
             result = await manager.call_tool("sum_vals", {"vals": "[1, 2, 3]"})
-            assert isinstance(result, list)
-            assert len(result) == 1
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "6"
-            assert json.loads(result[0].text) == 6
+            assert result[0].text == "6"  # type: ignore[attr-defined]
 
     async def test_call_tool_with_list_str_or_str_input(self):
         def concat_strs(vals: list[str] | str) -> str:
@@ -446,16 +416,10 @@ class TestCallTools:
 
         # Try both with plain python object and with JSON list
         result = await manager.call_tool("concat_strs", {"vals": ["a", "b", "c"]})
-        assert isinstance(result, list)
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "abc"
+        assert result[0].text == "abc"  # type: ignore[attr-defined]
 
         result = await manager.call_tool("concat_strs", {"vals": "a"})
-        assert isinstance(result, list)
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "a"
+        assert result[0].text == "a"  # type: ignore[attr-defined]
 
     async def test_call_tool_with_list_str_or_str_input_legacy_behavior(self):
         """Legacy behavior -- parse a stringified JSON object"""
@@ -468,16 +432,10 @@ class TestCallTools:
 
         with temporary_settings(tool_attempt_parse_json_args=True):
             result = await manager.call_tool("concat_strs", {"vals": '["a", "b", "c"]'})
-            assert isinstance(result, list)
-            assert len(result) == 1
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "abc"
+            assert result[0].text == "abc"  # type: ignore[attr-defined]
 
             result = await manager.call_tool("concat_strs", {"vals": '"a"'})
-            assert isinstance(result, list)
-            assert len(result) == 1
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "a"
+            assert result[0].text == "a"  # type: ignore[attr-defined]
 
     async def test_call_tool_with_complex_model(self):
         class MyShrimpTank(BaseModel):
@@ -507,10 +465,7 @@ class TestCallTools:
                 },
             )
 
-        assert isinstance(result, list)
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == '[\n  "rex",\n  "gertrude"\n]'
+        assert result[0].text == '[\n  "rex",\n  "gertrude"\n]'  # type: ignore[attr-defined]
 
     async def test_call_tool_with_custom_serializer(self):
         """Test that a custom serializer provided to FastMCP is used by tools."""
@@ -530,10 +485,7 @@ class TestCallTools:
         manager.add_tool_from_fn(get_data)
 
         result = await manager.call_tool("get_data", {})
-        assert isinstance(result, list)
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == 'CUSTOM:{"key": "value", "number": 123}'
+        assert result[0].text == 'CUSTOM:{"key": "value", "number": 123}'  # type: ignore[attr-defined]
 
     async def test_call_tool_with_list_result_custom_serializer(self):
         """Test that a custom serializer provided to FastMCP is used by tools that return lists."""
@@ -555,12 +507,9 @@ class TestCallTools:
         manager.add_tool_from_fn(get_data)
 
         result = await manager.call_tool("get_data", {})
-        assert isinstance(result, list)
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
         assert (
-            result[0].text
-            == 'CUSTOM:[{"key": "value", "number": 123}, {"key": "value2", "number": 456}]'
+            result[0].text  # type: ignore[attr-defined]
+            == 'CUSTOM:[{"key": "value", "number": 123}, {"key": "value2", "number": 456}]'  # type: ignore[attr-defined]
         )
 
     async def test_custom_serializer_fallback_on_error(self):
@@ -580,10 +529,7 @@ class TestCallTools:
         manager.add_tool_from_fn(get_data)
 
         result = await manager.call_tool("get_data", {})
-        assert isinstance(result, list)
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == pydantic_core.to_json(uuid_result).decode()
+        assert result[0].text == pydantic_core.to_json(uuid_result).decode()  # type: ignore[attr-defined]
 
 
 class TestToolSchema:
@@ -648,10 +594,7 @@ class TestContextHandling:
 
         with context:
             result = await manager.call_tool("tool_with_context", {"x": 42})
-            assert isinstance(result, list)
-            assert len(result) == 1
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "42"
+            assert result[0].text == "42"  # type: ignore[attr-defined]
 
     async def test_context_injection_async(self):
         """Test that context is properly injected in async tools."""
@@ -668,14 +611,10 @@ class TestContextHandling:
 
         with context:
             result = await manager.call_tool("async_tool", {"x": 42})
-            assert isinstance(result, list)
-            assert len(result) == 1
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "42"
+            assert result[0].text == "42"  # type: ignore[attr-defined]
 
     async def test_context_optional(self):
         """Test that context is optional when calling tools."""
-        from mcp.types import TextContent
 
         def tool_with_context(x: int, ctx: Context | None) -> int:
             return x
@@ -689,10 +628,7 @@ class TestContextHandling:
 
         with context:
             result = await manager.call_tool("tool_with_context", {"x": 42})
-            assert isinstance(result, list)
-            assert len(result) == 1
-            assert isinstance(result[0], TextContent)
-            assert result[0].text == "42"
+            assert result[0].text == "42"  # type: ignore[attr-defined]
 
     def test_parameterized_context_parameter_detection(self):
         """Test that context parameters are properly detected in
@@ -782,7 +718,6 @@ class TestCustomToolNames:
 
     async def test_call_tool_with_custom_name(self):
         """Test calling a tool added with a custom name."""
-        from mcp.types import TextContent
 
         def multiply(a: int, b: int) -> int:
             """Multiply two numbers."""
@@ -793,11 +728,7 @@ class TestCustomToolNames:
 
         # Tool should be callable by its custom name
         result = await manager.call_tool("custom_multiply", {"a": 5, "b": 3})
-        assert isinstance(result, list)
-        assert len(result) == 1
-        assert isinstance(result[0], TextContent)
-        assert result[0].text == "15"
-        assert json.loads(result[0].text) == 15
+        assert result[0].text == "15"  # type: ignore[attr-defined]
 
         # Original name should not be registered
         with pytest.raises(NotFoundError, match="Unknown tool: multiply"):

tests/utilities/test_mcp_config.py

@@ -1,8 +1,6 @@
 import inspect
 from pathlib import Path
 
-from mcp.types import TextContent
-
 from fastmcp.client.client import Client
 from fastmcp.client.transports import (
     SSETransport,
@@ -136,7 +134,5 @@ async def test_multi_client(tmp_path: Path):
 
         result_1 = await client.call_tool("test_1_add", {"a": 1, "b": 2})
         result_2 = await client.call_tool("test_2_add", {"a": 1, "b": 2})
-        assert isinstance(result_1[0], TextContent)
-        assert result_1[0].text == "3"
-        assert isinstance(result_2[0], TextContent)
-        assert result_2[0].text == "3"
+        assert result_1[0].text == "3"  # type: ignore[attr-dict]
+        assert result_2[0].text == "3"  # type: ignore[attr-dict]