feat: add official way to use MCP Tools within a CrewBase (#3058)

docs/mcp/overview.mdx

@@ -101,6 +101,41 @@ with MCPServerAdapter(server_params) as mcp_tools:
     )
     # ... rest of your crew setup ...
 ```
+
+## Using with CrewBase
+
+To use MCPServer tools within a CrewBase class, use the `mcp_tools` method. Server configurations should be provided via the mcp_server_params attribute. You can pass either a single configuration or a list of multiple server configurations.
+
+```python
+@CrewBase
+class CrewWithMCP:
+  # ... define your agents and tasks config file ...
+
+  mcp_server_params = [
+    # Streamable HTTP Server
+    {
+        "url": "http://localhost:8001/mcp",
+        "transport": "streamable-http"
+    },
+    # SSE Server
+    {
+        "url": "http://localhost:8000/sse",
+        "transport": "sse"
+    },
+    # StdIO Server
+    StdioServerParameters(
+        command="python3",
+        args=["servers/your_stdio_server.py"],
+        env={"UV_PYTHON": "3.12", **os.environ},
+    )
+  ]
+
+  @agent
+  def your_agent(self):
+      return Agent(config=self.agents_config["your_agent"], tools=self.get_mcp_tools()) # you can filter which tool are available also
+
+    # ... rest of your crew setup ...
+```
 ## Explore MCP Integrations
 
 <CardGroup cols={2}>

src/crewai/project/crew_base.py

@@ -1,7 +1,8 @@
 import inspect
 import logging
 from pathlib import Path
-from typing import Any, Callable, Dict, TypeVar, cast
+from typing import Any, Callable, Dict, TypeVar, cast, List
+from crewai.tools import BaseTool
 
 import yaml
 from dotenv import load_dotenv
@@ -27,6 +28,8 @@ def CrewBase(cls: T) -> T:
         )
         original_tasks_config_path = getattr(cls, "tasks_config", "config/tasks.yaml")
 
+        mcp_server_params: Any = getattr(cls, "mcp_server_params", None)
+
         def __init__(self, *args, **kwargs):
             super().__init__(*args, **kwargs)
             self.load_configurations()
@@ -64,6 +67,39 @@ def CrewBase(cls: T) -> T:
                 self._original_functions, "is_kickoff"
             )
 
+            # Add close mcp server method to after kickoff
+            bound_method = self._create_close_mcp_server_method()
+            self._after_kickoff['_close_mcp_server'] = bound_method
+
+        def _create_close_mcp_server_method(self):
+            def _close_mcp_server(self, instance, outputs):
+                adapter = getattr(self, '_mcp_server_adapter', None)
+                if adapter is not None:
+                    try:
+                        adapter.stop()
+                    except Exception as e:
+                        logging.warning(f"Error stopping MCP server: {e}")
+                return outputs
+
+            _close_mcp_server.is_after_kickoff = True
+
+            import types
+            return types.MethodType(_close_mcp_server, self)
+
+        def get_mcp_tools(self) -> List[BaseTool]:
+            if not self.mcp_server_params:
+                return []
+
+            from crewai_tools import MCPServerAdapter
+
+            adapter = getattr(self, '_mcp_server_adapter', None)
+            if adapter and isinstance(adapter, MCPServerAdapter):
+                return adapter.tools
+
+            self._mcp_server_adapter = MCPServerAdapter(self.mcp_server_params)
+            return self._mcp_server_adapter.tools
+
+
         def load_configurations(self):
             """Load agent and task configurations from YAML files."""
             if isinstance(self.original_agents_config_path, str):

tests/project_test.py

@@ -1,5 +1,5 @@
 from typing import List
-
+from unittest.mock import Mock, patch
 import pytest
 
 from crewai.agent import Agent
@@ -16,7 +16,7 @@ from crewai.project import (
     task,
 )
 from crewai.task import Task
-
+from crewai.tools import tool
 
 class SimpleCrew:
     @agent
@@ -85,6 +85,14 @@ class InternalCrew:
     def crew(self):
         return Crew(agents=self.agents, tasks=self.tasks, verbose=True)
 
+@CrewBase
+class InternalCrewWithMCP(InternalCrew):
+    mcp_server_params = {"host": "localhost", "port": 8000}
+
+    @agent
+    def reporting_analyst(self):
+        return Agent(config=self.agents_config["reporting_analyst"], tools=self.get_mcp_tools())  # type: ignore[index]
+
 
 def test_agent_memoization():
     crew = SimpleCrew()
@@ -237,3 +245,17 @@ def test_multiple_before_after_kickoff():
 def test_crew_name():
     crew = InternalCrew()
     assert crew._crew_name == "InternalCrew"
+
+@tool
+def simple_tool():
+    """Return 'Hi!'"""
+    return "Hi!"
+
+def test_internal_crew_with_mcp():
+    mock = Mock()
+    mock.tools = [simple_tool]
+    with patch("crewai_tools.MCPServerAdapter", return_value=mock) as adapter_mock:
+        crew = InternalCrewWithMCP()
+        assert crew.reporting_analyst().tools == [simple_tool]
+
+    adapter_mock.assert_called_once_with({"host": "localhost", "port": 8000})