feat: init pydantic ai agent & context 7 mcp (#1240)

* feat: init pydantic ai agent & context 7 mcp

* feat: integrate MCP documentation search into data science pipeline evaluation

* fix: disable MCP documentation search and update related docstrings and defaults

* lint

* fix: correct prompt formatting and conditional blocks in pipeline_eval section

* lint

* feat: add query method to PAIAgent for synchronous agent execution

* fix: apply nest_asyncio for agent and update context7 query method

* lint

* lint

* lint

* lint

* docs: update MCP folder docstring and rename test class in test_pydantic.py

* refactor: centralize completion kwargs logic and update pydantic_ai integration

* fixbug

* typo

* fix: bug triggered by padantic-ai version backtracking.

---------

Co-authored-by: Linlang <Lv.Linlang@hotmail.com>

rdagent/components/agent/base.py

@@ -0,0 +1,44 @@
+from abc import abstractmethod
+
+import nest_asyncio
+from pydantic_ai import Agent
+from pydantic_ai.mcp import MCPServerStreamableHTTP
+
+from rdagent.oai.backend.pydantic_ai import get_agent_model
+
+
+class BaseAgent:
+
+    @abstractmethod
+    def __init__(self, system_prompt: str, toolsets: list[str]): ...
+
+    @abstractmethod
+    def query(self, query: str) -> str: ...
+
+
+class PAIAgent(BaseAgent):
+    """
+    Pydantic-AI agent
+    """
+
+    agent: Agent
+
+    def __init__(self, system_prompt: str, toolsets: list[str | MCPServerStreamableHTTP]):
+        toolsets = [(ts if isinstance(ts, MCPServerStreamableHTTP) else MCPServerStreamableHTTP(ts)) for ts in toolsets]
+        self.agent = Agent(get_agent_model(), system_prompt=system_prompt, toolsets=toolsets)
+
+    def query(self, query: str) -> str:
+        """
+
+        Parameters
+        ----------
+        query : str
+
+        Returns
+        -------
+        str
+        """
+
+        nest_asyncio.apply()  # NOTE: very important. Because pydantic-ai uses asyncio!
+        result = self.agent.run_sync(query)
+        return result.output