fix(agent): make MCP HTTP server import compatible with pydantic-ai 1.x

rdagent/components/agent/base.py

@@ -4,8 +4,8 @@
 from prefect import task
 from prefect.cache_policies import INPUTS
 from pydantic_ai import Agent
-from pydantic_ai.mcp import MCPServerStreamableHTTP
 
+from rdagent.components.agent.mcp_compat import MCPServerHTTP
 from rdagent.oai.backend.pydantic_ai import get_agent_model
 
 
@@ -29,7 +29,7 @@ class PAIAgent(BaseAgent):
     def __init__(
         self,
         system_prompt: str,
-        toolsets: list[str | MCPServerStreamableHTTP],
+        toolsets: list[str | MCPServerHTTP],
         enable_cache: bool = False,
     ):
         """
@@ -39,13 +39,13 @@ def __init__(
         ----------
         system_prompt : str
             System prompt for the agent
-        toolsets : list[str | MCPServerStreamableHTTP]
+        toolsets : list[str | MCPServerHTTP]
             List of MCP server URLs or instances
         enable_cache : bool
             Enable persistent caching via Prefect. Requires Prefect server:
             `prefect server start` then set PREFECT_API_URL in environment
         """
-        toolsets = [(ts if isinstance(ts, MCPServerStreamableHTTP) else MCPServerStreamableHTTP(ts)) for ts in toolsets]
+        toolsets = [(ts if isinstance(ts, MCPServerHTTP) else MCPServerHTTP(ts)) for ts in toolsets]
         self.agent = Agent(get_agent_model(), system_prompt=system_prompt, toolsets=toolsets)
         self.enable_cache = enable_cache
 

rdagent/components/agent/context7/__init__.py

@@ -1,20 +1,20 @@
 from typing import Optional
 
-from pydantic_ai.mcp import MCPServerStreamableHTTP
-
 from rdagent.components.agent.base import PAIAgent
 from rdagent.components.agent.context7.conf import SETTINGS
 from rdagent.log import rdagent_logger as logger
 from rdagent.utils.agent.tpl import T
 
+from ..mcp_compat import MCPServerHTTP
+
 
 class Agent(PAIAgent):
     """
     A specific agent for context7
     """
 
     def __init__(self):
-        toolsets = [MCPServerStreamableHTTP(SETTINGS.url, timeout=SETTINGS.timeout)]
+        toolsets = [MCPServerHTTP(SETTINGS.url, timeout=SETTINGS.timeout)]
 
         super().__init__(
             system_prompt=T(".prompts:system_prompt").r(),

rdagent/components/agent/mcp_compat.py

@@ -0,0 +1,20 @@
+"""Compatibility shim for the pydantic-ai MCP HTTP server class.
+
+pydantic-ai renamed ``MCPServerStreamableHTTP`` to ``MCPServerHTTP`` during the
+1.x line; both names are still exported there, but newer 1.x versions only
+document the new name. The 2.x line reworked the MCP API entirely
+(``MCPToolsetClient``) and requires a separate migration, so RD-Agent keeps
+``pydantic-ai-slim<2`` in ``requirements.txt``.
+
+Importing through this module keeps the agent components working across every
+1.x release regardless of which name is available.
+"""
+
+from __future__ import annotations
+
+try:
+    from pydantic_ai.mcp import MCPServerHTTP
+except ImportError:  # pragma: no cover - only hit on old pydantic-ai 1.x
+    from pydantic_ai.mcp import MCPServerStreamableHTTP as MCPServerHTTP
+
+__all__ = ["MCPServerHTTP"]

rdagent/components/agent/rag/__init__.py

@@ -1,17 +1,17 @@
-from pydantic_ai.mcp import MCPServerStreamableHTTP
-
 from rdagent.components.agent.base import PAIAgent
 from rdagent.components.agent.rag.conf import SETTINGS
 from rdagent.utils.agent.tpl import T
 
+from ..mcp_compat import MCPServerHTTP
+
 
 class Agent(PAIAgent):
     """
     A specific agent for RAG
     """
 
     def __init__(self, system_prompt: str | None = None):
-        toolsets = [MCPServerStreamableHTTP(SETTINGS.url, timeout=SETTINGS.timeout)]
+        toolsets = [MCPServerHTTP(SETTINGS.url, timeout=SETTINGS.timeout)]
         if system_prompt is None:
             system_prompt = "You are a Retrieval-Augmented Generation (RAG) agent. Use the retrieved documents to answer the user's queries accurately and concisely."
         super().__init__(system_prompt=system_prompt, toolsets=toolsets)

requirements.txt

@@ -72,7 +72,7 @@ azureml-mlflow
 types-pytz
 
 # Agent
-pydantic-ai-slim[mcp,openai,prefect]==1.66.0
+pydantic-ai-slim[mcp,openai,prefect]==1.107.4  # keep <2: MCP API reworked in 2.x (see #1432)
 nest-asyncio
 
 # visualize SFT train
@@ -83,4 +83,4 @@ prefect
 datasets
 
 # DuckDuckGo search
-duckduckgo-search
+duckduckgo-search

test/utils/test_mcp_compat.py

@@ -0,0 +1,16 @@
+from rdagent.components.agent.mcp_compat import MCPServerHTTP
+
+"""pydantic-ai renamed ``MCPServerStreamableHTTP`` to ``MCPServerHTTP`` in 1.x.
+
+The compat layer must resolve to whichever name the installed pydantic-ai
+exposes so agent components keep working across 1.x releases.
+"""
+
+
+def test_importable() -> None:
+    assert callable(MCPServerHTTP)
+
+
+def test_construct_with_url() -> None:
+    server = MCPServerHTTP("http://127.0.0.1:8080", timeout=5)
+    assert str(server.url) == "http://127.0.0.1:8080"