Refactor MCP shims to avoid litellm import cycles

aider/coders/agent_coder.py

@@ -14,14 +14,8 @@
 from datetime import datetime
 from pathlib import Path
 
-from litellm import experimental_mcp_client
-
 from aider import urls, utils
-
-# Import the change tracker
 from aider.change_tracker import ChangeTracker
-
-# Import similarity functions for tool usage analysis
 from aider.helpers.similarity import (
     cosine_similarity,
     create_bigram_vector,
@@ -30,7 +24,7 @@
 
 # Import skills helper for skills
 from aider.helpers.skills import SkillsManager
-from aider.mcp.server import LocalServer
+from aider.mcp_support.server import LocalServer
 from aider.repo import ANY_GIT_ERROR
 
 # Import tool modules for registry
@@ -77,6 +71,25 @@
 from .editblock_coder import do_replace, find_original_update_blocks, find_similar_lines
 
 
+class _ExperimentalMCPClientProxy:
+    """Lazy proxy to defer importing litellm.experimental_mcp_client."""
+
+    _client = None
+
+    def _get_client(self):
+        if self._client is None:
+            from litellm import experimental_mcp_client as client
+
+            self._client = client
+        return self._client
+
+    def __getattr__(self, name):
+        return getattr(self._get_client(), name)
+
+
+experimental_mcp_client = _ExperimentalMCPClientProxy()
+
+
 class AgentCoder(Coder):
     """Mode where the LLM autonomously manages which files are in context."""
 

aider/coders/base_coder.py

@@ -29,7 +29,6 @@
 from typing import List
 
 import httpx
-from litellm import experimental_mcp_client
 from litellm.types.utils import ModelResponse
 from prompt_toolkit.patch_stdout import patch_stdout
 from rich.console import Console
@@ -42,7 +41,7 @@
 from aider.io import ConfirmGroup, InputOutput
 from aider.linter import Linter
 from aider.llm import litellm
-from aider.mcp.server import LocalServer
+from aider.mcp_support.server import LocalServer
 from aider.models import RETRY_TIMEOUT
 from aider.reasoning_tags import (
     REASONING_TAG,
@@ -61,6 +60,25 @@
 from .chat_chunks import ChatChunks
 
 
+class _ExperimentalMCPClientProxy:
+    """Lazy proxy to defer importing litellm.experimental_mcp_client."""
+
+    _client = None
+
+    def _get_client(self):
+        if self._client is None:
+            from litellm import experimental_mcp_client as client
+
+            self._client = client
+        return self._client
+
+    def __getattr__(self, name):
+        return getattr(self._get_client(), name)
+
+
+experimental_mcp_client = _ExperimentalMCPClientProxy()
+
+
 class UnknownEditFormat(ValueError):
     def __init__(self, edit_format, valid_formats):
         self.edit_format = edit_format

aider/main.py

@@ -48,7 +48,7 @@
 from aider.history import ChatSummary
 from aider.io import InputOutput
 from aider.llm import litellm  # noqa: F401; properly init litellm on launch
-from aider.mcp import load_mcp_servers
+from aider.mcp_support import load_mcp_servers
 from aider.models import ModelSettings
 from aider.onboarding import offer_openrouter_oauth, select_default_model
 from aider.repo import ANY_GIT_ERROR, GitRepo

aider/mcp/__init__.py → aider/mcp_support/__init__.py

@@ -1,7 +1,17 @@
 import json
 from pathlib import Path
 
-from aider.mcp.server import HttpStreamingServer, McpServer, SseServer
+
+def _create_server_from_config(server_config, transport):
+    from .server import HttpStreamingServer, McpServer, SseServer
+
+    if transport == "stdio":
+        return McpServer(server_config)
+    if transport == "http":
+        return HttpStreamingServer(server_config)
+    if transport == "sse":
+        return SseServer(server_config)
+    return None
 
 
 def _parse_mcp_servers_from_json_string(json_string, io, verbose=False, mcp_transport="stdio"):
@@ -21,12 +31,9 @@ def _parse_mcp_servers_from_json_string(json_string, io, verbose=False, mcp_tran
                 # Create a server config with name included
                 server_config["name"] = name
                 transport = server_config.get("transport", mcp_transport)
-                if transport == "stdio":
-                    servers.append(McpServer(server_config))
-                elif transport == "http":
-                    servers.append(HttpStreamingServer(server_config))
-                elif transport == "sse":
-                    servers.append(SseServer(server_config))
+                server = _create_server_from_config(server_config, transport)
+                if server:
+                    servers.append(server)
 
             if verbose:
                 io.tool_output(f"Loaded {len(servers)} MCP servers from JSON string")
@@ -120,10 +127,9 @@ def _parse_mcp_servers_from_file(file_path, io, verbose=False, mcp_transport="st
                 # Create a server config with name included
                 server_config["name"] = name
                 transport = server_config.get("transport", mcp_transport)
-                if transport == "stdio":
-                    servers.append(McpServer(server_config))
-                elif transport == "http":
-                    servers.append(HttpStreamingServer(server_config))
+                server = _create_server_from_config(server_config, transport)
+                if server:
+                    servers.append(server)
 
             if verbose:
                 io.tool_output(f"Loaded {len(servers)} MCP servers from {file_path}")
@@ -169,6 +175,7 @@ def load_mcp_servers(mcp_servers, mcp_servers_file, io, verbose=False, mcp_trans
         # and maybe it is actually prompt_toolkit's fault
         # but this hack works swimmingly because ???
         # so sure! why not
-        servers = [McpServer(json.loads('{"aider_default": {}}'))]
+        default_server = _create_server_from_config(json.loads('{"aider_default": {}}'), "stdio")
+        servers = [default_server] if default_server else []
 
     return servers