fix(mcp): Restore synchronous dispatch and update mcp_server to use async_dispatch.

scripts/mcp_server.py

@@ -70,9 +70,10 @@ async def call_tool(name: str, arguments: dict) -> list[TextContent]:
  try:
   if name == "run_powershell":
    script = arguments.get("script", "")
-   result = shell_runner.run_powershell(script, os.getcwd())
+   # run_powershell is synchronous, so we run it in a thread to avoid blocking the loop
+   result = await asyncio.to_thread(shell_runner.run_powershell, script, os.getcwd())
   else:
-   result = mcp_client.dispatch(name, arguments)
+   result = await mcp_client.async_dispatch(name, arguments)
   return [TextContent(type="text", text=str(result))]
  except Exception as e:
   return [TextContent(type="text", text=f"ERROR: {e}")]

src/mcp_client.py

@@ -859,88 +859,82 @@ def get_ui_performance() -> str:
 
 TOOL_NAMES: set[str] = {"read_file", "list_directory", "search_files", "get_file_summary", "py_get_skeleton", "py_get_code_outline", "py_get_definition", "get_git_diff", "web_search", "fetch_url", "get_ui_performance", "get_file_slice", "set_file_slice", "edit_file", "py_update_definition", "py_get_signature", "py_set_signature", "py_get_class_summary", "py_get_var_declaration", "py_set_var_declaration", "py_find_usages", "py_get_imports", "py_check_syntax", "py_get_hierarchy", "py_get_docstring", "get_tree"}
 
-async def async_dispatch(tool_name: str, tool_input: dict[str, Any]) -> str:
+def dispatch(tool_name: str, tool_input: dict[str, Any]) -> str:
  """
- Dispatch an MCP tool call by name asynchronously. Returns the result as a string.
+    Dispatch an MCP tool call by name.  Returns the result as a string.
     """
  # Handle aliases
  path = str(tool_input.get("path", tool_input.get("file_path", tool_input.get("dir_path", ""))))
  if tool_name == "read_file":
-  return await asyncio.to_thread(read_file, path)
+  return read_file(path)
  if tool_name == "list_directory":
-  return await asyncio.to_thread(list_directory, path)
+  return list_directory(path)
  if tool_name == "search_files":
-  return await asyncio.to_thread(search_files, path, str(tool_input.get("pattern", "*")))
+  return search_files(path, str(tool_input.get("pattern", "*")))
  if tool_name == "get_file_summary":
-  return await asyncio.to_thread(get_file_summary, path)
+  return get_file_summary(path)
  if tool_name == "py_get_skeleton":
-  return await asyncio.to_thread(py_get_skeleton, path)
+  return py_get_skeleton(path)
  if tool_name == "py_get_code_outline":
-  return await asyncio.to_thread(py_get_code_outline, path)
+  return py_get_code_outline(path)
  if tool_name == "py_get_definition":
-  return await asyncio.to_thread(py_get_definition, path, str(tool_input.get("name", "")))
+  return py_get_definition(path, str(tool_input.get("name", "")))
  if tool_name == "py_update_definition":
-  return await asyncio.to_thread(py_update_definition, path, str(tool_input.get("name", "")), str(tool_input.get("new_content", "")))
+  return py_update_definition(path, str(tool_input.get("name", "")), str(tool_input.get("new_content", "")))
  if tool_name == "py_get_signature":
-  return await asyncio.to_thread(py_get_signature, path, str(tool_input.get("name", "")))
+  return py_get_signature(path, str(tool_input.get("name", "")))
  if tool_name == "py_set_signature":
-  return await asyncio.to_thread(py_set_signature, path, str(tool_input.get("name", "")), str(tool_input.get("new_signature", "")))
+  return py_set_signature(path, str(tool_input.get("name", "")), str(tool_input.get("new_signature", "")))
  if tool_name == "py_get_class_summary":
-  return await asyncio.to_thread(py_get_class_summary, path, str(tool_input.get("name", "")))
+  return py_get_class_summary(path, str(tool_input.get("name", "")))
  if tool_name == "py_get_var_declaration":
-  return await asyncio.to_thread(py_get_var_declaration, path, str(tool_input.get("name", "")))
+  return py_get_var_declaration(path, str(tool_input.get("name", "")))
  if tool_name == "py_set_var_declaration":
-  return await asyncio.to_thread(py_set_var_declaration, path, str(tool_input.get("name", "")), str(tool_input.get("new_declaration", "")))
+  return py_set_var_declaration(path, str(tool_input.get("name", "")), str(tool_input.get("new_declaration", "")))
  if tool_name == "get_file_slice":
-  return await asyncio.to_thread(get_file_slice, path, int(tool_input.get("start_line", 1)), int(tool_input.get("end_line", 1)))
+  return get_file_slice(path, int(tool_input.get("start_line", 1)), int(tool_input.get("end_line", 1)))
  if tool_name == "set_file_slice":
-  return await asyncio.to_thread(set_file_slice, path, int(tool_input.get("start_line", 1)), int(tool_input.get("end_line", 1)), str(tool_input.get("new_content", "")))
+  return set_file_slice(path, int(tool_input.get("start_line", 1)), int(tool_input.get("end_line", 1)), str(tool_input.get("new_content", "")))
  if tool_name == "get_git_diff":
-  return await asyncio.to_thread(get_git_diff,
+  return get_git_diff(
    path, 
    str(tool_input.get("base_rev", "HEAD")), 
    str(tool_input.get("head_rev", ""))
   )
  if tool_name == "edit_file":
-  return await asyncio.to_thread(edit_file,
+  return edit_file(
    path,
    str(tool_input.get("old_string", "")),
    str(tool_input.get("new_string", "")),
    bool(tool_input.get("replace_all", False))
   )
  if tool_name == "web_search":
-  return await asyncio.to_thread(web_search, str(tool_input.get("query", "")))
+  return web_search(str(tool_input.get("query", "")))
  if tool_name == "fetch_url":
-  return await asyncio.to_thread(fetch_url, str(tool_input.get("url", "")))
+  return fetch_url(str(tool_input.get("url", "")))
  if tool_name == "get_ui_performance":
-  return await asyncio.to_thread(get_ui_performance)
+  return get_ui_performance()
  if tool_name == "py_find_usages":
-  return await asyncio.to_thread(py_find_usages, path, str(tool_input.get("name", "")))
+  return py_find_usages(path, str(tool_input.get("name", "")))
  if tool_name == "py_get_imports":
-  return await asyncio.to_thread(py_get_imports, path)
+  return py_get_imports(path)
  if tool_name == "py_check_syntax":
-  return await asyncio.to_thread(py_check_syntax, path)
+  return py_check_syntax(path)
  if tool_name == "py_get_hierarchy":
-  return await asyncio.to_thread(py_get_hierarchy, path, str(tool_input.get("class_name", "")))
+  return py_get_hierarchy(path, str(tool_input.get("class_name", "")))
  if tool_name == "py_get_docstring":
-  return await asyncio.to_thread(py_get_docstring, path, str(tool_input.get("name", "")))
+  return py_get_docstring(path, str(tool_input.get("name", "")))
  if tool_name == "get_tree":
-  return await asyncio.to_thread(get_tree, path, int(tool_input.get("max_depth", 2)))
+  return get_tree(path, int(tool_input.get("max_depth", 2)))
  return f"ERROR: unknown MCP tool '{tool_name}'"
 
-def dispatch(tool_name: str, tool_input: dict[str, Any]) -> str:
+async def async_dispatch(tool_name: str, tool_input: dict[str, Any]) -> str:
  """
-    Dispatch an MCP tool call by name.  Returns the result as a string.
+ Dispatch an MCP tool call by name asynchronously. Returns the result as a string.
  """
- try:
+ # Run blocking I/O bound tools in a thread to allow parallel execution via asyncio.gather
-  loop = asyncio.get_running_loop()
+ return await asyncio.to_thread(dispatch, tool_name, tool_input)
-  # If we are in a running loop, we can't use asyncio.run
+
-  # But we are in a synchronous function.
-  # This is tricky.  If we are in a thread, we might not have a loop.
-  return asyncio.run_coroutine_threadsafe(async_dispatch(tool_name, tool_input), loop).result()
- except RuntimeError:
-  # No running loop, use asyncio.run
-  return asyncio.run(async_dispatch(tool_name, tool_input))
 
 
 def get_tool_schemas() -> list[dict[str, Any]]: