fix: environment variable handling for stdio mcp (#3340)

Co-authored-by: Jin Peng <jinjpeng@Jins-MacBook-Pro.local>

letta/server/rest_api/routers/v1/tools.py

@@ -20,7 +20,7 @@ from letta.helpers.composio_helpers import get_composio_api_key
 from letta.log import get_logger
 from letta.orm.errors import UniqueConstraintViolationError
 from letta.schemas.letta_message import ToolReturnMessage
-from letta.schemas.mcp import UpdateSSEMCPServer, UpdateStreamableHTTPMCPServer
+from letta.schemas.mcp import UpdateSSEMCPServer, UpdateStdioMCPServer, UpdateStreamableHTTPMCPServer
 from letta.schemas.tool import Tool, ToolCreate, ToolRunFromSource, ToolUpdate
 from letta.server.rest_api.utils import get_letta_server
 from letta.server.server import SyncServer
@@ -550,7 +550,7 @@ async def add_mcp_server_to_config(
 )
 async def update_mcp_server(
     mcp_server_name: str,
-    request: Union[UpdateSSEMCPServer, UpdateStreamableHTTPMCPServer] = Body(...),
+    request: Union[UpdateStdioMCPServer, UpdateSSEMCPServer, UpdateStreamableHTTPMCPServer] = Body(...),
     server: SyncServer = Depends(get_letta_server),
     actor_id: Optional[str] = Header(None, alias="user_id"),
 ):

letta/services/mcp/stdio_client.py

@@ -11,11 +11,10 @@ logger = get_logger(__name__)
 # TODO: Get rid of Async prefix on this class name once we deprecate old sync code
 class AsyncStdioMCPClient(AsyncBaseMCPClient):
     async def _initialize_connection(self, server_config: StdioServerConfig) -> None:
-
         args = [arg.split() for arg in server_config.args]
         # flatten
         args = [arg for sublist in args for arg in sublist]
-        server_params = StdioServerParameters(command=server_config.command, args=args)
+        server_params = StdioServerParameters(command=server_config.command, args=args, env=server_config.env)
         stdio_transport = await self.exit_stack.enter_async_context(stdio_client(server_params))
         self.stdio, self.write = stdio_transport
         self.session = await self.exit_stack.enter_async_context(ClientSession(self.stdio, self.write))