chore: improved type annotations in MCP-related codes (#23984)

api/core/mcp/client/sse_client.py

@@ -7,6 +7,7 @@ from typing import Any, TypeAlias, final
 from urllib.parse import urljoin, urlparse
 
 import httpx
+from httpx_sse import EventSource, ServerSentEvent
 from sseclient import SSEClient
 
 from core.mcp import types
@@ -114,7 +115,7 @@ class SSETransport:
             logger.exception("Error parsing server message")
             read_queue.put(exc)
 
-    def _handle_sse_event(self, sse, read_queue: ReadQueue, status_queue: StatusQueue) -> None:
+    def _handle_sse_event(self, sse: ServerSentEvent, read_queue: ReadQueue, status_queue: StatusQueue) -> None:
         """Handle a single SSE event.
 
         Args:
@@ -130,7 +131,7 @@ class SSETransport:
             case _:
                 logger.warning("Unknown SSE event: %s", sse.event)
 
-    def sse_reader(self, event_source, read_queue: ReadQueue, status_queue: StatusQueue) -> None:
+    def sse_reader(self, event_source: EventSource, read_queue: ReadQueue, status_queue: StatusQueue) -> None:
         """Read and process SSE events.
 
         Args:
@@ -225,7 +226,7 @@ class SSETransport:
         self,
         executor: ThreadPoolExecutor,
         client: httpx.Client,
-        event_source,
+        event_source: EventSource,
     ) -> tuple[ReadQueue, WriteQueue]:
         """Establish connection and start worker threads.