PYTHON-5543 PyMongoBaseProtocol should inherit from asyncio.BaseProtocol (#2528)

aclark4life · NoahStapp · web-flow · commit 3da6e858d58b · 2025-09-11T16:37:22.000-04:00
Co-authored-by: Noah Stapp &lt;noah@noahstapp.com&gt;
diff --git a/doc/changelog.rst b/doc/changelog.rst
@@ -1,6 +1,14 @@
 Changelog
 =========
 
+Changes in Version 4.15.1 (XXXX/XX/XX)
+--------------------------------------
+
+Version 4.15.1 is a bug fix release.
+
+- Fixed a bug in ``AsyncMongoClient`` that caused a
+  ``ServerSelectionTimeoutError`` when used with ``uvicorn``, ``FastAPI``, or ``uvloop``.
+
 Changes in Version 4.15.0 (2025/09/10)
 --------------------------------------
 
diff --git a/pymongo/network_layer.py b/pymongo/network_layer.py
@@ -22,7 +22,7 @@
 import struct
 import sys
 import time
-from asyncio import BaseTransport, BufferedProtocol, Future, Protocol, Transport
+from asyncio import BaseProtocol, BaseTransport, BufferedProtocol, Future, Transport
 from typing import (
     TYPE_CHECKING,
     Any,
@@ -250,7 +250,7 @@ def recv_into(self, buffer: bytes | memoryview) -> int:
         return self.conn.recv_into(buffer)
 
 
-class PyMongoBaseProtocol(Protocol):
+class PyMongoBaseProtocol(BaseProtocol):
     def __init__(self, timeout: Optional[float] = None):
         self.transport: Transport = None  # type: ignore[assignment]
         self._timeout = timeout
