From d1ac8d68eb2d7ed139bdc2608b8b4e2ec4265be5 Mon Sep 17 00:00:00 2001
From: Moustapha Ebnou <155577789+mous222@users.noreply.github.com>
Date: Thu, 14 Aug 2025 14:51:59 +0200
Subject: [PATCH] fix: prevent async generator cleanup errors in StreamableHTTP
 transport (#1271)

Co-authored-by: David Soria Parra <167242713+dsp-ant@users.noreply.github.com>
---
 src/mcp/client/streamable_http.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/mcp/client/streamable_http.py b/src/mcp/client/streamable_http.py
index b749e210..b1ab2c07 100644
--- a/src/mcp/client/streamable_http.py
+++ b/src/mcp/client/streamable_http.py
@@ -248,6 +248,7 @@ class StreamableHTTPTransport:
                     ctx.metadata.on_resumption_token_update if ctx.metadata else None,
                 )
                 if is_complete:
+                    await event_source.response.aclose()
                     break
 
     async def _handle_post_request(self, ctx: RequestContext) -> None:
@@ -330,6 +331,7 @@ class StreamableHTTPTransport:
                 # If the SSE event indicates completion, like returning respose/error
                 # break the loop
                 if is_complete:
+                    await response.aclose()
                     break
         except Exception as e:
             logger.exception("Error reading SSE stream:")