From b42b35a983ca4689659e060d4f2affeb51af3319 Mon Sep 17 00:00:00 2001
From: eyeonyou <example@example.com>
Date: Thu, 27 Mar 2025 17:22:32 +0300
Subject: [PATCH 01/10] fix(): SSE client handling of nested path URLs
Fix issue with SSE client failing when connecting to servers with nested paths (e.g., http://domain/path1/path2/sse). Previously, the client worked only with simple URLs like http://domain/sse.
The fix extracts the base path segment between domain and /sse endpoint using regex, then correctly constructs the response URL by preserving the path structure. This ensures proper communication with MCP servers hosted under non-root paths.
Without this fix, clients couldn't connect to SSE servers deployed under nested paths, as the endpoint URLs for posting messages were constructed incorrectly.
---
src/mcp/client/sse.py | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/src/mcp/client/sse.py b/src/mcp/client/sse.py
index 4f6241a72..a95428616 100644
--- a/src/mcp/client/sse.py
+++ b/src/mcp/client/sse.py
@@ -2,6 +2,7 @@
from contextlib import asynccontextmanager
from typing import Any
from urllib.parse import urljoin, urlparse
+import re
import anyio
import httpx
@@ -61,7 +62,9 @@ async def sse_reader(
logger.debug(f"Received SSE event: {sse.event}")
match sse.event:
case "endpoint":
- endpoint_url = urljoin(url, sse.data)
+ base_path = re.search(r"https?://[^/]+/(.+)/sse$", url)
+ base_path = base_path.group(1) if base_path else ""
+ endpoint_url = urljoin(url, base_path + sse.data)
logger.info(
f"Received endpoint URL: {endpoint_url}"
)
From 5a4d42053b48d1101f482b2de66699a5b8933c31 Mon Sep 17 00:00:00 2001
From: eyeonyou <example@example.com>
Date: Thu, 27 Mar 2025 17:43:59 +0300
Subject: [PATCH 02/10] style: format max-line
---
src/mcp/client/sse.py | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/src/mcp/client/sse.py b/src/mcp/client/sse.py
index a95428616..ffbb4ba7d 100644
--- a/src/mcp/client/sse.py
+++ b/src/mcp/client/sse.py
@@ -62,9 +62,15 @@ async def sse_reader(
logger.debug(f"Received SSE event: {sse.event}")
match sse.event:
case "endpoint":
- base_path = re.search(r"https?://[^/]+/(.+)/sse$", url)
- base_path = base_path.group(1) if base_path else ""
- endpoint_url = urljoin(url, base_path + sse.data)
+ base_path = re.search(
+ r"https?://[^/]+/(.+)/sse$", url
+ )
+ base_path = (
+ base_path.group(1) if base_path else ""
+ )
+ endpoint_url = urljoin(
+ url, base_path + sse.data
+ )
logger.info(
f"Received endpoint URL: {endpoint_url}"
)
From 21a775f21e12e2a03b7141acc4bc8d8ac99bf82e Mon Sep 17 00:00:00 2001
From: eyeonyou <example@example.com>
Date: Fri, 28 Mar 2025 08:11:35 +0300
Subject: [PATCH 03/10] fix: imports
---
src/mcp/client/sse.py | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/mcp/client/sse.py b/src/mcp/client/sse.py
index ffbb4ba7d..f78228524 100644
--- a/src/mcp/client/sse.py
+++ b/src/mcp/client/sse.py
@@ -1,8 +1,8 @@
import logging
+import re
from contextlib import asynccontextmanager
from typing import Any
from urllib.parse import urljoin, urlparse
-import re
import anyio
import httpx
From 9a58b30886d3e044a2a206de31e287a4d7c962e1 Mon Sep 17 00:00:00 2001
From: Jonathan Lima <jonathan.lima@securityscorecard.io>
Date: Mon, 7 Apr 2025 17:38:24 -0300
Subject: [PATCH 04/10] fixing /mcp case prefix on langchain
---
src/mcp/client/sse.py | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/src/mcp/client/sse.py b/src/mcp/client/sse.py
index f78228524..298361326 100644
--- a/src/mcp/client/sse.py
+++ b/src/mcp/client/sse.py
@@ -62,20 +62,22 @@ async def sse_reader(
logger.debug(f"Received SSE event: {sse.event}")
match sse.event:
case "endpoint":
+ url_parsed = urlparse(url)
+
base_path = re.search(
- r"https?://[^/]+/(.+)/sse$", url
+ r"https?://[^/]+/(.+?)(?:/mcp)?/sse$", url
)
base_path = (
base_path.group(1) if base_path else ""
)
endpoint_url = urljoin(
- url, base_path + sse.data
+ url_parsed.scheme + "://" + url_parsed.netloc,
+ base_path + sse.data
)
logger.info(
f"Received endpoint URL: {endpoint_url}"
)
- url_parsed = urlparse(url)
endpoint_parsed = urlparse(endpoint_url)
if (
url_parsed.netloc != endpoint_parsed.netloc
From 8e76e8a5c6fb48a7513e5173041694cafc26901d Mon Sep 17 00:00:00 2001
From: eyeonyou <example@example.com>
Date: Tue, 8 Apr 2025 10:45:23 +0300
Subject: [PATCH 05/10] style: Added noqa to avoid max-line of code
---
src/mcp/client/sse.py | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/mcp/client/sse.py b/src/mcp/client/sse.py
index 298361326..c41c414ed 100644
--- a/src/mcp/client/sse.py
+++ b/src/mcp/client/sse.py
@@ -71,7 +71,7 @@ async def sse_reader(
base_path.group(1) if base_path else ""
)
endpoint_url = urljoin(
- url_parsed.scheme + "://" + url_parsed.netloc,
+ url_parsed.scheme + "://" + url_parsed.netloc, # noqa: E501
base_path + sse.data
)
logger.info(
From e6d5b00991a9abcfe2469e2fed929d0113ad6e3a Mon Sep 17 00:00:00 2001
From: sebin1213 <73850629+sebin1213@users.noreply.github.com>
Date: Wed, 9 Apr 2025 02:02:49 +0000
Subject: [PATCH 06/10] Fix generate accurate session_uri for nested SSE paths
---
src/mcp/client/sse.py | 16 +++-------------
src/mcp/server/sse.py | 7 +++++--
2 files changed, 8 insertions(+), 15 deletions(-)
diff --git a/src/mcp/client/sse.py b/src/mcp/client/sse.py
index c41c414ed..0194c02a5 100644
--- a/src/mcp/client/sse.py
+++ b/src/mcp/client/sse.py
@@ -1,5 +1,4 @@
import logging
-import re
from contextlib import asynccontextmanager
from typing import Any
from urllib.parse import urljoin, urlparse
@@ -62,21 +61,12 @@ async def sse_reader(
logger.debug(f"Received SSE event: {sse.event}")
match sse.event:
case "endpoint":
- url_parsed = urlparse(url)
-
- base_path = re.search(
- r"https?://[^/]+/(.+?)(?:/mcp)?/sse$", url
- )
- base_path = (
- base_path.group(1) if base_path else ""
- )
- endpoint_url = urljoin(
- url_parsed.scheme + "://" + url_parsed.netloc, # noqa: E501
- base_path + sse.data
- )
+ endpoint_url = urljoin(url, sse.data)
logger.info(
f"Received endpoint URL: {endpoint_url}"
)
+
+ url_parsed = urlparse(url)
endpoint_parsed = urlparse(endpoint_url)
if (
diff --git a/src/mcp/server/sse.py b/src/mcp/server/sse.py
index d051c25bf..dbb40bed0 100644
--- a/src/mcp/server/sse.py
+++ b/src/mcp/server/sse.py
@@ -94,8 +94,11 @@ async def connect_sse(self, scope: Scope, receive: Receive, send: Send):
read_stream_writer, read_stream = anyio.create_memory_object_stream(0)
write_stream, write_stream_reader = anyio.create_memory_object_stream(0)
- session_id = uuid4()
- session_uri = f"{quote(self._endpoint)}?session_id={session_id.hex}"
+ request_path = scope["path"]
+ match = re.match(r"^/([^/]+(?:/mcp)?)/sse$", request_path)
+ mount_prefix = match.group(1) if match else ""
+ session_uri = f"/{quote(mount_prefix)}{quote(self._endpoint)}?session_id={session_id.hex}"
+
self._read_stream_writers[session_id] = read_stream_writer
logger.debug(f"Created new session with ID: {session_id}")
From 1ac7b63fe648fb2c8bcf87bed0797da79650881e Mon Sep 17 00:00:00 2001
From: sebin1213 <73850629+sebin1213@users.noreply.github.com>
Date: Wed, 9 Apr 2025 11:13:29 +0900
Subject: [PATCH 07/10] Fix generate accurate session_uri for nested SSE paths
---
src/mcp/server/sse.py | 1 +
1 file changed, 1 insertion(+)
diff --git a/src/mcp/server/sse.py b/src/mcp/server/sse.py
index dbb40bed0..a51190376 100644
--- a/src/mcp/server/sse.py
+++ b/src/mcp/server/sse.py
@@ -94,6 +94,7 @@ async def connect_sse(self, scope: Scope, receive: Receive, send: Send):
read_stream_writer, read_stream = anyio.create_memory_object_stream(0)
write_stream, write_stream_reader = anyio.create_memory_object_stream(0)
+ session_id = uuid4()
request_path = scope["path"]
match = re.match(r"^/([^/]+(?:/mcp)?)/sse$", request_path)
mount_prefix = match.group(1) if match else ""
From 7cece5e8e6afeb97eb4e81988acb948a4d512ac5 Mon Sep 17 00:00:00 2001
From: sebin1213 <73850629+sebin1213@users.noreply.github.com>
Date: Wed, 9 Apr 2025 13:15:47 +0900
Subject: [PATCH 08/10] Fix generate accurate session_uri for nested SSE paths
---
src/mcp/server/sse.py | 1 +
1 file changed, 1 insertion(+)
diff --git a/src/mcp/server/sse.py b/src/mcp/server/sse.py
index a51190376..ad6059c3d 100644
--- a/src/mcp/server/sse.py
+++ b/src/mcp/server/sse.py
@@ -37,6 +37,7 @@ async def handle_sse(request):
from urllib.parse import quote
from uuid import UUID, uuid4
+import re
import anyio
from anyio.streams.memory import MemoryObjectReceiveStream, MemoryObjectSendStream
from pydantic import ValidationError
From 3728328497814e046293e5ffc8ac8571968e9e2d Mon Sep 17 00:00:00 2001
From: eyeonyou <example@example.com>
Date: Wed, 9 Apr 2025 22:32:26 +0300
Subject: [PATCH 09/10] style: format to avoid max-line validation error
---
src/mcp/server/sse.py | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/src/mcp/server/sse.py b/src/mcp/server/sse.py
index ad6059c3d..15c90f838 100644
--- a/src/mcp/server/sse.py
+++ b/src/mcp/server/sse.py
@@ -97,9 +97,12 @@ async def connect_sse(self, scope: Scope, receive: Receive, send: Send):
session_id = uuid4()
request_path = scope["path"]
+
match = re.match(r"^/([^/]+(?:/mcp)?)/sse$", request_path)
mount_prefix = match.group(1) if match else ""
- session_uri = f"/{quote(mount_prefix)}{quote(self._endpoint)}?session_id={session_id.hex}"
+
+ session_uri = f"/{quote(mount_prefix)}{quote(self._endpoint)}"
+ session_uri += f"?session_id={session_id.hex}"
self._read_stream_writers[session_id] = read_stream_writer
logger.debug(f"Created new session with ID: {session_id}")
From e1ca588e07e83a8a2178582a48235935861b2f98 Mon Sep 17 00:00:00 2001
From: eyeonyou <example@example.com>
Date: Wed, 9 Apr 2025 22:35:30 +0300
Subject: [PATCH 10/10] style: reorganize imports
---
src/mcp/server/sse.py | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/mcp/server/sse.py b/src/mcp/server/sse.py
index 15c90f838..6ec4c165a 100644
--- a/src/mcp/server/sse.py
+++ b/src/mcp/server/sse.py
@@ -32,12 +32,12 @@ async def handle_sse(request):
"""
import logging
+import re
from contextlib import asynccontextmanager
from typing import Any
from urllib.parse import quote
from uuid import UUID, uuid4
-import re
import anyio
from anyio.streams.memory import MemoryObjectReceiveStream, MemoryObjectSendStream
from pydantic import ValidationError