From 422267e227db6f7c841e4aa90e0e372de4bd6522 Mon Sep 17 00:00:00 2001
From: Alex <alex@maximum.guru>
Date: Thu, 20 Mar 2025 18:43:45 +0000
Subject: [PATCH] Fixed issue #326 - MCP client with npx not working when env
 parameter of StdioServerParameters is set

---
 src/mcp/client/stdio.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/mcp/client/stdio.py b/src/mcp/client/stdio.py
index ac8ae7e70..df721bbc3 100644
--- a/src/mcp/client/stdio.py
+++ b/src/mcp/client/stdio.py
@@ -103,7 +103,11 @@ async def stdio_client(server: StdioServerParameters, errlog: TextIO = sys.stder
 
     process = await anyio.open_process(
         [server.command, *server.args],
-        env=server.env if server.env is not None else get_default_environment(),
+        env=(
+            {**get_default_environment(), **server.env}
+            if server.env is not None
+            else get_default_environment()
+        ),
         stderr=errlog,
         cwd=server.cwd,
     )