From e381261026e4b0a8b9253a5b40b21aada7543fa3 Mon Sep 17 00:00:00 2001
From: kongqi <32472226+kongqi404@users.noreply.github.com>
Date: Wed, 16 Apr 2025 13:24:30 +0000
Subject: [PATCH 1/2] Add npx validation

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

diff --git a/src/fastmcp/client/transports.py b/src/fastmcp/client/transports.py
index 27b885688..c3c2b797b 100644
--- a/src/fastmcp/client/transports.py
+++ b/src/fastmcp/client/transports.py
@@ -7,7 +7,7 @@ from pathlib import Path
 from typing import (
     TypedDict,
 )
-
+import shutil
 from mcp import ClientSession, StdioServerParameters
 from mcp.client.session import (
     ListRootsFnT,
@@ -341,6 +341,10 @@ class NpxStdioTransport(StdioTransport):
             env_vars: Additional environment variables
             use_package_lock: Whether to use package-lock.json (--prefer-offline)
         """
+        # verify npx is installed
+        if shutil.which("npx") is None:
+            raise ValueError("Command 'npx' not found")
+
         # Basic validation
         if project_directory and not Path(project_directory).exists():
             raise NotADirectoryError(

From b4c53c9f883deb58d0b298b3a11c8b15d9ec5a8f Mon Sep 17 00:00:00 2001
From: Jeremiah Lowin <153965+jlowin@users.noreply.github.com>
Date: Wed, 16 Apr 2025 09:34:59 -0400
Subject: [PATCH 2/2] Fix static checks

---
 src/fastmcp/client/transports.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/fastmcp/client/transports.py b/src/fastmcp/client/transports.py
index c3c2b797b..cea14a0b9 100644
--- a/src/fastmcp/client/transports.py
+++ b/src/fastmcp/client/transports.py
@@ -2,12 +2,13 @@ import abc
 import contextlib
 import datetime
 import os
+import shutil
 from collections.abc import AsyncIterator
 from pathlib import Path
 from typing import (
     TypedDict,
 )
-import shutil
+
 from mcp import ClientSession, StdioServerParameters
 from mcp.client.session import (
     ListRootsFnT,