From dcaeef0f3dd6661216697531d5fd60d7b90bcdc4 Mon Sep 17 00:00:00 2001
From: Jeremiah Lowin <153965+jlowin@users.noreply.github.com>
Date: Sat, 7 Mar 2026 11:40:57 -0500
Subject: [PATCH] =?UTF-8?q?Handle=20missing=20npx.cmd=20fallback=20on=20Wi?=
 =?UTF-8?q?ndows=20=F0=9F=A4=96=20Generated=20with=20GPT-5.2-Codex=20(#341?=
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---
 src/fastmcp/cli/cli.py |  2 +-
 tests/cli/test_cli.py  | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/fastmcp/cli/cli.py b/src/fastmcp/cli/cli.py
index f6472c470..68a4a4da0 100644
--- a/src/fastmcp/cli/cli.py
+++ b/src/fastmcp/cli/cli.py
@@ -54,7 +54,7 @@ def _get_npx_command():
             try:
                 subprocess.run([cmd, "--version"], check=True, capture_output=True)
                 return cmd
-            except subprocess.CalledProcessError:
+            except (subprocess.CalledProcessError, FileNotFoundError):
                 continue
         return None
     return "npx"  # On Unix-like systems, just use npx
diff --git a/tests/cli/test_cli.py b/tests/cli/test_cli.py
index eecc4300c..f7b9e47a8 100644
--- a/tests/cli/test_cli.py
+++ b/tests/cli/test_cli.py
@@ -440,6 +440,23 @@ class TestWindowsSpecific:
             assert result == "npx.exe"
             assert mock_run.call_count == 2
 
+    @patch("subprocess.run")
+    def test_get_npx_command_windows_cmd_missing(self, mock_run):
+        """Test npx command detection continues when npx.cmd is missing."""
+        from fastmcp.cli.cli import _get_npx_command
+
+        with patch("sys.platform", "win32"):
+            # Missing npx.cmd should not abort detection
+            mock_run.side_effect = [
+                FileNotFoundError("npx.cmd not found"),
+                Mock(returncode=0),
+            ]
+
+            result = _get_npx_command()
+
+            assert result == "npx.exe"
+            assert mock_run.call_count == 2
+
     @patch("subprocess.run")
     def test_get_npx_command_windows_fallback(self, mock_run):
         """Test npx command detection on Windows with plain npx."""