Add util for windows sub-process

src/specify_cli/integrations/copilot/__init__.py

@@ -24,6 +24,16 @@
 from ..manifest import IntegrationManifest
 
 
+def _copilot_executable() -> str:
+    """Return the executable name for Copilot CLI on this platform.
+
+    On Windows, subprocess invocation is reliable with `copilot.cmd`.
+    """
+    if os.name == "nt":
+        return "copilot.cmd"
+    return "copilot"
+
+
 def _allow_all() -> bool:
     """Return True if the Copilot CLI should run with full permissions.
 
@@ -138,7 +148,7 @@ def build_exec_args(
         # Controlled by SPECKIT_COPILOT_ALLOW_ALL_TOOLS env var
         # (default: enabled).  The deprecated SPECKIT_ALLOW_ALL_TOOLS
         # is also honoured as a fallback.
-        args = ["copilot", "-p", prompt]
+        args = [_copilot_executable(), "-p", prompt]
         if _allow_all():
             args.append("--yolo")
         if model:
@@ -206,7 +216,7 @@ def dispatch_command(
             agent_name = f"speckit.{stem}"
             prompt = args or ""
 
-        cli_args = ["copilot", "-p", prompt]
+        cli_args = [_copilot_executable(), "-p", prompt]
         if not skills_mode:
             cli_args.extend(["--agent", agent_name])
         if _allow_all():

tests/test_workflows.py

@@ -13,6 +13,7 @@
 from __future__ import annotations
 
 import json
+import os
 import shutil
 import tempfile
 from pathlib import Path
@@ -373,7 +374,8 @@ def test_copilot_exec_args(self, monkeypatch):
         from specify_cli.integrations.copilot import CopilotIntegration
         impl = CopilotIntegration()
         args = impl.build_exec_args("do stuff", model="claude-sonnet-4-20250514")
-        assert args[0] == "copilot"
+        expected_exec = "copilot.cmd" if os.name == "nt" else "copilot"
+        assert args[0] == expected_exec
         assert "-p" in args
         assert "--yolo" in args
         assert "--model" in args