fix: write Codex dev skills as files

src/specify_cli/agents.py

@@ -733,7 +733,7 @@ def _write_registered_output(
         link_outputs: bool,
     ) -> None:
         """Write a rendered agent artifact, optionally as a dev-mode symlink."""
-        if not link_outputs:
+        if not link_outputs or (agent_name == "codex" and extension == "/SKILL.md"):
             dest_file.write_text(content, encoding="utf-8")
             return
 

src/specify_cli/extensions.py

@@ -1012,13 +1012,14 @@ def _register_extension_skills(
             skill_file = skill_subdir / "SKILL.md"
             cache_root = extension_dir / ".specify-dev" / "extension-skills"
             cache_file = cache_root / skill_name / "SKILL.md"
+            use_dev_symlink = link_outputs and selected_ai != "codex"
             CommandRegistrar._ensure_inside(cache_file, cache_root)
             if skill_file.exists() or skill_file.is_symlink():
                 # Do not overwrite user-customized skills, but allow dev-mode
                 # symlinks that point back to this extension's generated cache
                 # to be refreshed on a subsequent dev install.
                 if not (
-                    link_outputs
+                    use_dev_symlink
                     and self._is_expected_dev_symlink(skill_file, cache_file)
                 ):
                     continue
@@ -1089,7 +1090,7 @@ def _register_extension_skills(
                     skill_content
                 )
 
-            if link_outputs:
+            if use_dev_symlink:
                 try:
                     cache_file.parent.mkdir(parents=True, exist_ok=True)
                     cache_file.write_text(skill_content, encoding="utf-8")

tests/test_extensions.py

@@ -4619,6 +4619,42 @@ def test_add_dev_links_copilot_agent_when_supported(
         else:
             assert not agent_file.is_symlink()
 
+    def test_add_dev_writes_codex_skills_as_files(self, extension_dir, project_dir):
+        """Codex dev skills should be written as files so Codex can load them."""
+        from typer.testing import CliRunner
+        from unittest.mock import patch
+        from specify_cli import app
+
+        init_options = project_dir / ".specify" / "init-options.json"
+        init_options.write_text(
+            json.dumps({"ai": "codex", "ai_skills": True}), encoding="utf-8"
+        )
+
+        runner = CliRunner()
+        with patch.object(Path, "cwd", return_value=project_dir):
+            result = runner.invoke(
+                app,
+                ["extension", "add", str(extension_dir), "--dev"],
+                catch_exceptions=True,
+            )
+
+        assert result.exit_code == 0, result.output
+
+        skill_file = (
+            project_dir
+            / ".agents"
+            / "skills"
+            / "speckit-test-ext-hello"
+            / "SKILL.md"
+        )
+        assert skill_file.exists()
+        assert not skill_file.is_symlink()
+
+        content = skill_file.read_text(encoding="utf-8")
+        assert "name: speckit-test-ext-hello" in content
+        assert "metadata:" in content
+        assert "source: test-ext:commands/hello.md" in content
+
     def test_add_dev_falls_back_to_copy_when_windows_symlinks_unavailable(
         self, extension_dir, project_dir, monkeypatch
     ):