Display deprication warning during git extension setup

Author: Aaron Sun

extensions/git/extension.yml

@@ -8,6 +8,13 @@ extension:
   author: spec-kit-core
   repository: https://github.com/github/spec-kit
   license: MIT
+  install_notice: |
+    The git extension is currently enabled by default, but starting with
+    v1.0.0 it will require explicit opt-in.
+
+    To opt in after v1.0.0:
+      • specify init --extension git
+      • specify extension add git  (post-init)
 
 requires:
   speckit_version: ">=0.2.0"

src/specify_cli/__init__.py

@@ -1278,6 +1278,7 @@ def init(
             ensure_constitution_from_template(project_path, tracker=tracker)
 
             _git_ext_freshly_installed = False
+            _git_ext_install_notice: str | None = None
             if not no_git:
                 tracker.start("git")
                 git_messages = []
@@ -1308,11 +1309,12 @@ def init(
                         if manager.registry.is_installed("git"):
                             git_messages.append("extension already installed")
                         else:
-                            manager.install_from_directory(
+                            ext_manifest = manager.install_from_directory(
                                 bundled_path, get_speckit_version()
                             )
                             git_messages.append("extension installed")
                             _git_ext_freshly_installed = True
+                            _git_ext_install_notice = ext_manifest.install_notice
                     else:
                         git_has_error = True
                         git_messages.append("bundled extension not found")
@@ -1456,16 +1458,12 @@ def init(
     console.print(tracker.render())
     console.print("\n[bold green]Project ready.[/bold green]")
 
-    if _git_ext_freshly_installed:
+    if _git_ext_freshly_installed and _git_ext_install_notice:
         console.print()
         console.print(
             Panel(
-                "The [bold]git[/bold] extension is currently enabled by default, "
-                "but starting with [bold]v1.0.0[/bold] it will require explicit opt-in.\n\n"
-                "To opt in after v1.0.0:\n"
-                "  • [cyan]specify init --extension git[/cyan]\n"
-                "  • [cyan]specify extension add git[/cyan]  (post-init)",
-                title="[yellow]⚠ Upcoming Change: git Extension[/yellow]",
+                _git_ext_install_notice.strip(),
+                title="[yellow]⚠ Deprecation notice: git Extension[/yellow]",
                 border_style="yellow",
                 padding=(1, 2),
             )

src/specify_cli/extensions.py

@@ -346,6 +346,15 @@ def hooks(self) -> Dict[str, Any]:
         """Get hook definitions."""
         return self.data.get("hooks", {})
 
+    @property
+    def install_notice(self) -> str | None:
+        """Get optional install notice message.
+
+        Extensions can specify an 'install_notice' field to display
+        important information to users when the extension is first installed.
+        """
+        return self.data.get("extension", {}).get("install_notice")
+
     def get_hash(self) -> str:
         """Calculate SHA256 hash of manifest file."""
         with open(self.path, 'rb') as f:

tests/extensions/git/test_git_extension.py

@@ -800,7 +800,7 @@ def test_check_feature_branch_rejects_malformed_timestamp(self, tmp_path: Path):
             capture_output=True, text=True,
         )
         assert result.returncode != 0
-        
+
     def test_check_feature_branch_accepts_single_prefix(self, tmp_path: Path):
         """git-common check_feature_branch matches core: one optional path prefix."""
         project = _setup_project(tmp_path)
@@ -854,11 +854,21 @@ def test_deprecation_notice_shown_on_fresh_install(self, tmp_path: Path):
         project_dir = tmp_path / "test-project"
         runner = CliRunner()
 
+        mock_manifest = MagicMock()
+        mock_manifest.install_notice = (
+            "The git extension is currently enabled by default, but starting with\n"
+            "v1.0.0 it will require explicit opt-in.\n\n"
+            "To opt in after v1.0.0:\n"
+            "  • specify init --extension git\n"
+            "  • specify extension add git  (post-init)"
+        )
+
         mock_registry = MagicMock()
         mock_registry.is_installed.return_value = False
 
         mock_manager = MagicMock()
         mock_manager.registry = mock_registry
+        mock_manager.install_from_directory.return_value = mock_manifest
 
         with patch("specify_cli.extensions.ExtensionManager", return_value=mock_manager):
             result = runner.invoke(
@@ -868,9 +878,9 @@ def test_deprecation_notice_shown_on_fresh_install(self, tmp_path: Path):
             )
 
         assert result.exit_code == 0, result.output
-        assert "Upcoming Change: git Extension" in result.output
+        assert "Deprecation notice: git Extension" in result.output
         assert "v1.0.0" in result.output
-        assert "specify init --extension git" in result.output
+        assert "specify extension add git" in result.output
 
     def test_deprecation_notice_not_shown_when_already_installed(self, tmp_path: Path):
         """specify init does NOT show the deprecation notice when git extension is already installed."""
@@ -895,7 +905,7 @@ def test_deprecation_notice_not_shown_when_already_installed(self, tmp_path: Pat
             )
 
         assert result.exit_code == 0, result.output
-        assert "Upcoming Change: git Extension" not in result.output
+        assert "Deprecation notice: git Extension" not in result.output
 
     def test_deprecation_notice_not_shown_with_no_git_flag(self, tmp_path: Path):
         """specify init does NOT show the deprecation notice when --no-git is passed."""
@@ -912,4 +922,33 @@ def test_deprecation_notice_not_shown_with_no_git_flag(self, tmp_path: Path):
         )
 
         assert result.exit_code == 0, result.output
-        assert "Upcoming Change: git Extension" not in result.output
+        assert "Deprecation notice: git Extension" not in result.output
+
+    def test_deprecation_notice_not_shown_when_no_install_notice(self, tmp_path: Path):
+        """specify init does NOT show the deprecation notice if extension has no install_notice."""
+        from typer.testing import CliRunner
+        from unittest.mock import patch, MagicMock
+        from specify_cli import app
+
+        project_dir = tmp_path / "test-project"
+        runner = CliRunner()
+
+        mock_manifest = MagicMock()
+        mock_manifest.install_notice = None  # No notice defined
+
+        mock_registry = MagicMock()
+        mock_registry.is_installed.return_value = False
+
+        mock_manager = MagicMock()
+        mock_manager.registry = mock_registry
+        mock_manager.install_from_directory.return_value = mock_manifest
+
+        with patch("specify_cli.extensions.ExtensionManager", return_value=mock_manager):
+            result = runner.invoke(
+                app,
+                ["init", str(project_dir), "--ai", "claude", "--ignore-agent-tools", "--script", "sh"],
+                catch_exceptions=False,
+            )
+
+        assert result.exit_code == 0, result.output
+        assert "Deprecation notice: git Extension" not in result.output