diff --git a/packages/extension/CHANGELOG.md b/packages/extension/CHANGELOG.md
index 94f5e927..f157b657 100644
--- a/packages/extension/CHANGELOG.md
+++ b/packages/extension/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## 0.10.1
+
+- "Customize Template" now opens the created `template.json` after
+  success, instead of only showing a notification and silently
+  refreshing the tree — found via live testing: the tree refresh alone
+  gave no visible feedback unless "Project" was already expanded.
+
 ## 0.10.0
 
 - Added "Delete Project Template" to the Templates view, scoped to
diff --git a/packages/extension/package.json b/packages/extension/package.json
index 7abe3bd2..14391a49 100644
--- a/packages/extension/package.json
+++ b/packages/extension/package.json
@@ -3,7 +3,7 @@
   "displayName": "OpenSpec Workbench",
   "description": "Native OpenSpec workflow with lifecycle controls, VS Code Chat, persistent processes, checkpoints, and conflict-safe rollback.",
   "publisher": "openspec-ui",
-  "version": "0.10.0",
+  "version": "0.10.1",
   "icon": "media/icon.png",
   "license": "MIT",
   "repository": {
diff --git a/packages/extension/src/commands.test.ts b/packages/extension/src/commands.test.ts
index 227ecdfa..3a177cfe 100644
--- a/packages/extension/src/commands.test.ts
+++ b/packages/extension/src/commands.test.ts
@@ -383,7 +383,7 @@ describe("registerCommands", () => {
       },
     };
 
-    it("customizes a built-in template and refreshes the templates tree", async () => {
+    it("customizes a built-in template, refreshes the templates tree, and opens the created manifest", async () => {
       customizeTemplateMock.mockResolvedValue({});
       const deps = makeDeps();
       registerCommands(makeContext() as unknown as import("vscode").ExtensionContext, deps);
@@ -392,6 +392,9 @@ describe("registerCommands", () => {
 
       expect(customizeTemplateMock).toHaveBeenCalledWith("/workspace/repo", "seed");
       expect(deps.refreshTemplatesTree).toHaveBeenCalled();
+      const manifestPath = path.join("/workspace/repo", "openspec", "templates", "seed", "template.json");
+      expect(vscodeMock.workspace.openTextDocument).toHaveBeenCalledWith(expect.objectContaining({ fsPath: manifestPath }));
+      expect(vscodeMock.window.showTextDocument).toHaveBeenCalled();
     });
 
     it("reports an already-customized template as a warning, not an error", async () => {
diff --git a/packages/extension/src/commands.ts b/packages/extension/src/commands.ts
index 0a8e6313..a1650f40 100644
--- a/packages/extension/src/commands.ts
+++ b/packages/extension/src/commands.ts
@@ -340,6 +340,15 @@ export function registerCommands(context: vscode.ExtensionContext, deps: Command
       try {
         await customizeTemplate(workspaceRoot, item.template.manifest.id);
         deps.refreshTemplatesTree();
+        // Open the created manifest as visible proof — a toast notification
+        // alone is easy to miss/dismiss, and the tree refresh isn't visible
+        // unless "Project" happens to already be expanded (found via live
+        // testing: the command silently succeeds with no other feedback).
+        const manifestUri = vscode.Uri.file(
+          path.join(workspaceRoot, "openspec", "templates", item.template.manifest.id, "template.json"),
+        );
+        const manifestDocument = await vscode.workspace.openTextDocument(manifestUri);
+        await vscode.window.showTextDocument(manifestDocument, { preview: false });
         void vscode.window.showInformationMessage(`OpenSpec UI: customized "${item.template.manifest.title}".`);
       } catch (error) {
         if (error instanceof TemplateAlreadyExistsError) {