diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index eec3a8d..f5c0fb6 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -576,6 +576,9 @@ importers:
 
   packages/core-realtime:
     dependencies:
+      '@repo/core-shared':
+        specifier: workspace:*
+        version: link:../core-shared
       payload:
         specifier: ^3.0.0
         version: 3.81.0(graphql@16.13.2)(typescript@5.9.3)
@@ -957,6 +960,12 @@ importers:
         specifier: ^3.1.0
         version: 3.2.4(@types/debug@4.1.13)(@types/node@22.19.17)(happy-dom@20.8.9)(jiti@2.6.1)(jsdom@25.0.1)(lightningcss@1.32.0)(sass@1.99.0)(terser@5.46.2)(tsx@4.21.0)
 
+  turbo/generators:
+    devDependencies:
+      vitest:
+        specifier: ^3.1.0
+        version: 3.2.4(@types/debug@4.1.13)(@types/node@25.5.2)(happy-dom@20.8.9)(jiti@2.6.1)(jsdom@25.0.1)(lightningcss@1.32.0)(sass@1.99.0)(terser@5.46.2)(tsx@4.21.0)
+
 packages:
 
   '@adobe/css-tools@4.4.4':
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index 3ff5faa..6e4d6f7 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -1,3 +1,4 @@
 packages:
   - "apps/*"
   - "packages/*"
+  - "turbo/generators"
diff --git a/turbo/generators/config.test.ts b/turbo/generators/config.test.ts
new file mode 100644
index 0000000..e87ffd3
--- /dev/null
+++ b/turbo/generators/config.test.ts
@@ -0,0 +1,20 @@
+import { describe, it, expect } from "vitest";
+import type { PlopTypes } from "@turbo/gen";
+import generator from "./config";
+
+describe("core-package generator", () => {
+  it("is registered with an empty choices list initially", () => {
+    const captured: Array<{ name: string; def: PlopTypes.PlopGeneratorConfig }> = [];
+    const plopMock = {
+      setHelper: () => {},
+      setGenerator: (name: string, def: PlopTypes.PlopGeneratorConfig) =>
+        captured.push({ name, def }),
+    } as unknown as PlopTypes.NodePlopAPI;
+    generator(plopMock);
+    const corePkg = captured.find((c) => c.name === "core-package");
+    expect(corePkg).toBeDefined();
+    const prompts = corePkg!.def.prompts as Array<{ name: string; choices: unknown[] }>;
+    expect(prompts[0]!.name).toBe("name");
+    expect(prompts[0]!.choices).toEqual([]);
+  });
+});
diff --git a/turbo/generators/config.ts b/turbo/generators/config.ts
index 677911c..3a4d8e3 100644
--- a/turbo/generators/config.ts
+++ b/turbo/generators/config.ts
@@ -491,6 +491,38 @@ export default function generator(plop: PlopTypes.NodePlopAPI): void {
     },
   });
 
+  /**
+   * Turbo generator: `core-package`
+   *
+   * Scaffolds an optional core package back into a slimmed template. Each
+   * name maps to a verbatim snapshot of the package captured at generator-add
+   * time. Phases 3-6 each register one entry in CORE_PACKAGE_GENERATORS.
+   */
+  const CORE_PACKAGE_GENERATORS: Record<string, () => PlopTypes.ActionType[]> =
+    {
+      // Phases 3-6 each insert one entry here.
+    };
+
+  plop.setGenerator("core-package", {
+    description: "Scaffold an optional core package (realtime, events, trpc, ui)",
+    prompts: [
+      {
+        type: "list",
+        name: "name",
+        message: "Which optional core package?",
+        choices: [],
+      },
+    ],
+    actions: (answers) => {
+      const a = answers as { name: string };
+      const handler = CORE_PACKAGE_GENERATORS[a.name];
+      if (!handler) {
+        throw new Error(`No generator for core-package '${a.name}'`);
+      }
+      return handler();
+    },
+  });
+
   /**
    * Turbo generator: `job`
    *
diff --git a/turbo/generators/package.json b/turbo/generators/package.json
index 9b4bb97..dfc8cd7 100644
--- a/turbo/generators/package.json
+++ b/turbo/generators/package.json
@@ -2,5 +2,11 @@
   "name": "@repo/turbo-generators",
   "private": true,
   "version": "0.0.0",
-  "type": "module"
+  "type": "module",
+  "scripts": {
+    "test": "vitest run"
+  },
+  "devDependencies": {
+    "vitest": "^3.1.0"
+  }
 }
diff --git a/turbo/generators/vitest.config.ts b/turbo/generators/vitest.config.ts
new file mode 100644
index 0000000..a5d041f
--- /dev/null
+++ b/turbo/generators/vitest.config.ts
@@ -0,0 +1,11 @@
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+  test: {
+    globals: true,
+    environment: "node",
+    include: ["*.test.ts", "lib/*.test.ts"],
+    clearMocks: true,
+    restoreMocks: true,
+  },
+});