diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..5b4d969
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+node_modules/
+.pulse/
+dist/
diff --git a/bun.lock b/bun.lock
new file mode 100644
index 0000000..fb7cecf
--- /dev/null
+++ b/bun.lock
@@ -0,0 +1,35 @@
+{
+  "lockfileVersion": 1,
+  "configVersion": 1,
+  "workspaces": {
+    "": {
+      "name": "@upulse/engine",
+      "dependencies": {
+        "@uncaged/pulse": "file:../../repos/pulse/packages/pulse",
+      },
+      "devDependencies": {
+        "@types/bun": "^1.2.0",
+        "typescript": "^5.8.0",
+      },
+    },
+  },
+  "packages": {
+    "@types/bun": ["@types/bun@1.3.12", "", { "dependencies": { "bun-types": "1.3.12" } }, "sha512-DBv81elK+/VSwXHDlnH3Qduw+KxkTIWi7TXkAeh24zpi5l0B2kUg9Ga3tb4nJaPcOFswflgi/yAvMVBPrxMB+A=="],
+
+    "@types/node": ["@types/node@25.6.0", "", { "dependencies": { "undici-types": "~7.19.0" } }, "sha512-+qIYRKdNYJwY3vRCZMdJbPLJAtGjQBudzZzdzwQYkEPQd+PJGixUL5QfvCLDaULoLv+RhT3LDkwEfKaAkgSmNQ=="],
+
+    "@uncaged/pulse": ["@uncaged/pulse@file:../../repos/pulse/packages/pulse", { "dependencies": { "jsonata": "^2.1.0", "zod": "^4.3.6" }, "devDependencies": { "@types/node": "^25.6.0", "bun-types": "latest", "typescript": "^6.0.2" } }],
+
+    "bun-types": ["bun-types@1.3.12", "", { "dependencies": { "@types/node": "*" } }, "sha512-HqOLj5PoFajAQciOMRiIZGNoKxDJSr6qigAttOX40vJuSp6DN/CxWp9s3C1Xwm4oH7ybueITwiaOcWXoYVoRkA=="],
+
+    "jsonata": ["jsonata@2.1.0", "", {}, "sha512-OCzaRMK8HobtX8fp37uIVmL8CY1IGc/a6gLsDqz3quExFR09/U78HUzWYr7T31UEB6+Eu0/8dkVD5fFDOl9a8w=="],
+
+    "typescript": ["typescript@5.9.3", "", { "bin": { "tsc": "bin/tsc", "tsserver": "bin/tsserver" } }, "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw=="],
+
+    "undici-types": ["undici-types@7.19.2", "", {}, "sha512-qYVnV5OEm2AW8cJMCpdV20CDyaN3g0AjDlOGf1OW4iaDEx8MwdtChUp4zu4H0VP3nDRF/8RKWH+IPp9uW0YGZg=="],
+
+    "zod": ["zod@4.3.6", "", {}, "sha512-rftlrkhHZOcjDwkGlnUtZZkvaPHCsDATp4pGpuOOMDaTdDDXF91wuVDJoWoPsKX/3YPQ5fHuF3STjcYyKr+Qhg=="],
+
+    "@uncaged/pulse/typescript": ["typescript@6.0.3", "", { "bin": { "tsc": "bin/tsc", "tsserver": "bin/tsserver" } }, "sha512-y2TvuxSZPDyQakkFRPZHKFm+KKVqIisdg9/CZwm9ftvKXLP8NRWj38/ODjNbr43SsoXqNuAisEf1GdCxqWcdBw=="],
+  }
+}
diff --git a/package.json b/package.json
index 52a401d..b79038b 100644
--- a/package.json
+++ b/package.json
@@ -7,7 +7,7 @@
     "test": "bun test"
   },
   "dependencies": {
-    "@uncaged/pulse": "workspace:*"
+    "@uncaged/pulse": "file:../../repos/pulse/packages/pulse"
   },
   "devDependencies": {
     "typescript": "^5.8.0",
diff --git a/src/workflows/.gitkeep b/src/workflows/.gitkeep
deleted file mode 100644
index e69de29..0000000
diff --git a/src/workflows/ping-pong.test.ts b/src/workflows/ping-pong.test.ts
new file mode 100644
index 0000000..a1a418c
--- /dev/null
+++ b/src/workflows/ping-pong.test.ts
@@ -0,0 +1,49 @@
+/**
+ * ping-pong workflow test — validates engine can run workflows.
+ *
+ * 小橘 🍊 (NEKO Team)
+ */
+
+import { afterEach, describe, expect, it } from 'bun:test';
+import { mkdtempSync, rmSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { createStore, createWorkflowRule } from '@uncaged/pulse';
+import { pingPong } from './ping-pong.js';
+
+describe('ping-pong workflow', () => {
+  let tmpDir: string;
+
+  afterEach(() => {
+    if (tmpDir) rmSync(tmpDir, { recursive: true, force: true });
+  });
+
+  it('START → pong → END', async () => {
+    tmpDir = mkdtempSync(join(tmpdir(), 'engine-test-'));
+    const store = createStore({
+      eventsDbPath: join(tmpDir, 'test.db'),
+      objectsDir: join(tmpDir, 'objects'),
+    });
+
+    const rule = createWorkflowRule(pingPong, store);
+
+    // Trigger
+    const hash = store.putObject('ping');
+    store.appendEvent({
+      occurredAt: Date.now(),
+      kind: 'ping-pong.__start__',
+      key: 't1',
+      hash,
+    });
+
+    const r1 = await rule.tick();
+    expect(r1.executed).toMatchObject([{ topicId: 't1', role: 'pong' }]);
+    expect(r1.executed[0].content).toBe('pong: ping');
+
+    // No more work
+    const r2 = await rule.tick();
+    expect(r2.executed).toEqual([]);
+
+    store.close();
+  });
+});
diff --git a/src/workflows/ping-pong.ts b/src/workflows/ping-pong.ts
new file mode 100644
index 0000000..0aeca36
--- /dev/null
+++ b/src/workflows/ping-pong.ts
@@ -0,0 +1,28 @@
+/**
+ * Example: ping-pong workflow — validates engine setup.
+ *
+ * 小橘 🍊 (NEKO Team)
+ */
+
+import { END, START, type Role, type WorkflowType } from '@uncaged/pulse/src/workflows/workflow-type.js';
+
+type PingPongRoles = {
+  pong: Role<{ echo: true }>;
+};
+
+export const pingPong: WorkflowType<PingPongRoles> = {
+  name: 'ping-pong',
+  roles: {
+    pong: async (chain) => {
+      const start = chain.find((m) => m.role === '__start__');
+      return {
+        content: `pong: ${start?.content ?? ''}`,
+        meta: { echo: true as const },
+      };
+    },
+  },
+  moderator: (output) => {
+    if (output.role === START) return 'pong';
+    return END;
+  },
+};