diff --git a/core/package.json b/core/package.json
index 678f8c0c9..248ea44ab 100644
--- a/core/package.json
+++ b/core/package.json
@@ -8,6 +8,9 @@
     "type": "git",
     "url": "https://github.com/google/adk-js"
   },
+  "engines": {
+    "node": ">=22.12.0"
+  },
   "files": [
     "package.json",
     "README.md",
diff --git a/dev/package.json b/dev/package.json
index 6117df13a..4ecf91085 100644
--- a/dev/package.json
+++ b/dev/package.json
@@ -8,6 +8,9 @@
     "type": "git",
     "url": "https://github.com/google/adk-js"
   },
+  "engines": {
+    "node": ">=22.12.0"
+  },
   "files": [
     "package.json",
     "README.md",
diff --git a/integrations/package.json b/integrations/package.json
index b7c467b4c..3dbc99cb0 100644
--- a/integrations/package.json
+++ b/integrations/package.json
@@ -8,6 +8,9 @@
     "type": "git",
     "url": "https://github.com/google/adk-js"
   },
+  "engines": {
+    "node": ">=22.12.0"
+  },
   "files": [
     "package.json",
     "README.md",
diff --git a/package-lock.json b/package-lock.json
index e29a4a190..658a5a822 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -81,6 +81,9 @@
         "@types/lodash-es": "^4.17.12",
         "openapi-types": "^12.1.3"
       },
+      "engines": {
+        "node": ">=22.12.0"
+      },
       "peerDependencies": {
         "@mikro-orm/mariadb": "^6.6.6",
         "@mikro-orm/mssql": "^6.6.6",
@@ -130,6 +133,9 @@
         "tslib": "^2.6.2",
         "typescript": "^5.9.2",
         "vitest": "^3.2.4"
+      },
+      "engines": {
+        "node": ">=22.12.0"
       }
     },
     "dev/node_modules/@eslint/js": {
@@ -335,6 +341,9 @@
       "license": "Apache-2.0",
       "dependencies": {
         "@google/adk": "^1.5.0"
+      },
+      "engines": {
+        "node": ">=22.12.0"
       }
     },
     "node_modules/@a2a-js/sdk": {
diff --git a/tests/integration/package_manifests/engines_test.ts b/tests/integration/package_manifests/engines_test.ts
new file mode 100644
index 000000000..d503744f0
--- /dev/null
+++ b/tests/integration/package_manifests/engines_test.ts
@@ -0,0 +1,41 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+import {readFile} from 'node:fs/promises';
+import path from 'node:path';
+import {describe, expect, it} from 'vitest';
+
+/**
+ * Workspace directories whose package.json is published to npm. The root
+ * manifest is excluded: it is the workspace container, not a deliverable.
+ */
+const PUBLISHED_WORKSPACES = ['core', 'dev', 'integrations'];
+
+/**
+ * Consumer-facing Node.js floor. 22.12.0 is the lowest release on a supported
+ * LTS line that satisfies every engine constraint in the production dependency
+ * closure. All three published manifests must agree on it.
+ */
+const EXPECTED_NODE_RANGE = '>=22.12.0';
+
+interface Manifest {
+  name?: string;
+  engines?: {node?: string};
+}
+
+async function readManifest(workspace: string): Promise<Manifest> {
+  const manifestPath = path.join(process.cwd(), workspace, 'package.json');
+  return JSON.parse(await readFile(manifestPath, 'utf8')) as Manifest;
+}
+
+describe('published package manifests', () => {
+  it.each(PUBLISHED_WORKSPACES)(
+    '%s declares the shared engines.node range',
+    async (workspace) => {
+      const manifest = await readManifest(workspace);
+      expect(manifest.engines?.node).toBe(EXPECTED_NODE_RANGE);
+    },
+  );
+});