Chore: declare a supported Node.js range (>=20.19.0) and exercise the floor in CI

.github/workflows/cross-language-integration.yml

@@ -16,6 +16,8 @@ jobs:
 
       - name: Use Node.js
         uses: actions/setup-node@v6
+        with:
+          node-version: '24.x'
 
       - name: Setup Go
         uses: actions/setup-go@v5

.github/workflows/validation.yaml

@@ -15,13 +15,23 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
+        node: ['24.x']
+        include:
+          # The exact lower bound of engines.node in core/dev/integrations
+          # package.json. Pinned to the patch so a Node API added later in the
+          # 20.x line cannot pass CI while breaking a consumer who is still
+          # inside the declared range. Keep the two in sync.
+          - os: ubuntu-latest
+            node: '20.19.0'
 
     steps:
       - name: Checkout code
         uses: actions/checkout@v6
 
       - name: Use Node.js
         uses: actions/setup-node@v6
+        with:
+          node-version: ${{ matrix.node }}
 
       - name: Setup Python
         uses: actions/setup-python@v5

core/package.json

@@ -8,6 +8,9 @@
     "type": "git",
     "url": "https://github.com/google/adk-js"
   },
+  "engines": {
+    "node": ">=20.19.0"
+  },
   "files": [
     "package.json",
     "README.md",

dev/package.json

@@ -8,6 +8,9 @@
     "type": "git",
     "url": "https://github.com/google/adk-js"
   },
+  "engines": {
+    "node": ">=20.19.0"
+  },
   "files": [
     "package.json",
     "README.md",

integrations/package.json

@@ -8,6 +8,9 @@
     "type": "git",
     "url": "https://github.com/google/adk-js"
   },
+  "engines": {
+    "node": ">=20.19.0"
+  },
   "files": [
     "package.json",
     "README.md",

tests/integration/package_manifests/engines_test.ts

@@ -0,0 +1,45 @@
+/**
+ * @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 published to npm. The root manifest is the workspace
+ * container, is never published, and deliberately declares no engines: npm
+ * already validates a workspace package's engines during a root install.
+ */
+const PUBLISHED_WORKSPACES = ['core', 'dev', 'integrations'];
+
+interface Manifest {
+  engines?: {node?: string};
+}
+
+async function readEnginesNode(workspace: string): Promise<string | undefined> {
+  const manifestPath = path.join(process.cwd(), workspace, 'package.json');
+  const manifest = JSON.parse(await readFile(manifestPath, 'utf8')) as Manifest;
+  return manifest.engines?.node;
+}
+
+describe('published package manifests', () => {
+  it('declare one agreed engines.node range', async () => {
+    const entries = await Promise.all(
+      PUBLISHED_WORKSPACES.map(
+        async (workspace) =>
+          [workspace, await readEnginesNode(workspace)] as const,
+      ),
+    );
+    const declared = Object.fromEntries(entries);
+    const [reference] = Object.values(declared);
+
+    expect(reference).toBeDefined();
+    expect(declared).toEqual(
+      Object.fromEntries(
+        PUBLISHED_WORKSPACES.map((workspace) => [workspace, reference]),
+      ),
+    );
+  });
+});