Fix: keep Node built-ins out of the @google/adk browser entry graph

core/build.js

@@ -63,7 +63,7 @@ function build({
 
   if (bundle) {
     buildOptions.entryPoints = [`./src/${entry}`];
-    buildOptions.outfile = `./dist/${targetDir}/index.js`;
+    buildOptions.outfile = `./dist/${targetDir}/${entry.replace(/\.ts$/, '.js')}`;
   } else {
     buildOptions.entryPoints = ['./src/**/*.ts'];
     buildOptions.outdir = `./dist/${targetDir}`;
@@ -101,12 +101,15 @@ async function main() {
     await Promise.all([
       build({targetDir: 'esm', platform: 'node', format: 'esm', bundle}),
       build({targetDir: 'cjs', platform: 'node', format: 'cjs', bundle}),
+      // esbuild rejects `alias` without `bundle`, so the browser shims only
+      // reach a bundled web output. `prepublishOnly` runs the non-bundled
+      // `npm run build`, so the web target ignores the flag and always bundles.
       build({
         targetDir: 'web',
         platform: 'browser',
         format: 'esm',
         entry: 'index_web.ts',
-        bundle,
+        bundle: true,
       }),
     ]);
 

core/src/common.ts

@@ -260,8 +260,6 @@ export {
   LoadArtifactsTool,
 } from './tools/load_artifacts_tool.js';
 export {LOAD_MEMORY, LoadMemoryTool} from './tools/load_memory_tool.js';
-export {LOAD_WEB_PAGE, loadWebPage} from './tools/load_web_page.js';
-export type {LoadWebPageOptions} from './tools/load_web_page.js';
 export {LongRunningFunctionTool} from './tools/long_running_tool.js';
 export {
   PRELOAD_MEMORY,
@@ -289,21 +287,8 @@ export type {TaskExecutable} from './utils/task.js';
 export {GoogleLLMVariant} from './utils/variant_utils.js';
 export {version} from './version.js';
 
-export {GCPSkillRegistry} from './skills/gcp_skill_registry.js';
-export type {GCPSkillRegistryOptions} from './skills/gcp_skill_registry.js';
-export {
-  loadAllSkillsInDir,
-  loadSkillFromDir,
-  loadSkillFromZipBuffer,
-  validateSkillDir,
-} from './skills/loader.js';
 export type {Frontmatter, Resources, Script, Skill} from './skills/skill.js';
 export type {SkillRegistry} from './skills/skill_registry.js';
-export {ListSkillsTool} from './tools/skill/list_skills_tool.js';
-export {LoadSkillResourceTool} from './tools/skill/load_skill_resource_tool.js';
-export {LoadSkillTool} from './tools/skill/load_skill_tool.js';
-export {SearchSkillsTool} from './tools/skill/search_skills_tool.js';
-export {SkillToolset} from './tools/skill/skill_toolset.js';
 
 export * from './artifacts/base_artifact_service.js';
 export * from './features/feature_registry.js';

core/src/index.ts

@@ -45,16 +45,26 @@ export type {
   VertexAiCreateSessionRequest,
   VertexAiSessionServiceOptions,
 } from './sessions/vertex_ai_session_service.js';
+export {GCPSkillRegistry} from './skills/gcp_skill_registry.js';
+export type {GCPSkillRegistryOptions} from './skills/gcp_skill_registry.js';
 export {
   loadAllSkillsInDir,
   loadSkillFromDir,
+  loadSkillFromZipBuffer,
   validateSkillDir,
 } from './skills/loader.js';
+export {LOAD_WEB_PAGE, loadWebPage} from './tools/load_web_page.js';
+export type {LoadWebPageOptions} from './tools/load_web_page.js';
+export {ListSkillsTool} from './tools/skill/list_skills_tool.js';
+export {LoadSkillResourceTool} from './tools/skill/load_skill_resource_tool.js';
+export {LoadSkillTool} from './tools/skill/load_skill_tool.js';
 export {
   RunSkillInlineScriptErrorCode,
   RunSkillInlineScriptTool,
 } from './tools/skill/run_skill_inline_script_tool.js';
 export {RunSkillScriptTool} from './tools/skill/run_skill_script_tool.js';
+export {SearchSkillsTool} from './tools/skill/search_skills_tool.js';
+export {SkillToolset} from './tools/skill/skill_toolset.js';
 
 export * from './integrations/agent_registry/agent_registry.js';
 export * from './telemetry/google_cloud.js';

core/test/index_web_test.ts

@@ -0,0 +1,97 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as adk from '@google/adk';
+import esbuild from 'esbuild';
+import {isBuiltin} from 'node:module';
+import {fileURLToPath} from 'node:url';
+import {describe, expect, it} from 'vitest';
+import * as web from '../src/index_web.js';
+
+/**
+ * The Node built-ins the browser build is allowed to reach, because
+ * `buildOptions.alias` in `core/build.js` swaps each one for a browser
+ * implementation. Keep this set in step with that alias table.
+ *
+ * The `import {createRequire} from 'module'` banner is excluded on purpose: it
+ * is injected after the module graph is resolved, so it never appears in the
+ * metafile, and removing it from the browser build is separately queued work.
+ */
+const ALIASED_NODE_BUILTINS = new Set(['node:async_hooks']);
+
+/** Symbols that are Node-only and must not reach the browser entry point. */
+const NODE_ONLY_EXPORTS = [
+  'LOAD_WEB_PAGE',
+  'loadWebPage',
+  'GCPSkillRegistry',
+  'loadAllSkillsInDir',
+  'loadSkillFromDir',
+  'loadSkillFromZipBuffer',
+  'validateSkillDir',
+  'ListSkillsTool',
+  'LoadSkillResourceTool',
+  'LoadSkillTool',
+  'SearchSkillsTool',
+  'SkillToolset',
+] as const;
+
+const coreDir = fileURLToPath(new URL('..', import.meta.url));
+
+/** Budget (ms) for the bundle below: it walks the whole browser export graph. */
+const BUNDLE_TIMEOUT_MS = 30000;
+
+describe('browser entry point', () => {
+  it(
+    'reaches no Node built-in the browser build does not alias',
+    async () => {
+      const result = await esbuild.build({
+        absWorkingDir: coreDir,
+        entryPoints: ['./src/index_web.ts'],
+        platform: 'browser',
+        format: 'esm',
+        target: ['chrome58', 'firefox57', 'safari11'],
+        bundle: true,
+        packages: 'external',
+        logLevel: 'silent',
+        metafile: true,
+        write: false,
+      });
+
+      const [output] = Object.values(result.metafile.outputs);
+      const imported = new Set(
+        output.imports.map((entry) => entry.path).filter(isBuiltin),
+      );
+
+      expect(imported).toEqual(ALIASED_NODE_BUILTINS);
+    },
+    BUNDLE_TIMEOUT_MS,
+  );
+
+  it('does not export the Node-only skills and web-page symbols', () => {
+    for (const name of NODE_ONLY_EXPORTS) {
+      expect(
+        web,
+        `${name} leaked into the browser entry point`,
+      ).not.toHaveProperty(name);
+    }
+  });
+
+  it('still exports the platform-neutral symbols', () => {
+    expect(web).toHaveProperty('LlmAgent');
+    expect(web).toHaveProperty('InMemorySessionService');
+  });
+});
+
+describe('Node entry point', () => {
+  it('still exports the Node-only skills and web-page symbols', () => {
+    for (const name of NODE_ONLY_EXPORTS) {
+      expect(
+        adk,
+        `${name} disappeared from the Node entry point`,
+      ).toHaveProperty(name);
+    }
+  });
+});