diff --git a/js/testapps/anthropic/package.json b/js/testapps/anthropic/package.json
index 08e1a0d2fd..b5a21749b0 100644
--- a/js/testapps/anthropic/package.json
+++ b/js/testapps/anthropic/package.json
@@ -13,6 +13,7 @@
     "dev:stable:text-plain": "genkit start -- npx tsx --watch src/stable/text-plain.ts",
     "dev:stable:webp": "genkit start -- npx tsx --watch src/stable/webp.ts",
     "dev:stable:pdf": "genkit start -- npx tsx --watch src/stable/pdf.ts",
+    "dev:stable:tools": "genkit start -- npx tsx --watch src/stable/tools.ts",
     "genkit:dev": "cross-env GENKIT_ENV=dev npm run dev:stable",
     "genkit:start": "cross-env GENKIT_ENV=dev genkit start -- tsx --watch src/stable/basic.ts",
     "dev": "export GENKIT_RUNTIME_ID=$(openssl rand -hex 8) && node lib/stable/basic.js 2>&1"
diff --git a/js/testapps/anthropic/src/stable/tools.ts b/js/testapps/anthropic/src/stable/tools.ts
new file mode 100644
index 0000000000..1e450a302e
--- /dev/null
+++ b/js/testapps/anthropic/src/stable/tools.ts
@@ -0,0 +1,53 @@
+/**
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { anthropic } from '@genkit-ai/anthropic';
+import { genkit, z } from 'genkit';
+
+const ai = genkit({
+  plugins: [
+    // Configure the plugin with environment-driven API key
+    anthropic(),
+  ],
+});
+
+const getWeather = ai.defineTool(
+  {
+    name: 'getWeather',
+    description: 'Gets the current weather in a given location',
+    inputSchema: z.object({
+      location: z
+        .string()
+        .describe('The location to get the current weather for'),
+    }),
+    outputSchema: z.string(),
+  },
+  async (input: any) => {
+    // Here, we would typically make an API call or database query. For this
+    // example, we just return a fixed value.
+    return `The current weather in ${input.location} is 63°F and sunny.`;
+  }
+);
+
+ai.defineFlow('anthropic-stable-tools', async ({ place }) => {
+  const { text } = await ai.generate({
+    model: anthropic.model('claude-sonnet-4-5'),
+    tools: [getWeather],
+    prompt: `What is the weather in ${place}?`,
+  });
+
+  return text;
+});