diff --git a/README.md b/README.md
index acb4064..c579a24 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ All services can be launched together with `docker-compose`.
 ## Usage
 
 1. Configure the URL of your LLM agent in `docker-compose.yml` (`LLM_AGENT_URL`).
-2. Optionally edit `whatsapp-router/src/chatHandlers.ts` to map specific chat IDs to different handler URLs.
+2. Optionally edit `whatsapp-router/src/chatHandlers.ts` to map specific chat IDs to different handler URLs or local handlers. By default the chat ID `50498554225@c.us` is mapped to a built‑in *HelloWorld* agent that replies "hello world" for testing.
 3. Run:
 
 ```bash
diff --git a/whatsapp-router/src/chatHandlers.ts b/whatsapp-router/src/chatHandlers.ts
index efc7be8..623aa07 100644
--- a/whatsapp-router/src/chatHandlers.ts
+++ b/whatsapp-router/src/chatHandlers.ts
@@ -1,9 +1,16 @@
-export const chatHandlers: Record<string, string> = {
-  // Example mapping:
+import { helloWorldAgent } from './helloAgent';
+import { WhatsAppMessage } from './types';
+
+export type Handler = string | ((msg: WhatsAppMessage | string) => Promise<string>);
+
+export const chatHandlers: Record<string, Handler> = {
+  '50498554225@c.us': helloWorldAgent,
+  // Add other mappings like:
   // '50496210031@c.us': 'http://llm-agent:8000'
 };
 
-export function getHandler(chatId: string | undefined, defaultUrl?: string): string | undefined {
+export function getHandler(chatId: string | undefined, defaultUrl?: string): Handler | undefined {
+
   if (!chatId) return defaultUrl;
   return chatHandlers[chatId] || defaultUrl;
 }
diff --git a/whatsapp-router/src/helloAgent.ts b/whatsapp-router/src/helloAgent.ts
new file mode 100644
index 0000000..5d0f2a0
--- /dev/null
+++ b/whatsapp-router/src/helloAgent.ts
@@ -0,0 +1,3 @@
+export async function helloWorldAgent(): Promise<string> {
+  return 'hello world';
+}
diff --git a/whatsapp-router/src/index.ts b/whatsapp-router/src/index.ts
index 3e15ebc..8d6b2b8 100644
--- a/whatsapp-router/src/index.ts
+++ b/whatsapp-router/src/index.ts
@@ -1,7 +1,8 @@
 import express from 'express';
 import axios from 'axios';
 import { WhatsAppMessage } from './types';
-import { getHandler } from './chatHandlers';
+import { getHandler, Handler } from './chatHandlers';
+
 
 const app = express();
 
@@ -111,17 +112,27 @@ async function registerWebhook() {
 app.use(express.json());
 
 app.post('/webhook', async (req: express.Request, res: express.Response) => {
-  const { message, text, from } = req.body as { message?: WhatsAppMessage; text?: string; from?: string };
+  const { message, text, from } = req.body as {
+    message?: WhatsAppMessage;
+    text?: string;
+    from?: string;
+  };
+
   const incoming = message || text;
   try {
     if (!incoming) return res.sendStatus(200);
     if (!openWaUrl) throw new Error('Service URLs not configured');
     const chatId = (message && message.chatId) || from;
-    const handlerUrl = getHandler(chatId, agentUrl);
-    if (!handlerUrl) throw new Error('No handler configured');
-    const agentRes = await axios.post(handlerUrl, { message: incoming });
-    const reply = agentRes.data.reply || agentRes.data;
-    await axios.post(`${openWaUrl}/send-text`, { to: from, message: reply });
+    const handler = getHandler(chatId, agentUrl);
+    if (!handler) throw new Error('No handler configured');
+    let reply: string;
+    if (typeof handler === 'string') {
+      const agentRes = await axios.post(handler, { message: incoming });
+      reply = agentRes.data.reply || agentRes.data;
+    } else {
+      reply = await handler(incoming);
+    }
+    await axios.post(`${openWaUrl}/sendText`, { args: { to: from, content: reply } });
   } catch (err: any) {
     console.error('Error processing message', err.message);
   }