diff --git a/src/cvtt/mkt_data.py b/src/cvtt/mkt_data.py
index 9d2c653..0c8aff0 100644
--- a/src/cvtt/mkt_data.py
+++ b/src/cvtt/mkt_data.py
@@ -1,7 +1,9 @@
 #!/usr/bin/env python3
 
 import argparse
+from ast import Sub
 import asyncio
+from functools import partial
 import json
 import logging
 import uuid
@@ -12,9 +14,11 @@ from numpy.strings import str_len
 import websockets
 from websockets.asyncio.client import ClientConnection
 
+MessageTypeT = str
 SubscriptionIdT = str
+MessageT = Dict
 UrlT = str
-CallbackT = Callable[[Dict], Coroutine[None, str, None]]
+CallbackT = Callable[[MessageTypeT, SubscriptionIdT, MessageT], Coroutine[None, str, None]]
 
 @dataclass
 class CvttPricesSubscription:
@@ -66,11 +70,13 @@ class CvttPricerWebSockClient:
     ) -> str:  # returns subscription id
 
         if not self.is_connected_:
-            self.logger_.info(f"Connecting to {self.ws_url_}")
-            self.websocket_ = await websockets.connect(self.ws_url_)
-            self.is_connected_ = True
-        else:
-            raise Exception(f"Unable to connect to {self.ws_url_}")
+            try:
+                self.logger_.info(f"Connecting to {self.ws_url_}")
+                self.websocket_ = await websockets.connect(self.ws_url_)
+                self.is_connected_ = True
+            except Exception as e:
+                self.logger_.error(f"Unable to connect to {self.ws_url_}: {str(e)}")
+                raise e
 
         subscr_msg = {
             "type": "subscr",
@@ -83,6 +89,7 @@ class CvttPricerWebSockClient:
         if subscription.is_historical_:
             subscr_msg["history_depth_sec"] = subscription.history_depth_sec_
 
+        assert self.websocket_ is not None
         await self.websocket_.send(json.dumps(subscr_msg))
 
         response = await self.websocket_.recv()
@@ -109,7 +116,7 @@ class CvttPricerWebSockClient:
             return False
         return False
 
-    async def connect_and_subscribe(self) -> None:
+    async def run(self) -> None:
         assert self.websocket_
         try:
             while self.is_connected_:
@@ -131,51 +138,50 @@ class CvttPricerWebSockClient:
             await asyncio.sleep(5)  # Wait before reconnecting
 
     async def process_message(self, message: Dict) -> None:
-        if message.get("type") in ["md_aggregate", "historical_md_aggregate"]:
-            subscription_id = message.get("id")
+        message_type = message.get("type")
+        if message_type in ["md_aggregate", "historical_md_aggregate"]:
+            subscription_id = message.get("subscr_id")
             if subscription_id not in self.subscriptions_:
                 self.logger_.warning(f"Unknown subscription id: {subscription_id}")
                 return
 
             subscription = self.subscriptions_[subscription_id]
-            await subscription.callback_(message)
+            await subscription.callback_(message_type, subscription_id, message)
         else:
             self.logger_.warning(f"Unknown message type: {message.get('type')}")
 
 
 async def main() -> None:
-    pass
-    # parser = argparse.ArgumentParser(description="WebSocket API Testing Tool")
-    # parser.add_argument("--url", required=True, help="WebSocket API URL")
-    # parser.add_argument(
-    #     "--exchange_config_name", required=True, help="Exchange config name"
-    # )
-    # parser.add_argument(
-    #     "--instrument_ids", required=True, help="Comma separated Instrument IDs"
-    # )
-    # parser.add_argument(
-    #     "--interval_sec", type=int, required=True, help="Interval in seconds"
-    # )
-    # parser.add_argument(
-    #     "--history_depth_sec",
-    #     default=0,
-    #     type=int,
-    #     required=False,
-    #     help="History depth in seconds",
-    # )
+    async def on_message(message_type: MessageTypeT, subscr_id: SubscriptionIdT, message: Dict, instrument_id: str) -> None:
+        print(f"{message_type=} {subscr_id=} {instrument_id}")
+        if message_type == "md_aggregate":
+            aggr = message.get("md_aggregate", [])
+            print(f"[{aggr['tstmp'][:19]}] *** RLTM ***  {message}")
+        elif message_type == "historical_md_aggregate":
+            for aggr in message.get("historical_data", []):
+                print(f"[{aggr['tstmp'][:19]}] *** HIST *** {aggr}")
+        else:
+            print(f"Unknown message type: {message_type}")
+        
+    pricer_client = CvttPricerWebSockClient(
+        "ws://localhost:12346/ws"
+    )
+    await pricer_client.subscribe(CvttPricesSubscription(
+        exchange_config_name="COINBASE_AT",
+        instrument_id="PAIR-BTC-USD",
+        interval_sec=60,
+        history_depth_sec=60*60*24,
+        callback=partial(on_message, instrument_id="PAIR-BTC-USD")
+    ))
+    await pricer_client.subscribe(CvttPricesSubscription(
+        exchange_config_name="COINBASE_AT",
+        instrument_id="PAIR-ETH-USD",
+        interval_sec=60,
+        history_depth_sec=60*60*24,
+        callback=partial(on_message, instrument_id="PAIR-ETH-USD")
+    ))
 
-    # args = parser.parse_args()
-
-    # config = PricerClientConfig(
-    #     url_=args.url,
-    #     exchange_config_name_=args.exchange_config_name,
-    #     instrument_ids_=args.instrument_ids.split(","),
-    #     interval_sec_=args.interval_sec,
-    #     history_depth_sec_=args.history_depth_sec,
-    # )
-
-    # client = CvttPricerWebSockClient(config)
-    # await client.connect_and_subscribe()
+    await pricer_client.run() 
 
 
 if __name__ == "__main__":