Using an mqtt client with event mesh (python)

schmeli — Thu, 20 Nov 2025 14:50:28 GMT

Hi,
I implemented a python script which connects to event mesh and subscribes to a queue.
The oauth token is retrieved successfully and the connection is established.
However every time the client tries to subscribe to a queue, the connection is closed.
This is also the case when the client tries sending a keepalive message.
This is my code:

import paho.mqtt.client as mqtt import requests import time # ---------- Configuration ---------- BROKER_URL = "xxxx" # Replace with your MQTT broker URL BROKER_PORT = 443 # Typically 8883 for TLS TOPIC = "testOrgName/testEventMesh/1/test_queue" # OAuth Configuration OAUTH_TOKEN_URL = "xxx" # OAuth token endpoint CLIENT_ID = "xxx" CLIENT_SECRET = "xxx" SCOPE = "mqtt.subscribe" # ----------------------------------- def get_oauth_token(): """Fetch a new OAuth access token""" payload = { 'grant_type': 'client_credentials', } response = requests.post(OAUTH_TOKEN_URL, auth=(CLIENT_ID, CLIENT_SECRET), params=payload) response.raise_for_status() token = response.json().get("access_token") return token # MQTT Callbacks def on_connect(client, userdata, flags, rc): if rc == 0: print("Connected successfully!") #client.subscribe(TOPIC) #client.publish(TOPIC, "Hello, MQTT!", qos=1) print(f"Subscribed to topic: {TOPIC}") else: print(f"Connection failed with code {rc}") def on_message(client, userdata, msg): print(f"Received message: {msg.payload.decode()} on topic {msg.topic}") def on_disconnect(client, userdata, rc): print(f"lost connection with reason {rc}") def on_log(client, userdata, level, buf): print(f"{level}: {buf}") def main(): # Get OAuth token token = get_oauth_token() print("Obtained OAuth token") # Create MQTT client client = mqtt.Client(transport="websockets", client_id="xyz") # Assign callbacks client.on_connect = on_connect client.on_message = on_message client.on_disconnect = on_disconnect client.on_log = on_log # maybe not even necessary client.tls_set(ca_certs="./_.cf.eu10.hana.ondemand.com") client.ws_set_options(path="/protocols/mqtt311ws", headers={"Authorization": f"Bearer {token}"}) # Connect to broker client.connect(BROKER_URL, BROKER_PORT) # Start network loop client.loop_start() try: while True: # Keep running or refresh token periodically if needed time.sleep(10) except KeyboardInterrupt: print("Disconnecting...") client.loop_stop() client.disconnect() if __name__ == "__main__": main()

I have tried setting a different client id and I have verified that the topic coincides with the queue name and the queue naming rules in the service descriptor. I have also verified, that enough connections are open (there is no other connection). I also have verified, that the client is indeed connected to event mesh using the resource usage where it is, for some reason, marked as a producer.

My suspicion now is, that for some reason i have to enable the mqtt functionality or at least give some permissions for mqtt or something.

what would also be helpful would be something where i can see the logs of the mqtt broker in event mesh or at least any kind of logs.

-- EDIT --

I have found out, that for some reason the standalone event mesh and the integration suite event mesh behave differently. Using exactly the same script, subscribing to a topic does not disconnect the client and messages can be received, as long as messages are solely published to a topic in event mesh integration suite. I have no knowledge about subscribing to a queue.

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Using an mqtt client with event mesh (python)