Bot utterances are not forwarded to latest channel

My application uses the websockets for communication with RASA. A conversation_id is successfully set and the interactions return the expected behavior through the chatbot. My issue right now occurs when I test a call to the HTTP API to execute and action per thedocumentation: HTTP API the utterance is not forwarded to the channel.

URL: http://localhost:5005/conversations/MjU4OTQ5/execute

Payload: {

    "name": "utter_hello",
    "policy": "string",
    "confidence": 0.987232,
    "output_channel" : "latest"



                "event": "action",
                "timestamp": 1578604652.2660300732,
                "name": "utter_hello",
                "policy": "string",
                "confidence": 0.987232
                "event": "bot",
                "timestamp": 1578604652.2660424709,
                "text": "Hi, this is your bot 🤖",
                "data": {
                    "elements": null,
                    "quick_replies": null,
                    "buttons": null,
                    "attachment": null,
                    "image": null,
                    "custom": null
                "metadata": {}
        "latest_input_channel": "socketio",
        "active_form": {},
        "latest_action_name": "utter_hello"
    "messages": [
            "recipient_id": "MjU4OTQ5",
            "text": "Hi, this is your bot 🤖"

CoreServer log when the HTTP API is called:

CoreServer log when we use the chatbot:

Am I missing something? Regards

As mentioned in the HTTP API websockets do not support the output channel parameter in the /execute endpoint.

Currently supported channels are listed in the permitted values for the parameter.

Values are:

Enum: “latest” “slack” “callback” “facebook” “rocketchat” “telegram” “twilio” “webexteams”

Thank you for the information @Tanja.

So where do you specify the output channel parameter if its not in the payload to the /execute endpoint?

headers = {'content-type': 'application/json', 'Accept-Charset': 'UTF-8','output_channel':'latest'}
url =     http://localhost:5005/conversations/0d1923e5-ad83-4802-8228-138569aa6f41/execute'
r =, data=json.dumps(data),headers=headers)

Also could rasa_core==11.1 handle defining the output_channel as query parameter argument when sending a http request?

@ahson You can still define the output channel as defined in the HTTP API. However, the values that Rasa supports for the output channel are limited to “latest”, “slack”, “callback”, “facebook”, “rocketchat”, “telegram”, “twilio”, “webexteams”. The output channel is defined as query parameter.