Validation fails when receiving a message from Direct Line - missing conversationUpdate.channelData #239
Description
teams.py/packages/apps/src/microsoft_teams/apps/http_plugin.py
Lines 312 to 316 in 4577e0b
Hi everyone,
This is my situation: I have an Azure Function leveraging Direct Line API 3.0 that I use to call a chatbot which has Teams SDK for Python, running on an Azure App Service.
On the Function side, I authenticate and return the conversation id:
url = "https://directline.botframework.com/v3/directline/conversations"
headers = {
"Authorization": f"Bearer {direct_line_secret}",
"Content-Type": "application/json",
}
[...]
conversation_data = response.json()
conversation_id = conversation_data.get("conversationId")
return conversation_id
I get the initial activities then I send an activity to a Direct Line conversation:
# Get activities from a Direct Line conversation
try:
url = f"https://directline.botframework.com/v3/directline/conversations/{conversation_id}/activities"
if watermark:
url += f"?watermark={watermark}"
headers = {
"Authorization": f"Bearer {direct_line_secret}",
}
response = requests.get(url, headers=headers, timeout=30)
[...]
# send acvitivity
try:
url = f"https://directline.botframework.com/v3/directline/conversations/{conversation_id}/activities"
headers = {
"Authorization": f"Bearer {direct_line_secret}",
"Content-Type": "application/json",
}
[...]
response = requests.post(
url, json=activity_payload, headers=headers, timeout=30
)
I get the activities again.
I send two payloads to test the bots (on separate POSTs):
{
"channelId": "directline",
"conversation": {
"id": "conv123"
},
"from": {
"id": "user123",
"name": "Test User"
},
"text": "Give me all the Orders",
"type": "message"
},
{
"channelId": "directline",
"conversation": {
"id": "conv123"
},
"from": {
"id": "user123",
"name": "Test User"
},
"text": "Give me all the Orders that are pending",
"type": "message"
}
When I send the first one I get this error on the App Service side which is using Teams SDK:
{
"type": "missing",
"loc": [
"conversationUpdate",
"channelData"
],
"msg": "Field required",
"input": {
"type": "conversationUpdate",
"id": "Bh0ETfRaC25",
"timestamp": "2025-12-22T11:29:37.3485747Z",
"serviceUrl": "https://directline.botframework.com/",
"channelId": "directline",
"from": {
"id": "dl_aba7a98ada0ee99e7d54af5df8e00440",
"name": "Bot Tester"
},
[...]
]
},
"url": "https://errors.pydantic.dev/2.12/v/missing"
}
[31m[1m[ERROR] @teams/app.BotBuilderPlugin[0m[22m conversationUpdate.channelData
[31m[1m[ERROR] @teams/app.BotBuilderPlugin[0m[22m Field required [type=missing, input_value={'type': 'conversationUpd... 'name': 'Bot Tester'}]}, input_type=dict]
It says that conversationUpdate.channelData is missing, and I get a 502 error on the function side.
The second message, funny enough, is sent and received with no errors.
From what I can see, when you start a conversation via Direct Line, the service automatically sends conversationUpdate activities to your bot before you even send your first message. You can't stop this.
Documentation
POST https://directline.botframework.com/v3/directline/tokens/generate
[...]
Direct Line can perform additional security validation of the user ID and name, inhibiting tampering of these values by malicious clients. Including these values also improves Direct Line's ability to send the conversation update activity, allowing it to generate the conversation update immediately upon the user joining the conversation. When this information isn't provided, the user must send content before Direct Line can send the conversation update
When generating a token, Direct Line generates a conversationUpdate object that I can't prevent and has no channelData. This trips the Team's framework validation because it's mandatory on the other side.
This is a mismatch in behaviour we have to patch ourselves.
For Bot's framework channelData is optional: https://learn.microsoft.com/en-us/javascript/api/botframework-schema/activity?view=botbuilder-ts-latest
channelData?: any # Optional
tl;dr: Direct Line sends a conversationUpdate with no channelData, Teams SDK wants this, I can't change the behaviour.
This wasn't happening when we used the Bot Builder framework this wasn't happening.
Do you have any ideas on how I could solve this?
Thanks in advance for the help.