[Bug]: invoke.composeExtension/fetchTask.value.commandContext is missing for iOS Teams App

[aviadpriel]

Bug Description

Failed send composeExtension/fetchTask event from the iOS Teams app

example Event
{
"name": "composeExtension/fetchTask",
"type": "invoke",
"timestamp": "2025-12-17T13:46:40.451Z",
"localTimestamp": "2025-12-17T15:46:40.451+02:00",
"id": "f:62dcf698-cda3-f257-78b9-88872540a0b3",
"channelId": "msteams",
"serviceUrl": "https://smba.trafficmanager.net/il/4af974d3-98ed-4c0e-959d-a8a6eabb1fe5/",
"from": {
"id": "29:1S_F5LY_8qCPjyorfT7Gj5vmFYNoj1NhWnjwSVcOU4ayU7n1lOxKDcXAqycCzJN6YsMrgFZJAxvEuoZQ8o1S8pw",
"name": "Hodaya Baruch",
"aadObjectId": "93a2643b-9007-40d4-a29e-5c4fdcd92f0c"
},
"conversation": {
"isGroup": true,
"conversationType": "channel",
"tenantId": "4af974d3-98ed-4c0e-959d-a8a6eabb1fe5",
"id": "19:779d85a2434c4633b29979ff514dafba@thread.tacv2",
"name": "Ask_Legal"
},
"recipient": {
"id": "28:ad596c08-aa7c-4c30-88f1-e829f26c084e",
"name": "chamelio-local-bot"
},
"entities": [
{
"locale": "he-IL",
"country": "IL",
"platform": "iOS",
"timezone": "Asia/Jerusalem",
"type": "clientInfo"
}
],
"channelData": {
"channel": {
"id": "19:779d85a2434c4633b29979ff514dafba@thread.tacv2"
},
"team": {
"id": "19:iIgkaHS_Z2FDGrcebiPcRW08jLbWfcpNC1wXhKemwaY1@thread.tacv2"
},
"tenant": {
"id": "4af974d3-98ed-4c0e-959d-a8a6eabb1fe5"
},
"source": {
"name": "compose"
},
"legacy": {
"replyToId": "1:1C5t23F4GBgk06KBiIOVQKvoPA5Fh5vvzUlVt6ETIJFY"
}
},
"replyToId": "0",
"value": {
"context": {
"theme": "default"
},
"commandId": "workflows_intake_get_forms",
"state": ""
},
"locale": "he-IL",
"localTimezone": "Asia/Jerusalem"
}

Steps to Reproduce

Send composeExtension/fetchTask event from the iOS Teams app

Expected Behavior

Work like the rest of the Platforms or hide the apps from IOS

Actual Behavior

500 on the Teams app

pydantic_core._pydantic_core.ValidationError: 1 validation error for tagged-union[HandoffActivity,TraceActivity,TypingActivity,CommandSendActivity,CommandResultActivity,ConversationUpdateActivity,EndOfConversationActivity,MessageActivity,MessageDeleteActivity,MessageReactionActivity,MessageUpdateActivity,tagged-union[ReadReceiptEventActivity,MeetingStartEventActivity,MeetingEndEventActivity,MeetingParticipantJoinEventActivity,MeetingParticipantLeaveEventActivity],tagged-union[FileConsentInvokeActivity,ExecuteActionInvokeActivity,MessageExtensionAnonQueryLinkInvokeActivity,MessageExtensionCardButtonClickedInvokeActivity,MessageExtensionFetchTaskInvokeActivity,MessageExtensionQueryInvokeActivity,MessageExtensionQueryLinkInvokeActivity,MessageExtensionQuerySettingUrlInvokeActivity,MessageExtensionSelectItemInvokeActivity,MessageExtensionSettingInvokeActivity,MessageExtensionSubmitActionInvokeActivity,ConfigFetchInvokeActivity,ConfigSubmitInvokeActivity,TabFetchInvokeActivity,TabSubmitInvokeActivity,TaskFetchInvokeActivity,TaskSubmitInvokeActivity,MessageSubmitActionInvokeActivity,HandoffActionInvokeActivity,SignInTokenExchangeInvokeActivity,SignInVerifyStateInvokeActivity,SignInFailureInvokeActivity,AdaptiveCardInvokeActivity],tagged-union[InstalledActivity,UninstalledActivity]]
invoke.composeExtension/fetchTask.value.commandContext
Field required [type=missing, input_value={'context': {'theme': 'de...get_forms', 'state': ''}, input_type=dict]
For further information visit https://errors.pydantic.dev/2.12/v/missing

invoke.composeExtension/fetchTask.value.commandContext is missing

example Event from my bot
{
"name": "composeExtension/fetchTask",
"type": "invoke",
"timestamp": "2025-12-17T13:46:40.451Z",
"localTimestamp": "2025-12-17T15:46:40.451+02:00",
"id": "f:62dcf698-cda3-f257-78b9-88872540a0b3",
"channelId": "msteams",
"serviceUrl": "https://smba.trafficmanager.net/il/4af974d3-98ed-4c0e-959d-a8a6eabb1fe5/",
"from": {
"id": "29:1S_F5LY_8qCPjyorfT7Gj5vmFYNoj1NhWnjwSVcOU4ayU7n1lOxKDcXAqycCzJN6YsMrgFZJAxvEuoZQ8o1S8pw",
"name": "Hodaya Baruch",
"aadObjectId": "93a2643b-9007-40d4-a29e-5c4fdcd92f0c"
},
"conversation": {
"isGroup": true,
"conversationType": "channel",
"tenantId": "4af974d3-98ed-4c0e-959d-a8a6eabb1fe5",
"id": "19:779d85a2434c4633b29979ff514dafba@thread.tacv2",
"name": "Ask_Legal"
},
"recipient": {
"id": "28:ad596c08-aa7c-4c30-88f1-e829f26c084e",
"name": "chamelio-local-bot"
},
"entities": [
{
"locale": "he-IL",
"country": "IL",
"platform": "iOS",
"timezone": "Asia/Jerusalem",
"type": "clientInfo"
}
],
"channelData": {
"channel": {
"id": "19:779d85a2434c4633b29979ff514dafba@thread.tacv2"
},
"team": {
"id": "19:iIgkaHS_Z2FDGrcebiPcRW08jLbWfcpNC1wXhKemwaY1@thread.tacv2"
},
"tenant": {
"id": "4af974d3-98ed-4c0e-959d-a8a6eabb1fe5"
},
"source": {
"name": "compose"
},
"legacy": {
"replyToId": "1:1C5t23F4GBgk06KBiIOVQKvoPA5Fh5vvzUlVt6ETIJFY"
}
},
"replyToId": "0",
"value": {
"context": {
"theme": "default"
},
"commandId": "workflows_intake_get_forms",
"state": ""
},
"locale": "he-IL",
"localTimezone": "Asia/Jerusalem"
}

SDK Version

2.0.0a8

Python Version

3.13

Additional Context

No response

[lilyydu]

Hi @aviadpriel,

Thanks for filing this ticket. Investigating now with the iOS team on the payload difference

[lilyydu]

@aviadpriel -

1. To clarify, do you mean you are receiving the "composeExtension/fetchTask" event, after clicking onto a messaging extension?
2. Also, is your bot a specialized bot (custom engine agent, declarative, etc)?
3. Did you test this on Web/Client/Android? Did you only get this error on iOS?
4. Can you attach your code snippet for message extensions?