Error "The caller must be one of the members specified in request body" when creating one-on-one chat

Question

I'm encountering an issue while attempting to create a one-on-one chat in Microsoft Teams using the Microsoft Graph API. Here's the error response I'm receiving:

"code": "BadRequest", "message": "The caller must be one of the members specified in request body."  

I'm using the Microsoft Graph SDK with the following structure for the chat members:

{ 
"@odata.type": "#microsoft.graph.aadUserConversationMember", 
"roles": ["owner"], 
"user@odata.bind": "https://graph.microsoft.com/v1.0/users('{user_principal_name}')" 
}  

The members array in the payload includes both the sender and the receiver of the chat message. So it is not clear to me why it is showing this BadRequest.

I have verified that I have all the necessary API permissions and authorization configured correctly.

Does anyone have insights into what might be causing this error?

Answer 1

Hi @Ruben

If you are creating a one-on-one chat in a delegated context, the logged in user must be one of the members of the chat.

POST https://graph.microsoft.com/v1.0/chats
Content-Type: application/json
{
  "chatType": "oneOnOne",
  "members": [
    {
      "@odata.type": "#microsoft.graph.aadUserConversationMember",
      "roles": ["owner"],
      "user@odata.bind": "https://graph.microsoft.com/v1.0/users('{currently logged in user id}')"
    },
    {
      "@odata.type": "#microsoft.graph.aadUserConversationMember",
      "roles": ["owner"],
      "user@odata.bind": "https://graph.microsoft.com/v1.0/users('xxxxxxxxxxxxxxxxxxxxxxxxxx')"
    }
  ]
}

Hope this helps.

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Answer 2

Hello Ruben,

Thank you for reaching out to Microsoft Support!

The error message "The caller must be one of the members specified in request body" typically indicates that the user making the API call is not included in the members array of the chat creation request. Verify that the user who is making the API call (the caller) is indeed one of the members specified in the request body. Both the sender and the receiver should be included in the members array.

If you do not want to provide signed-in user and want to provide two other users then you should use Application permissions.

Hope this helps.

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