Using Graph API to Send Messages in a "One-to-One" Teams Chat from an ASP .Net Core Application

Question

Hello Microsoft Team,

I have the following goal: We want to send a message in a "One-to-One" Teams chat from an ASP .Net Core application. For this, we intended to use the Graph API and have created the following example based on the documentation:

Code Example:

using Azure.Identity;
using Microsoft.Graph.Models;
using Microsoft.Identity.Client;

namespace TeamsExampel
{
    public class TestTeamsMessage
    {
        private string TENANT_ID = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
        private string APP_CLIENT_ID = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
        private string APP_CLIENT_SECRET = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
        private string SERVICEACCOUNT = "******@anaxco.de";

        public async Task SendTeamsMessage()
        {
            await SendMessageAsync("******@anaxco.de", "This is a test message");
        }

        private async Task<object> SendMessageAsync(string receiverEmail, string message)
        {
            var scopesChat = new List<string> { "https://graph.microsoft.com/.default" };
            var options = new ClientCertificateCredentialOptions
            {
                AuthorityHost = AzureAuthorityHosts.AzurePublicCloud
            };

            try
            {
                var clientSecretCredential = new ClientSecretCredential(TENANT_ID, APP_CLIENT_ID, APP_CLIENT_SECRET, options);
                var graphClient = new Microsoft.Graph.GraphServiceClient(clientSecretCredential, scopesChat);

                var userReceiver = await graphClient.Users[receiverEmail].GetAsync();
                var userService = await graphClient.Users[SERVICEACCOUNT].GetAsync();

                if (userReceiver == null)
                {
                    return $"User {receiverEmail} not found.";
                }

                var newChat = new Chat
                {
                    ChatType = ChatType.OneOnOne,
                    TenantId = TENANT_ID,
                    Members = new List<ConversationMember>
             {
                 new AadUserConversationMember
                 {
                     TenantId= TENANT_ID,
                     UserId =userService.Id,
                     Roles = new List<string> { "owner" },
                     AdditionalData = new Dictionary<string, object>
                     {
                         {
                             "******@odata.bind" , $"https://graph.microsoft.com/v1.0/users('{userService.Id}')"
                         },
                     },
                 },
                 new AadUserConversationMember
                 {
                     TenantId= TENANT_ID,
                     UserId= userReceiver.Id,
                     Roles = new List<string> { "owner" },
                     AdditionalData = new Dictionary<string, object>
                     {
                         {
                             "******@odata.bind" , $"https://graph.microsoft.com/v1.0/users('{userReceiver.Id}')"
                         },
                     },
                 }
             },
                };

                var createdChat = await graphClient.Chats.PostAsync(newChat);

                ChatMessage msg = new ChatMessage()
                {
                    CreatedDateTime = DateTime.Now,
                    ChatId = createdChat.Id,
                    From = new ChatMessageFromIdentitySet
                    {
                        User = new Identity
                        {
                            Id = userService.Id,
                            DisplayName = userService.DisplayName,
                        }
                    },
                    MessageType = ChatMessageType.Message,
                    Body = new ItemBody
                    {
                        ContentType = BodyType.Html,
                        Content = message
                    }
                };


                var chatresult = await graphClient.Chats[createdChat.Id].Messages.PostAsync(msg);

                return chatresult;
            }
            catch (Exception ex)
            {
                return ex;
            }
        }
    }
}

Permissions:

We have configured the ASP .Net Core application with the appropriate Application permissions according to the documentation.

Error Message:

We are receiving the following error message when we run the code:
HTTP Status Code 403, InsufficientPrivileges

We’ve been unable to create a working example based on the documentation. We would greatly appreciate your assistance in resolving this issue.

Thank you in advance!

Answer 1

Hi @Carsten Cors

Application permissions are typically used for data migration (importing messages from third-party platforms) rather than sending messages.

To send messages, you should use delegated permissions instead.

Hope this helps.

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