Channels - Microsoft Graph .NET SDK

Overview

The Channels API provides operations to manage channels within Microsoft Teams. Access through graphClient.Teams[teamId].Channels.

Request Builder

public ChannelsRequestBuilder Channels { get; }

Accessed via: graphClient.Teams["team-id"].Channels

Operations

List Channels

Retrieve all channels in a team.

var channels = await graphClient.Teams["team-id"].Channels.GetAsync();

foreach (var channel in channels.Value)
{
    Console.WriteLine($"{channel.DisplayName}");
    Console.WriteLine($"  Description: {channel.Description}");
    Console.WriteLine($"  Type: {channel.MembershipType}");
    Console.WriteLine($"  Web URL: {channel.WebUrl}");
}

Get Channel by ID

var channel = await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .GetAsync();

Console.WriteLine($"Channel: {channel.DisplayName}");

Get Primary Channel

var primaryChannel = await graphClient.Teams["team-id"]
    .PrimaryChannel
    .GetAsync();

Console.WriteLine($"Primary channel: {primaryChannel.DisplayName}");

Create Channel

// Standard channel
var newChannel = new Channel
{
    DisplayName = "Project Updates",
    Description = "Channel for project status updates",
    MembershipType = ChannelMembershipType.Standard
};

var channel = await graphClient.Teams["team-id"]
    .Channels
    .PostAsync(newChannel);

// Private channel
var privateChannel = new Channel
{
    DisplayName = "Leadership",
    Description = "Private channel for leadership team",
    MembershipType = ChannelMembershipType.Private,
    Members = new List<ConversationMember>
    {
        new AadUserConversationMember
        {
            Roles = new List<string> { "owner" },
            AdditionalData = new Dictionary<string, object>
            {
                {
                    "[email protected]",
                    $"https://graph.microsoft.com/v1.0/users/{userId}"
                }
            }
        }
    }
};

var channel = await graphClient.Teams["team-id"]
    .Channels
    .PostAsync(privateChannel);

Update Channel

var updateChannel = new Channel
{
    DisplayName = "Updated Channel Name",
    Description = "Updated description"
};

await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .PatchAsync(updateChannel);

Delete Channel

await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .DeleteAsync();

Messages

List Messages

var messages = await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Messages
    .GetAsync();

foreach (var message in messages.Value)
{
    Console.WriteLine($"{message.From.User.DisplayName}: {message.Body.Content}");
    Console.WriteLine($"Created: {message.CreatedDateTime}");
}

Send Message

var newMessage = new ChatMessage
{
    Body = new ItemBody
    {
        ContentType = BodyType.Html,
        Content = "<p>Hello team! <at id='0'>John</at></p>"
    },
    Mentions = new List<ChatMessageMention>
    {
        new ChatMessageMention
        {
            Id = 0,
            MentionText = "John",
            Mentioned = new ChatMessageMentionedIdentitySet
            {
                User = new TeamworkUserIdentity
                {
                    Id = "user-id",
                    DisplayName = "John Doe"
                }
            }
        }
    }
};

var message = await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Messages
    .PostAsync(newMessage);

Reply to Message

var reply = new ChatMessage
{
    Body = new ItemBody
    {
        ContentType = BodyType.Text,
        Content = "Thanks for the update!"
    }
};

await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Messages["message-id"]
    .Replies
    .PostAsync(reply);

Get Message with Replies

var message = await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Messages["message-id"]
    .GetAsync(config =>
{
    config.QueryParameters.Expand = new[] { "replies" };
});

Update Message

var updateMessage = new ChatMessage
{
    Body = new ItemBody
    {
        ContentType = BodyType.Html,
        Content = "<p>Updated message content</p>"
    }
};

await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Messages["message-id"]
    .PatchAsync(updateMessage);

Delete Message (Soft Delete)

await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Messages["message-id"]
    .SoftDelete
    .PostAsync();

Members (Private Channels)

List Channel Members

var members = await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Members
    .GetAsync();

foreach (var member in members.Value)
{
    if (member is AadUserConversationMember userMember)
    {
        Console.WriteLine($"{userMember.DisplayName} - Roles: {string.Join(", ", userMember.Roles)}");
    }
}

Add Channel Member

var newMember = new AadUserConversationMember
{
    Roles = new List<string>(), // Empty for member, ["owner"] for owner
    AdditionalData = new Dictionary<string, object>
    {
        {
            "[email protected]",
            $"https://graph.microsoft.com/v1.0/users/{userId}"
        }
    }
};

await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Members
    .PostAsync(newMember);

Remove Channel Member

await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Members["membership-id"]
    .DeleteAsync();

Tabs

List Tabs

var tabs = await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Tabs
    .GetAsync();

foreach (var tab in tabs.Value)
{
    Console.WriteLine($"{tab.DisplayName} - {tab.WebUrl}");
}

Add Tab

// Add website tab
var websiteTab = new TeamsTab
{
    DisplayName = "Project Portal",
    AdditionalData = new Dictionary<string, object>
    {
        {
            "[email protected]",
            "https://graph.microsoft.com/v1.0/appCatalogs/teamsApps/com.microsoft.teamspace.tab.web"
        }
    },
    Configuration = new TeamsTabConfiguration
    {
        ContentUrl = "https://contoso.com/project",
        WebsiteUrl = "https://contoso.com/project"
    }
};

// Add OneNote tab
var onenoteTab = new TeamsTab
{
    DisplayName = "Meeting Notes",
    AdditionalData = new Dictionary<string, object>
    {
        {
            "[email protected]",
            "https://graph.microsoft.com/v1.0/appCatalogs/teamsApps/0d820ecd-def2-4297-adad-78056cde7c78"
        }
    },
    Configuration = new TeamsTabConfiguration
    {
        EntityId = "notebook-id",
        ContentUrl = "https://onenote.com/...",
        WebsiteUrl = "https://onenote.com/..."
    }
};

await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Tabs
    .PostAsync(websiteTab);

Update Tab

var updateTab = new TeamsTab
{
    DisplayName = "Updated Tab Name"
};

await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Tabs["tab-id"]
    .PatchAsync(updateTab);

Remove Tab

await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Tabs["tab-id"]
    .DeleteAsync();

Files Folder

Access SharePoint document library for channel files.

// Get files folder
var filesFolder = await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .FilesFolder
    .GetAsync();

Console.WriteLine($"Files URL: {filesFolder.WebUrl}");

// List files
var driveId = filesFolder.ParentReference.DriveId;
var folderId = filesFolder.Id;

var files = await graphClient.Drives[driveId]
    .Items[folderId]
    .Children
    .GetAsync();

foreach (var file in files.Value)
{
    Console.WriteLine($"{file.Name} - {file.Size} bytes");
}

Provision Email Address

var result = await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .ProvisionEmail
    .PostAsync();

Console.WriteLine($"Email: {result.Email}");

Remove Email Address

await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .RemoveEmail
    .PostAsync();

Archive Channel

await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Archive
    .PostAsync();

Unarchive Channel

await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Unarchive
    .PostAsync();

Shared with Teams

List Shared Channels

var sharedChannels = await graphClient.Teams["team-id"]
    .Channels
    .GetAsync(config =>
{
    config.QueryParameters.Filter = "membershipType eq 'shared'";
});

Hosted Content

Upload Image to Message

// First upload hosted content
var hostedContent = new ChatMessageHostedContent
{
    ContentBytes = imageBytes,
    ContentType = "image/png"
};

var uploaded = await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Messages["message-id"]
    .HostedContents
    .PostAsync(hostedContent);

// Then reference in message
var message = new ChatMessage
{
    Body = new ItemBody
    {
        ContentType = BodyType.Html,
        Content = $"<div><img src='../hostedContents/{uploaded.Id}/$value'></div>"
    }
};

Channel Types

Standard Channel

Visible to all team members
Maximum 200 standard channels per team

Private Channel

Only visible to channel members
Maximum 30 private channels per team
Each private channel has its own SharePoint site

Shared Channel

Can be shared with people outside the team
Requires Azure AD B2B

Common Patterns

Send Formatted Message with Mentions

var message = new ChatMessage
{
    Body = new ItemBody
    {
        ContentType = BodyType.Html,
        Content = @"
            <h1>Project Update</h1>
            <p><at id='0'>John</at>, please review the latest changes.</p>
            <ul>
                <li>Feature complete</li>
                <li>Testing in progress</li>
            </ul>
        "
    },
    Mentions = new List<ChatMessageMention>
    {
        new ChatMessageMention
        {
            Id = 0,
            MentionText = "John",
            Mentioned = new ChatMessageMentionedIdentitySet
            {
                User = new TeamworkUserIdentity
                {
                    Id = "user-id",
                    DisplayName = "John Doe"
                }
            }
        }
    }
};

Monitor Channel for New Messages

var lastCheck = DateTime.UtcNow.AddMinutes(-5);

var messages = await graphClient.Teams["team-id"]
    .Channels["channel-id"]
    .Messages
    .GetAsync(config =>
{
    config.QueryParameters.Filter = $"createdDateTime gt {lastCheck:yyyy-MM-ddTHH:mm:ssZ}";
});

Error Handling

using Microsoft.Graph.Models.ODataErrors;

try
{
    var channel = await graphClient.Teams["team-id"]
        .Channels["channel-id"]
        .GetAsync();
}
catch (ODataError error)
{
    if (error.Error.Code == "NotFound")
    {
        Console.WriteLine("Channel not found");
    }
    else if (error.Error.Code == "Forbidden")
    {
        Console.WriteLine("Access denied to channel");
    }
    else
    {
        Console.WriteLine($"Error: {error.Error.Message}");
    }
}

Channel Model

Channel resource properties

Teams API

Team operations

Chats API

Chat operations

Chat Messages

Message resource

Client

Users & Groups

Mail & Calendar

Files & Drives

Teams & Communication

Identity & Access

​Overview

​Request Builder

​Operations

​List Channels

​Get Channel by ID

​Get Primary Channel

​Create Channel

​Update Channel

​Delete Channel

​Messages

​List Messages

​Send Message

​Reply to Message

​Get Message with Replies

​Update Message

​Delete Message (Soft Delete)

​Members (Private Channels)

​List Channel Members

​Add Channel Member

​Remove Channel Member

​Tabs

​List Tabs

​Add Tab

​Update Tab

​Remove Tab

​Files Folder

​Provision Email Address

​Remove Email Address

​Archive Channel

​Unarchive Channel

​Shared with Teams

​List Shared Channels

​Hosted Content

​Upload Image to Message

​Channel Types

​Standard Channel

​Private Channel

​Shared Channel

​Common Patterns

​Send Formatted Message with Mentions

​Monitor Channel for New Messages

​Error Handling

​See Also