microsoft/semantic-kernel · error · NotSupportedException

{nameof(CopilotStudioAgent)} is not for use with {nameof(Age

Error message

{nameof(CopilotStudioAgent)} is not for use with {nameof(AgentChat)}.

What it means

Thrown by CopilotStudioAgent.GetChannelKeys() to signal that CopilotStudioAgent does not participate in the multi-agent AgentChat channel coordination system. The Copilot Studio integration is designed for direct single-agent invocation only; it overrides the channel-related abstract members to throw NotSupportedException to make the limitation explicit at the point AgentChat would try to use them.

Source

Thrown at dotnet/src/Agents/Copilot/CopilotStudioAgent.cs:127

            {
                await options.OnIntermediateMessage(result).ConfigureAwait(false);
            }

            StreamingChatMessageContent streamedResult = new(result.Role, content: null)
            {
                Items = [.. ContentProcessor.ConvertToStreaming(result.Items, this.Logger)],
                InnerContent = result.InnerContent,
                Metadata = result.Metadata,
            };

            yield return new(streamedResult, agentThread);
        }
    }

    /// <inheritdoc/>
    protected override IEnumerable<string> GetChannelKeys()
    {
        throw new NotSupportedException($"{nameof(CopilotStudioAgent)} is not for use with {nameof(AgentChat)}.");
    }

    /// <inheritdoc/>
    protected override Task<AgentChannel> CreateChannelAsync(CancellationToken cancellationToken)
    {
        throw new NotSupportedException($"{nameof(CopilotStudioAgent)} is not for use with {nameof(AgentChat)}.");
    }

    /// <inheritdoc/>
    protected override Task<AgentChannel> RestoreChannelAsync(string channelState, CancellationToken cancellationToken)
    {
        throw new NotSupportedException($"{nameof(CopilotStudioAgent)} is not for use with {nameof(AgentChat)}.");
    }

    private IAsyncEnumerable<ChatMessageContent> InvokeInternalAsync(ICollection<ChatMessageContent> messages, CopilotStudioAgentThread thread, CancellationToken cancellationToken)
    {
        string question = string.Join(Environment.NewLine, messages.Select(m => m.Content));

View on GitHub (pinned to c028a0c7dc)

Solutions

Do not use CopilotStudioAgent with AgentChat. Invoke it directly via InvokeAsync/InvokeStreamingAsync with a CopilotStudioAgentThread.
If multi-agent orchestration is needed, host the Copilot Studio agent behind a custom adapter that is not registered with AgentChat.
Use a different agent type that supports the AgentChat channel model for multi-agent scenarios.

Example fix

// before — not supported
var chat = new AgentChat { };
chat.AddAgent(copilotAgent); // triggers GetChannelKeys -> NotSupportedException

// after — invoke directly
var thread = new CopilotStudioAgentThread(client);
await foreach (var r in copilotAgent.InvokeAsync(messages, thread)) { ... }

Defensive patterns

Strategy: validation

Validate before calling

// Do not register CopilotStudioAgent with AgentChat
if (agent is CopilotStudioAgent)
    throw new InvalidOperationException("CopilotStudioAgent cannot be used with AgentChat. Invoke directly.");

Type guard

static bool SupportsAgentChat(Microsoft.SemanticKernel.Agents.Agent a) =>
    a is not CopilotStudioAgent;

Try / catch

try { chat.AddAgent(agent); }
catch (NotSupportedException ex) when (ex.Message.Contains("AgentChat"))
{
    logger.LogError("CopilotStudioAgent does not support AgentChat. Use direct InvokeAsync instead.");
    throw;
}

Prevention

Keep CopilotStudioAgent out of any AgentChat configuration.
Invoke CopilotStudioAgent directly with a CopilotStudioAgentThread.
Document in your codebase that Copilot Studio agents are single-agent, direct-invoke only.

When it happens

Trigger: Adding a CopilotStudioAgent to an AgentChat (multi-agent chat) instance, which internally calls GetChannelKeys() to coordinate channels across agents. Because Copilot Studio uses its own conversation/session model, it cannot be wired into the shared channel abstraction.

Common situations: Migrating from a single-agent OpenAI/Bedrock setup to a multi-agent AgentChat and including a Copilot Studio agent; following a multi-agent sample and substituting CopilotStudioAgent.

Related errors

AI-assisted analysis of microsoft/semantic-kernel@c028a0c7dc (2026-08-13). Data as JSON: /api/errors/e15f68262b456cc2. Report an issue: GitHub.