microsoft/semantic-kernel · error · AgentChatException

Agent is not of the expected type {type(AzureAIAgent)}.

Error message

Agent is not of the expected type {type(AzureAIAgent)}.

What it means

Raised by AzureAIChannel.invoke when the agent passed to the channel is not an AzureAIAgent. Each channel type is specific to one agent implementation; the AzureAI channel drives Azure AI Agents API threads and cannot run a different agent type. Surfaced as AgentChatException.

Source

Thrown at python/semantic_kernel/agents/azure_ai/azure_ai_channel.py:62

        """
        for message in history:
            await AgentThreadActions.create_message(self.client, self.thread_id, message)

    @override
    async def invoke(self, agent: "Agent", **kwargs) -> AsyncIterable[tuple[bool, "ChatMessageContent"]]:
        """Invoke the agent.

        Args:
            agent: The agent to invoke.
            kwargs: The keyword arguments.

        Yields:
            tuple[bool, ChatMessageContent]: The conversation messages.
        """
        from semantic_kernel.agents.azure_ai.azure_ai_agent import AzureAIAgent

        if not isinstance(agent, AzureAIAgent):
            raise AgentChatException(f"Agent is not of the expected type {type(AzureAIAgent)}.")

        async for is_visible, message in AgentThreadActions.invoke(
            agent=agent,
            thread_id=self.thread_id,
            arguments=agent.arguments,
            kernel=agent.kernel,
            **kwargs,
        ):
            yield is_visible, message

    @override
    async def invoke_stream(
        self,
        agent: "Agent",
        messages: list["ChatMessageContent"],
        **kwargs,
    ) -> AsyncIterable["ChatMessageContent"]:
        """Invoke the agent stream.

View on GitHub (pinned to c028a0c7dc)

Solutions

1. Ensure every agent in an AgentGroupChat that shares a channel is an AzureAIAgent (or implement a compatible channel).
2. Use separate group chats or channels for different agent implementations.
3. Verify the agent object type before adding it to the chat.

Example fix

// before
chat = AgentGroupChat(azure_agent, chat_completion_agent)  // mixed types
// after
chat = AgentGroupChat(azure_agent_1, azure_agent_2)  // all AzureAIAgent

from semantic_kernel.agents.azure_ai.azure_ai_agent import AzureAIAgent
def assert_all_azure(agents):
    for a in agents:
        if not isinstance(a, AzureAIAgent):
            raise TypeError(f'{type(a).__name__} cannot join an AzureAI channel group chat')
    return agents

def is_azure_agent(agent) -> bool:
    from semantic_kernel.agents.azure_ai.azure_ai_agent import AzureAIAgent
    return isinstance(agent, AzureAIAgent)

try:
    async for msg in group_chat.invoke(): ...
except AgentChatException as e:
    if 'not of the expected type' in str(e):
        log.error('Group chat contains a non-AzureAIAgent')
    raise

When it happens

Trigger: Adding a ChatCompletionAgent or OpenAIAssistantAgent to an AgentGroupChat whose channel resolved to an AzureAIChannel; mixing agent types in a group chat where the first agent created an AzureAI channel and a later agent is incompatible; passing a mock/wrong agent in tests.

Common situations: Building a multi-agent group chat with heterogeneous agent types without ensuring they share a compatible channel; refactoring that swapped an AzureAIAgent for another type but kept the same channel; incorrect agent construction returning a base Agent.

Related errors

• Failed to delete thread: {e}
• Expected AzureAIAgentSettings, got {type(settings).__name__}
• Agent is not of the expected type {type(BedrockAgent)}.
• Agent is not of the expected type {type(OpenAIAssistantAgent
• Channel Keys must not be empty. Unable to generate channel h

AI-assisted analysis of microsoft/semantic-kernel@c028a0c7dc (2026-08-13). Data as JSON: /api/errors/f809206823f9a091. Report an issue: GitHub.