About the integration of AG-UI protocol

[DavdGao]

We've reviewed the AG-UI protocol as mentioned, but the integration advantages remain unclear. With my frontend design expertise, I'd like to propose a community-wide discussion to explore this together.

[DavdGao]

In my view, a potential approach to integrate AG-UI would be to post-process the content blocks within the generated Msg objects and wrap them with their corresponding AG-UI event types, such as text block, tool_use, and tool_result block.

For example:

@app.endpoint()
async def agent_endpoint() -> AsyncGenerator[Msg, None]:
    ...
    yield msg

In the app.endpoint implementation, when we receive the Msg object, we would extract its content blocks and wrap each one with the appropriate AG-UI event wrapper. It doesn't seem difficult.

However, there are some challenges with this approach:

• The TextMessageStart event only supports predefined roles: "developer", "system", "assistant", "user", and "tool". This raises the question of how to properly represent multi-agent conversations. In AgentScope, we use a name field to distinguish between different agents/entities, which doesn't directly map to AG-UI's role-based system.

[ljiufa]

It is already on the official roadmap

[ljiufa]

There are two problems to be solved

1. State Management

The registered state data structure of ReActAgent is fixed, and there needs to be a state that allows users to customize

2. Frontend Tools(External Tools)

Model should be able to call a tool that should not or cannot be executed during the same agent run inside the same Python process，agentScope should support the registration of tools that are not executed in the agent only

Could it be considered to add an external type of tool that is not actually executed in the agent? If Msg is tool_use, it indicates that the current tool call has ended, If possible, I am willing to submit a PR

- source: Literal["function", "mcp_server", "function_group"]
+ source: Literal["function", "mcp_server", "function_group", "external"]

For example, registering external tools

toolkit.register_tool_function(
    json_schema={
        "type": "function",
        "function": {
            "name": "change_background",
            "parameters": {
                "type": "object",
                "properties": {
                    "background": {
                        "type": "string",
                        "description": "background color",
                    }
                },
                "required": ["background"],
            },
            "description": "Change the background color of the chat. Can be anything that the CSS background attribute accepts. Regular colors, linear of radial gradients etc.",
        },
    }
)