Question

I am using ag-ui, and on the frontend, I am building a chat UI with @ag-ui/client.
I have several questions about this process, but one of them concerns error handling.

When the API finishes normally, on_complete is called, and since this function takes AgentRunResult as a parameter, it’s easy to get the user’s input and the newly generated LLM messages. I use this callback to store messages in the database.

However, if an error occurs during API execution (especially when client.abortAgent is executed from the frontend), this callback is not triggered. I considered implementing a subclass of AGUIEventStream to handle errors, but I noticed that not all event objects have a result, only certain events have one, and these events appear to be generated from the graph.

Is there a way to collect the ModelRequest and ModelResponse up until just before the error occurs, even in cases of errors? If not, would I need to collect all events and manually construct ModelRequest and ModelResponse from them to achieve this?

Since a function that converts ag-ui messages into ModelMessage is already implemented(AGUIAdapter.load_messages), this isn’t a difficult task. However, I want to avoid handling event branching and collection twic, once on the frontend and again on the backend. I’m asking because there might be a better way that I’m unaware of.

Additional Context

No response