Streaming¶

Every Agent exposes executeStream(...) returning a Flux<AgentEvent>. AgentGraph.invokeStream(...) does the same for whole graphs.

Subscribing¶

graph.invokeStream(AgentContext.of("hello"))
    .subscribe(event -> {
        switch (event) {
            case AgentEvent.Token t          -> System.out.print(t.chunk());
            case AgentEvent.NodeTransition x -> System.out.println("\n--> " + x.to());
            case AgentEvent.ToolCallStart s  -> System.out.println("[tool] " + s.toolName());
            case AgentEvent.ToolCallEnd e    -> System.out.println("[done] " + e.record().name());
            case AgentEvent.Completed c      -> System.out.println("\n[graph done]");
        }
    });

Event types¶

AgentEvent is a sealed interface with five cases:

Event	When
`Token(chunk)`	Each token (or chunk) streamed by the underlying LLM
`ToolCallStart(name, args)`	A tool/function is about to execute
`ToolCallEnd(record)`	A tool/function returned a result
`NodeTransition(from, to)`	The graph moves from one node to the next
`Completed(result)`	Terminal event — carries the final `AgentResult`

Use cases¶

Server-Sent Events to a browser (see agentflow4j-playground for a working example).
Live logging in CLI agents.
Cancellation: dispose the Disposable returned by subscribe to stop the run.