Streaming and lifecycle events

Use stream(DeepRequest) for a cold run and resumeStream(threadId, decisions) after an approval. Both return a Flow.Publisher<DeepEvent> and finish with Completed, Interrupted, or Failed. If the configured model implements StreamingChatModel, the same stream carries incremental TextDelta events; non-streaming models still publish the remaining lifecycle events.

agent.stream(new DeepRequest("research-42", "Summarize the workspace findings."))
        .subscribe(new Flow.Subscriber<DeepEvent>() {
            public void onSubscribe(Flow.Subscription subscription) { subscription.request(Long.MAX_VALUE); }
            public void onNext(DeepEvent event) { render(event); }
            public void onError(Throwable error) { report(error); }
            public void onComplete() { }
        });

DeepEvent makes the lifecycle observable without depending on a provider-specific event format:

Event	Meaning
`TextDelta`	Incremental assistant text from a streaming model turn.
`Message`	A complete assistant model message.
`ToolCallRequested` / `ToolResult`	A tool call and its resulting message.
`TodosUpdated`	The durable task plan changed.
`ContextOffloaded`	A large tool result was preserved in the workspace.
`SubagentStarted` / `SubagentCompleted`	A delegated task started or returned its report.
`ApprovalRequested`	One or more sensitive actions need a decision.
`Completed` / `Interrupted` / `Failed`	The terminal outcome.

For separate nested-agent observability, subscribe to agent.childStreams(). Each DeepAgentChildStream provides its own event publisher plus focused message, tool-call, output, and nested-child publishers.

Normal invoke and resume also create internal graph checkpoints. Use history(threadId) to inspect those checkpoints; a pending approval is represented as a durable graph interrupt. See context management for long-running conversation limits.