RouterStream

This docs was updated at: 2026-03-21

com.paragon.agents.RouterStream  ·  Class

---

Streaming wrapper for RouterAgent that provides event callbacks during routing and execution.

RouterStream first classifies the input, then executes the selected agent with streaming.

AgenticContext context = AgenticContext.create()
    .addMessage(Message.user("Help with billing"));
router.routeStream(context)
    .onRouteSelected(agent -> System.out.println("Routed to: " + agent.name()))
    .onTextDelta(System.out::print)
    .onComplete(result -> System.out.println("\nDone!"))
    .start();

Since: 1.0

Methods

onRouteSelected

public @NonNull RouterStream onRouteSelected(@NonNull Consumer<Interactable> callback)

Called when a route is selected.

Parameters

Name	Description
callback	receives the selected Interactable

Returns

this stream

---

onRoutingFailed

public @NonNull RouterStream onRoutingFailed(@NonNull Consumer<String> callback)

Called when no route is found for the input (empty input or no matching route).

Parameters

Name	Description
callback	receives a description of the routing failure

Returns

this stream

---

onTextDelta

public @NonNull RouterStream onTextDelta(@NonNull Consumer<String> callback)

Called for each text delta during streaming.

Parameters

Name	Description
callback	receives text chunks

Returns

this stream

---

onComplete

public @NonNull RouterStream onComplete(@NonNull Consumer<AgentResult> callback)

Called when streaming completes successfully.

Parameters

Name	Description
callback	receives the final result

Returns

this stream

---

onError

public @NonNull RouterStream onError(@NonNull Consumer<Throwable> callback)

Called when an error occurs.

Parameters

Name	Description
callback	receives the error

Returns

this stream

---

onTurnStart

public @NonNull RouterStream onTurnStart(@NonNull Consumer<Integer> callback)

Called at the start of each turn.

Parameters

Name	Description
callback	receives the turn number

Returns

this stream

---

onToolExecuted

public @NonNull RouterStream onToolExecuted(@NonNull Consumer<ToolExecution> callback)

Called when a tool execution completes.

Parameters

Name	Description
callback	receives the tool execution result

Returns

this stream

---

onHandoff

public @NonNull RouterStream onHandoff(@NonNull Consumer<Handoff> callback)

Called when a handoff occurs within the selected agent.

Parameters

Name	Description
callback	receives the handoff

Returns

this stream

---

onToolCallPending

public @NonNull RouterStream onToolCallPending(AgentStream.ToolConfirmationHandler handler)

Called when a tool call requires confirmation (human-in-the-loop), forwarded from the child agent.

Parameters

Name	Description
handler	receives the pending tool call and approval callback

Returns

this stream

---

onPause

public @NonNull RouterStream onPause(AgentStream.PauseHandler handler)

Called when the child agent should pause for async approval, forwarded from the child agent.

Parameters

Name	Description
handler	receives the serializable run state

Returns

this stream

---

onGuardrailFailed

public @NonNull RouterStream onGuardrailFailed(@NonNull Consumer<GuardrailResult.Failed> callback)

Called when an output guardrail fails in the child agent.

Parameters

Name	Description
callback	receives the failed guardrail result

Returns

this stream

---

onClientSideTool

public @NonNull RouterStream onClientSideTool(@NonNull Consumer<FunctionToolCall> callback)

Called when a client-side tool (stopsLoop = true) is detected in the child agent.

Parameters

Name	Description
callback	receives the tool call that triggered the exit

Returns

this stream

---

startBlocking

public @NonNull AgentResult startBlocking()

Starts the streaming router execution. Blocks until completion.

On virtual threads, blocking is efficient and does not consume platform threads.

Returns

the final result

---

start

public @NonNull AgentResult start()

Starts the streaming router execution. Blocks until completion.

On virtual threads, blocking is efficient and does not consume platform threads.

Returns

the final result