Class A2ATaskInterruptedException

java.lang.Object

java.lang.Throwable

java.lang.Exception

java.lang.RuntimeException

dev.langchain4j.exception.LangChain4jException

dev.langchain4j.agentic.a2a.A2ATaskInterruptedException

All Implemented Interfaces:

Serializable

public class A2ATaskInterruptedException
extends LangChain4jException

Thrown when an A2A task enters an interrupted state (input-required or auth-required) instead of completing.

The remote agent has paused the task and is waiting for additional input or authentication before it can continue. The A2A server will not advance the task on its own, so the CompletableFuture backing the invocation is completed exceptionally with this exception rather than left pending indefinitely.

Since:

1.19.0

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
A2ATaskInterruptedException(String taskId, String contextId, org.a2aproject.sdk.spec.TaskState state, String reason)
A2ATaskInterruptedException(String taskId, org.a2aproject.sdk.spec.TaskState state, String reason)

Method Summary

Modifier and Type	Method	Description
String	contextId()	The id of the context containing the interrupted task.
static A2ATaskInterruptedException	from(AgenticScope scope, String responseId)	Reconstructs the A2A interruption associated with a pending response in an agentic scope.
String	reason()	The status message sent by the remote agent when it interrupted the task — typically the question asking for the missing input, or the authentication challenge.
org.a2aproject.sdk.spec.TaskState	state()	The interrupted state the task is in, either TASK_STATE_INPUT_REQUIRED or TASK_STATE_AUTH_REQUIRED.
String	taskId()	The id of the task that was interrupted.

Methods inherited from class Throwable

addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

A2ATaskInterruptedException

public A2ATaskInterruptedException(String taskId,
 org.a2aproject.sdk.spec.TaskState state,
 String reason)

A2ATaskInterruptedException

public A2ATaskInterruptedException(String taskId,
 String contextId,
 org.a2aproject.sdk.spec.TaskState state,
 String reason)

Method Details

taskId

public String taskId()

The id of the task that was interrupted.

Since:

1.19.0

contextId

public String contextId()

The id of the context containing the interrupted task. This can be used together with taskId() when sending the input or authentication needed to resume the task.

Since:

1.19.0

state

public org.a2aproject.sdk.spec.TaskState state()

The interrupted state the task is in, either TASK_STATE_INPUT_REQUIRED or TASK_STATE_AUTH_REQUIRED.

Since:

1.19.0

reason

public String reason()

The status message sent by the remote agent when it interrupted the task — typically the question asking for the missing input, or the authentication challenge. Returns null when the remote agent interrupted the task without sending one; the generic description used in Throwable.getMessage() in that case is not reported here, so callers can tell the two apart.

Since:

1.19.0

from

public static A2ATaskInterruptedException from(AgenticScope scope,
 String responseId)

Reconstructs the A2A interruption associated with a pending response in an agentic scope. This allows an external event handler to publish the remote task details before completing the pending response asynchronously.

Parameters:

scope - the suspended agentic scope

responseId - the pending response identifier

Returns:

the matching A2A task interruption

Throws:

IllegalArgumentException - if the response does not belong to an interrupted A2A task

Since:

1.19.0