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Event reference

The following is a complete list of all possible Events that could appear in a Workflow Execution History.

Each Event corresponds to an enum that is defined in the Server API.

WorkflowExecutionStarted#

This is always the first Event in a Workflow Execution History and it indicates that the execution was invoked.

WorkflowExecutionCompleted#

This event type indicates that the Workflow Execution has successfully completed and contains Workflow Execution results.

WorkflowExecutionFailed#

This event type indicates that the Workflow execution has unsuccessfully completed and contains the Workflow execution error.

WorkflowExecutionTimedOut#

This event type indicates that the Workflow execution has timed out by the Temporal Server due to the Workflow having not been completed within timeout settings.

WorkflowExecutionCancelRequested#

This event type indicates that a request has been made to cancel the Workflow execution.

WorkflowExecutionCanceled#

This event type indicates that the client has confirmed the cancellation request and the Workflow execution has been cancelled.

WorkflowExecutionSignaled#

This event type indicates the Workflow has received a Signal event. The event type contains the Signal name, as well as a Signal payload.

WorkflowExecutionTerminated#

This event type indicates that the Workflow execution has been forcefully terminated and that likely the terminate Workflow API was called.

WorkflowExecutionContinuedAsNew#

This event type indicates that the Workflow has successfully completed and a new Workflow has been started within the same transaction. This event type contains last Workflow execution results as well as new Workflow execution inputs.

WorkflowTaskScheduled#

This event type indicates that the Workflow Task has been scheduled. The SDK client should now be able to process any new history events.

WorkflowTaskStarted#

This event type indicates that the Workflow Task has started. The SDK client has picked up the Workflow Task and is processing new history events.

WorkflowTaskCompleted#

This event type indicates that the Workflow Task completed. The SDK client picked up the Workflow Task, processed new history events, and may or may not ask the Temporal Server to do additional work. It is possible for the following events to still occur:

WorkflowTaskTimedOut#

This event type indicates that the Workflow Task encountered a timeout. Either an SDK client with a local cache was not available at the time, or it took too long for the SDK client to process the task.

WorkflowTaskFailed#

This event type indicates that the Workflow Task encountered a failure. Usually this means that the Workflow was non-deterministic. However, the Workflow reset functionality also uses this event.

ActivityTaskScheduled#

This event type indicates that an Activity Task was scheduled. The SDK client should pick up this activity task and execute. This event type contains activity inputs, as well as activity timeout configurations.

ActivityTaskStarted#

This event type indicates that the Activity Task has started executing. The SDK client has picked up the Activity Task and is processing the Activity invocation.

ActivityTaskCompleted#

This event type indicates that the Activity Task has completed. The SDK client has picked up and successfully completed the Activity Task. This event type contains Activity execution results.

ActivityTaskFailed#

This event type indicates that the Activity Task has completed. The SDK picked up the Activity Task but unsuccessfully completed it. This event type contains Activity execution errors.

ActivityTaskTimedOut#

This event type indicates that the Activity has timed out according to the Temporal Server, due to the Activity having not completed within the timeout settings.

ActivityTaskCancelRequested#

This event type indicates that a request to cancel the Activity has occurred. The SDK client will be able to confirm cancellation of an Activity during an Activity heartbeat.

ActivityTaskCanceled#

This event type indicates that the Activity has been cancelled.

TimerStarted#

This event type indicates a timer has started.

TimerFired#

This event type indicates a timer has fired.

TimerCanceled#

This event type indicates a Timer has been cancelled.

RequestCancelExternalWorkflowExecutionInitiated#

This event type indicates that a Workflow has requested that the Temporal Server try to cancel another Workflow.

RequestCancelExternalWorkflowExecutionFailed#

This event type indicates that Temporal Server could not cancel the targeted Workflow. This is usually because the target Workflow could not be found.

ExternalWorkflowExecutionCancelRequested#

This event type indicates that the Temporal Server has successfully requested the cancellation of the target Workflow.

ExternalWorkflowExecutionSignaled#

This event type indicates that the Temporal Server has successfully Signaled the targeted Workflow.

MarkerRecorded#

This event type is transparent to the Temporal Server. The Server will only store it and will not try to understand it. The SDK client may use it for local activities or side effects.

StartChildWorkflowExecutionInitiated#

This event type indicates that the Temporal Server will try to start a child Workflow.

StartChildWorkflowExecutionFailed#

This event type indicates a child Workflow execution cannot be started / triggered. It is usually due to a child Workflow ID collision.

ChildWorkflowExecutionStarted#

This event type indicates a child Workflow execution has successfully started / triggered. This would also cause the WorkflowExecutionStarted to be recorded for the Workflow that has started.

ChildWorkflowExecutionCompleted#

This event type indicates that the child Workflow execution has successfully completed. This would also cause the WorkflowExecutionCompleted to be recorded for the Workflow that has completed.

ChildWorkflowExecutionFailed#

This event type indicates that the child Workflow execution has unsuccessfully completed. This would also cause the WorkflowExecutionFailed to be recorded for the Workflow that has failed.

ChildWorkflowExecutionCanceled#

This event type indicates that the child Workflow execution has been cancelled. This would also cause the WorkflowExecutionCanceled to be recorded for the Workflow that was canceled.

ChildWorkflowExecutionTimedOut#

This event type indicates that the child Workflow execution has timed out by the Temporal Server. This would also cause the WorkflowExecutionTimeOut to be recorded for the Workflow that timed out.

ChildWorkflowExecutionTerminated#

This event type indicates that the child Workflow execution has been terminated. This would also cause the WorkflowExecutionTerminated to be recorded for the Workflow that was terminated.

SignalExternalWorkflowExecutionInitiated#

This event type indicates that the Temporal Server will try to Signal the targeted Workflow. This event type contains the Signal name, as well as a Signal payload.

SignalExternalWorkflowExecutionFailed#

This event type indicates that the Temporal Server cannot Signal the targeted Workflow, usually because the Workflow could not be found.

UpsertWorkflowSearchAttributes#

This event type indicates that the Workflow search attributes should be updated and synchronized with the visibility store.