Events reference

Events

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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are created by the Temporal Cluster

What is a Temporal Cluster?

A Temporal Cluster is the Temporal Server paired with persistence.

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in response to external occurrences and Commands

What is a Command?

A Command is a requested action issued by a Worker to the Temporal Cluster after a Workflow Task Execution completes.

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generated by a Workflow Execution

What is a Workflow Execution?

A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application.

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. All possible Events that could appear in a Workflow Execution Event History

What is an Event History?

An append log of Events that represents the full state a Workflow Execution.

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are listed below.

WorkflowExecutionStarted

This is always the first Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

Learn more

in a Workflow Execution Event History. It indicates that the Cluster received a request to spawn the Workflow Execution.

Field	Description
workflow_type	The Name What is a Workflow Type? A Workflow Type is a name that maps to a Workflow Definition. Learn more of Workflow What is a Workflow? In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution. Learn more that was initiated.
parent_workflow_namespace	The Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Parent Workflow Execution What is a Workflow Execution? A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application. Learn more , if applicable.
parent_workflow_execution	Identifies the parent Workflow and the execution run.
parent_initiated_event_id	Id of the StartWorkflowExecutionInitiated Event this Event corresponds to.
task_queue	The Task Queue What is a Task Queue? A Task Queue is a first-in, first-out queue that a Worker Process polls for Tasks. Learn more that this Workflow Task What is a Workflow Task? A Workflow Task is a Task that contains the context needed to make progress with a Workflow Execution. Learn more was enqueued in.
input	Information that is deserialized by the SDK to provide arguments to the Workflow.
workflow_execution_timeout	The total timeout period for a Workflow Execution What is a Workflow Execution? A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application. Learn more , including retries and continue-as-new.
workflow_run_timeout	Timeout of a single Workflow run.
workflow_task_timeout	Timeout of a single Workflow Task.
continued_execution_run_id	Run Id What is a Run Id? A Run Id is a globally unique, platform-level identifier for a Workflow Execution. Learn more of the previous Workflow which continued-as-new, retried or was executed by Cron into this Workflow.
initiator	Allows the Workflow to continue as a new Workflow Execution.
continued_failure	Serialized result of a failure.
last_completion_result	Information from the previously completed Task What is a Task? A Task is the context needed to make progress with a specific Workflow Execution or Activity Execution. Learn more , if applicable.
original_execution_run_id	The Run Id What is a Run Id? A Run Id is a globally unique, platform-level identifier for a Workflow Execution. Learn more of the original Workflow started.
identity	Id of the Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more that requested the start of this Workflow.
first_execution_run_id	The first Run Id What is a Run Id? A Run Id is a globally unique, platform-level identifier for a Workflow Execution. Learn more , along the chain of Continue-As-New What is Continue-As-New? Continue-As-New is the mechanism by which all relevant state is passed to a new Workflow Execution with a fresh Event History. Learn more Runs and Reset.
retry_policy	The amount of retries as determined by the service's dynamic configuration. Retries will happen until 'schedule_to_close_timeout' is reached.
attempt	The number of attempts that have been made to complete this Task.
workflow_execution_expiration_time	The absolute time at which the Workflow Execution will time out What is a Workflow Execution Timeout? A Workflow Execution Timeout is the maximum time that a Workflow Execution can be executing (have an Open status) including retries and any usage of Continue As New. Learn more .
cron_schedule	Displays the Workflow's Cron Schedule What is a Temporal Cron Job? A Temporal Cron Job is the series of Workflow Executions that occur when a Cron Schedule is provided in the call to spawn a Workflow Execution. Learn more , if applicable.
first_workflow_task_backoff	Contains the amount of time between when this iteration of the Workflow was scheduled, and when it should run next. Applies to Cron Scheduling.
memo	Non-indexed information to show in the Workflow.
search_attributes	Provides data for setting up a Workflow's Search Attributes What is a Search Attribute? A Search Attribute is an indexed name used in List Filters to filter a list of Workflow Executions that have the Search Attribute in their metadata. Learn more .
prev_auto_reset_points
header	Information passed by the sender of the Signal What is a Signal? A Signal is an asynchronous request to a Workflow Execution. Learn more that is copied into the Workflow Task What is a Workflow Task? A Workflow Task is a Task that contains the context needed to make progress with a Workflow Execution. Learn more .

WorkflowExecutionCompleted

This indicates that the Workflow Execution

What is a Workflow Execution?

A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application.

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has successfully completed. The Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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contains Workflow Execution results.

Field	Description
result	Serialized result of completed Workflow What is a Workflow? In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution. Learn more .
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event was reported with.
new_execution_run_id	The Run Id What is a Run Id? A Run Id is a globally unique, platform-level identifier for a Workflow Execution. Learn more of the new Workflow Execution started as a result of a Cron Schedule What is a Temporal Cron Job? A Temporal Cron Job is the series of Workflow Executions that occur when a Cron Schedule is provided in the call to spawn a Workflow Execution. Learn more .

WorkflowExecutionFailed

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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indicates that the Workflow Execution

What is a Workflow Execution?

A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application.

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has unsuccessfully completed and contains the Workflow Execution error.

Field	Description
failure	Serialized result of a Workflow What is a Workflow? In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution. Learn more failure.
retry_state	The reason provided for whether the Task What is a Task? A Task is the context needed to make progress with a specific Workflow Execution or Activity Execution. Learn more should or shouldn't be retried.
workflow_task_completed_event_id	The Run Id What is a Run Id? A Run Id is a globally unique, platform-level identifier for a Workflow Execution. Learn more of the WorkflowTaskCompleted that the Event was reported with.
new_execution_run_id	The Run Id What is a Run Id? A Run Id is a globally unique, platform-level identifier for a Workflow Execution. Learn more of the new Workflow started by Cron or Retry What is a Retry Policy? A Retry Policy is a collection of attributes that instructs the Temporal Server how to retry a failure of a Workflow Execution or an Activity Task Execution. Learn more .

WorkflowExecutionTimedOut

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Workflow Execution

What is a Workflow Execution?

A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application.

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has timed out by the Temporal Server

What is the Temporal Server?

The Temporal Server is a grouping of four horizontally scalable services.

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due to the Workflow

What is a Workflow?

In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution.

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having not been completed within timeout

What is a Workflow Execution Timeout?

A Workflow Execution Timeout is the maximum time that a Workflow Execution can be executing (have an Open status) including retries and any usage of Continue As New.

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settings.

Field	Description
retry_state	The reason provided for whether the Task What is a Task? A Task is the context needed to make progress with a specific Workflow Execution or Activity Execution. Learn more should or shouldn't be retried.
new_execution_run_id	The Run Id What is a Run Id? A Run Id is a globally unique, platform-level identifier for a Workflow Execution. Learn more of the new Workflow started by Cron or Retry What is a Retry Policy? A Retry Policy is a collection of attributes that instructs the Temporal Server how to retry a failure of a Workflow Execution or an Activity Task Execution. Learn more .

WorkflowExecutionCancelRequested

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that a request has been made to cancel the Workflow Execution

What is a Workflow Execution?

A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application.

Learn more

.

Field	Description
cause	The user-provided reason for the cancelation request.
external_initiated_event_id	The Run Id What is a Run Id? A Run Id is a globally unique, platform-level identifier for a Workflow Execution. Learn more of the Event in the Workflow What is a Workflow? In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution. Learn more that requested cancelation, if applicable.
external_workflow_execution	Identifies the external Workflow and the run of the its execution.
identity	Id of the Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more that requested cancelation.

WorkflowExecutionCanceled

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the client has confirmed the cancelation request and the Workflow Execution

What is a Workflow Execution?

A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application.

Learn more

has been canceled.

Field	Description
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event was reported with.
details	Additional information reported by the Workflow What is a Workflow? In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution. Learn more upon cancelation.

WorkflowExecutionSignaled

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates the Workflow

What is a Workflow?

In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution.

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has received a Signal

What is a Signal?

A Signal is an asynchronous request to a Workflow Execution.

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Event. The Event type contains the Signal name, as well as a Signal payload.

Field	Description
signal_name	The name/type of Signal to be fired.
input	Information that is deserialized by the SDK to provide arguments to the Workflow function.
identity	Identifies the Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more that signaled to the Workflow.
header	Information passed by the sender of the Signal that is copied into the Workflow Task What is a Workflow Task? A Workflow Task is a Task that contains the context needed to make progress with a Workflow Execution. Learn more .

WorkflowExecutionTerminated

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Workflow Execution

What is a Workflow Execution?

A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application.

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has been forcefully terminated and that likely the terminate Workflow API was called.

Field	Description
reason	Information provided by the user or client for Workflow termination.
details	Additional information reported by the Workflow upon termination.
identity	Identifies the Worker that requested termination.

WorkflowExecutionContinuedAsNew

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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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

What is a Workflow Execution?

A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application.

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results as well as new Workflow Execution inputs.

Field	Description
new_execution_run_id	The Run Id What is a Run Id? A Run Id is a globally unique, platform-level identifier for a Workflow Execution. Learn more of the new Workflow started by this Continue-As-New Event.
workflow_type	The name/type of Workflow that was started by this Event.
task_queue	The Task Queue What is a Task Queue? A Task Queue is a first-in, first-out queue that a Worker Process polls for Tasks. Learn more that this Workflow Task What is a Workflow Task? A Workflow Task is a Task that contains the context needed to make progress with a Workflow Execution. Learn more was enqueued in.
input	Information that is deserialized by the SDK to provide arguments to the Workflow.
workflow_run_timeout	Timeout of a single Workflow run.
workflow_task_timeout	Timeout of a single Workflow Task.
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event command was reported with.
backoff_start_interval	The amount of time to delay the beginning of the ContinuedAsNew Workflow.
initiator	Allows the Workflow to continue as a new execution.
last_completion_result	Information passed by the previously completed Task to the ongoing execution.
header	Information passed by the sender of the Signal that is copied into the Workflow Task.
memo	Non-indexed information to show in the Workflow.
search_attributes	Provides data for setting up a Workflow's Search Attributes What is a Search Attribute? A Search Attribute is an indexed name used in List Filters to filter a list of Workflow Executions that have the Search Attribute in their metadata. Learn more .

WorkflowTaskScheduled

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Workflow Task

What is a Workflow Task?

A Workflow Task is a Task that contains the context needed to make progress with a Workflow Execution.

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has been scheduled. The SDK client should now be able to process any new history events.

Field	Description
task_queue	The Task Queue What is a Task Queue? A Task Queue is a first-in, first-out queue that a Worker Process polls for Tasks. Learn more that this Workflow Task was enqueued in.
start_to_close_timeout	The time that the Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more takes to process this Task once it's received.
attempt	The number of attempts that have been made to complete this Task.

WorkflowTaskStarted

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Workflow Task

What is a Workflow Task?

A Workflow Task is a Task that contains the context needed to make progress with a Workflow Execution.

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has started. The SDK client has picked up the Workflow Task and is processing new history events.

Field	Description
scheduled_event_id	The Id of the WorkflowTaskScheduled Event that this Workflow Task corresponds to.
identity	Identifies the Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more that started this Task.
request_id	Identifies the Workflow Task request.

WorkflowTaskCompleted

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Workflow Task

What is a Workflow Task?

A Workflow Task is a Task that contains the context needed to make progress with a Workflow Execution.

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completed.

Field	Description
scheduled_event_id	The Id of the WorkflowTaskScheduled Event that this Workflow Task corresponds to.
started_event_id	The Id of the WorkflowTaskStarted Event that this Task corresponds to.
identity	Identity of the Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more that completed this Task.
binary_checksum	Binary Id of the Worker that completed this Task.

The SDK client picked up the Workflow Task, processed new history events, and may or may not ask the Temporal Server

What is the Temporal Server?

The Temporal Server is a grouping of four horizontally scalable services.

Learn more

to do additional work. It is possible for the following events to still occur:

• ActivityTaskScheduled
• TimerStarted
• UpsertWorkflowSearchAttributes
• MarkerRecorded
• StartChildWorkflowExecutionInitiated
• RequestCancelExternalWorkflowExecutionInitiated
• SignalExternalWorkflowExecutionInitiated
• WorkflowExecutionCompleted
• WorkflowExecutionFailed
• WorkflowExecutionCanceled
• WorkflowExecutionContinuedAsNew

WorkflowTaskTimedOut

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Workflow Task

What is a Workflow Task?

A Workflow Task is a Task that contains the context needed to make progress with a Workflow Execution.

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encountered a timeout

What is a Workflow Task Timeout?

A Workflow Task Timeout is the maximum amount of time that the Temporal Server will wait for a Worker to start processing a Workflow Task after the Task has been pulled from the Task Queue.

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. 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.

Field	Description
scheduled_event_id	The Id of the WorkflowTaskScheduled Event that this Workflow Task corresponds to.
started_event_id	The Id of the WorkflowTaskStarted Event that this Task corresponds to.
timeout_type	The type of timeout that has occurred.

WorkflowTaskFailed

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Workflow Task

What is a Workflow Task?

A Workflow Task is a Task that contains the context needed to make progress with a Workflow Execution.

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encountered a failure. Usually this means that the Workflow was non-deterministic. However, the Workflow reset functionality also uses this Event.

Field	Description
scheduled_event_id	The Id of the WorkflowTaskScheduled Event that this Workflow Task corresponds to.
started_event_id	The Id of the WorkflowTaskStarted Event that this Workflow Task corresponds to.
failure	Details for the Workflow Task's failure.
identity	The identity of the Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more that failed this Task. The Worker must be explicitly defined to return a value for this field.
base_run_id	The original Run Id What is a Run Id? A Run Id is a globally unique, platform-level identifier for a Workflow Execution. Learn more of the Workflow.
new_run_id	The Run Id of the reset Workflow.
fork_event_version	Identifies the Event version that was forked off to the reset Workflow.
binary_checksum	The Binary Id of the Worker that failed this Task. The Worker must be explicitly defined to return a value for this field.

ActivityTaskScheduled

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that an Activity Task

What is an Activity Task?

An Activity Task contains the context needed to make an Activity Task Execution.

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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.

Field	Description
activity_id	The identifier assigned to this Activity by a Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more or user.
activity_type	The type of Activity What is an Activity Type? An Activity Type is the mapping of a name to an Activity Definition. Learn more that was scheduled.
namespace	Namespace of the Workflow that the Activity What is an Activity? In day-to-day conversations, the term "Activity" frequently denotes either an Activity Type, an Activity Definition, or an Activity Execution. Learn more resides in.
task_queue	The Task Queue What is a Task Queue? A Task Queue is a first-in, first-out queue that a Worker Process polls for Tasks. Learn more that this Activity Task was enqueued in.
header	Information passed by the sender of the Signal What is a Signal? A Signal is an asynchronous request to a Workflow Execution. Learn more that is copied into the Workflow Task What is a Workflow Task? A Workflow Task is a Task that contains the context needed to make progress with a Workflow Execution. Learn more .
input	Information that is deserialized by the SDK to provide arguments to the Workflow What is a Workflow? In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution. Learn more function.
schedule_to_close_timeout	The amount of time that a caller will wait for Activity completion. Limits the amount of time that retries will be attempted for this Activity.
schedule_to_start_timeout	Limits the time that an Activity Task can stay in a Task Queue. This timeout cannot be retried.
start_to_close_timeout	Maximum amount of execution time that an Activity is allowed after being picked up by a Worker. This timeout is retryable.
heartbeat_timeout	Maximum amount of time allowed between successful Worker heartbeats.
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event was reported with.
retry_policy	The amount of retries as determined by the service's dynamic configuration. Retries will happen until schedule_to_close_timeout is reached.

ActivityTaskStarted

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Activity Task

What is an Activity Task?

An Activity Task contains the context needed to make an Activity Task Execution.

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has started executing. The SDK client has picked up the Activity Task and is processing the Activity

What is an Activity?

In day-to-day conversations, the term "Activity" frequently denotes either an Activity Type, an Activity Definition, or an Activity Execution.

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invocation.

Field	Description
scheduled_event_id	The Id of the ActivityTaskScheduled Event that this Task corresponds to.
identity	Identifies the Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more that started the Task.
request_id	Identifies the Activity Task request.
attempt	The number of attempts that have been made to complete this Task.
last_failure	Details from the most recent failure Event. Only assigned values if the Task has previously failed and been retried.

ActivityTaskCompleted

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Activity Task

What is an Activity Task?

An Activity Task contains the context needed to make an Activity Task Execution.

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has completed. The SDK client has picked up and successfully completed the Activity Task. This Event type contains Activity Execution

What is an Activity Execution?

An Activity Execution is the full chain of Activity Task Executions.

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results.

Field	Description
result	Serialized result of a completed Activity What is an Activity? In day-to-day conversations, the term "Activity" frequently denotes either an Activity Type, an Activity Definition, or an Activity Execution. Learn more .
scheduled_event_id	The Id of the ActivityTaskScheduled Event that this completion Event corresponds to.
started_event_id	The Id of the ActivityTaskStarted Event that this Task corresponds to.
identity	Identity of the Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more that completed this Task.

ActivityTaskFailed

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Activity Task

What is an Activity Task?

An Activity Task contains the context needed to make an Activity Task Execution.

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has completed. The SDK picked up the Activity Task but unsuccessfully completed it. This Event type contains Activity Execution

What is an Activity Execution?

An Activity Execution is the full chain of Activity Task Executions.

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errors.

Field	Description
failure	Serialized result of a Workflow What is a Workflow? In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution. Learn more failure.
scheduled_event_id	The Id of the ActivityTaskScheduled Event that this failure Event corresponds to.
started_event_id	The Id of the ActivityTaskStarted Event that this failure corresponds to.
retry_state	The reason provided for whether the Task should or shouldn't be retried.

ActivityTaskTimedOut

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Activity has timed out according to the Temporal Server

What is the Temporal Server?

The Temporal Server is a grouping of four horizontally scalable services.

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, due to the Activity

What is an Activity?

In day-to-day conversations, the term "Activity" frequently denotes either an Activity Type, an Activity Definition, or an Activity Execution.

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having not completed within the timeout settings.

Field	Description
failure	Serialized result of a Workflow What is a Workflow? In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution. Learn more failure.
scheduled_event_id	The Id of the ActivityTaskScheduled Event that this timeout Event corresponds to.
started_event_id	The Id of the ActivityTaskStarted Event that this timeout corresponds to.
retry_state	The reason provided for whether the Task should or shouldn't be retried.

ActivityTaskCancelRequested

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that a request to cancel the Activity

What is an Activity?

In day-to-day conversations, the term "Activity" frequently denotes either an Activity Type, an Activity Definition, or an Activity Execution.

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has occurred. The SDK client will be able to confirm cancelation of an Activity during an Activity heartbeat.

Field	Description
scheduled_event_id	The Id of the ActivityTaskScheduled Event that this cancel Event corresponds to.
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event was reported with.

ActivityTaskCanceled

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Activity

What is an Activity?

In day-to-day conversations, the term "Activity" frequently denotes either an Activity Type, an Activity Definition, or an Activity Execution.

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has been canceled.

Field	Description
details	Additional information reported by the Activity upon confirming cancelation.
latest_cancel_requested_event_id	Id of the most recent ActivityTaskCancelRequested Event which refers to the same Activity.
scheduled_event_id	The Id of the ActivityTaskScheduled Event that this cancelation corresponds to.
started_event_id	The Id of the ActivityTaskStarted Event that this cancelation corresponds to.
identity	Identifies the Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more that requested cancelation.

TimerStarted

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates a timer has started.

Field	Description
timer_id	The Id assigned for the timer by a Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more or user.
start_to_fire_timeout	Amount of time to elapse before the timer fires.
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event was reported with.

TimerFired

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates a timer has fired.

Field	Description
timer_id	The Id assigned for the timer by a Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more or user.
started_event_id	The Id of the TimerStarted Event itself.

TimerCanceled

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates a Timer has been canceled.

Field	Description
timer_id	The Id assigned for the timer by a Worker What is a Worker? In day-to-day conversations, the term Worker is used to denote both a Worker Program and a Worker Process. Temporal documentation aims to be explicit and differentiate between them. Learn more or user.
started_event_id	The Id of the TimerStarted Event itself.
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event was reported with.

RequestCancelExternalWorkflowExecutionInitiated

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that a Workflow

What is a Workflow?

In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution.

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has requested that the Temporal Server

What is the Temporal Server?

The Temporal Server is a grouping of four horizontally scalable services.

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try to cancel another Workflow.

Field	Description
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event was reported with.
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Workflow that`s going to be signaled for execution.
workflow_execution	Identifies the Workflow and the run of the Workflow Execution What is a Workflow Execution? A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application. Learn more .
child_workflow_only	Set to true if this Workflow is a child of the Workflow which issued the cancelation request.
reason	Information provided by the user or client for Workflow cancelation.

RequestCancelExternalWorkflowExecutionFailed

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that Temporal Server

What is the Temporal Server?

The Temporal Server is a grouping of four horizontally scalable services.

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could not cancel the targeted Workflow

What is a Workflow?

In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution.

Learn more

. This is usually because the target Workflow could not be found.

Field	Description
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event was reported with.
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Workflow that failed to cancel.
workflow_execution	Identifies the Workflow and the run of the Workflow Execution What is a Workflow Execution? A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application. Learn more .
initiated_event_id	Id of the [RequestCancelExternalWorkflowExecutionInitiated] Event this failure corresponds to.

ExternalWorkflowExecutionCancelRequested

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Temporal Server

What is the Temporal Server?

The Temporal Server is a grouping of four horizontally scalable services.

Learn more

has successfully requested the cancelation of the target Workflow

What is a Workflow?

In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution.

Learn more

.

Field	Description
initiated_event_id	Id of the RequestCancelExternalWorkflowExecutionInitiated Event that this cancelation request corresponds to.
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Workflow that was requested to cancel.
workflow_execution	Identifies the Workflow and the run of the Workflow Execution What is a Workflow Execution? A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application. Learn more .

ExternalWorkflowExecutionSignaled

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Temporal Server

What is the Temporal Server?

The Temporal Server is a grouping of four horizontally scalable services.

Learn more

has successfully Signaled

What is a Signal?

A Signal is an asynchronous request to a Workflow Execution.

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the targeted Workflow

What is a Workflow?

In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution.

Learn more

.

Field	Description
initiated_event_id	Id of the SignalExternalWorkflowExecutionInitiated Event this Event corresponds to.
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Workflow that was signaled to.
workflow_execution	Identifies the Workflow and the run of the Workflow Execution What is a Workflow Execution? A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application. Learn more .

MarkerRecorded

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type is transparent to the Temporal Server

What is the Temporal Server?

The Temporal Server is a grouping of four horizontally scalable services.

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. 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.

Field	Description
marker_name	Identifies various markers.
details	Serialized information recorded in the marker.
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event was reported with.
header	Information passed by the sender of the Signal What is a Signal? A Signal is an asynchronous request to a Workflow Execution. Learn more that is copied into the marker.
failure	Serialized result of a Workflow What is a Workflow? In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution. Learn more failure.

StartChildWorkflowExecutionInitiated

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Temporal Server

What is the Temporal Server?

The Temporal Server is a grouping of four horizontally scalable services.

Learn more

will try to start a Child Workflow.

Field	Description
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Child Workflow.
workflow_id	Identifies the Child Workflow.
workflow_type	The name/type of Workflow that was initiated.

StartChildWorkflowExecutionFailed

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates a Child Workflow Execution

What is a Child Workflow Execution?

A Child Workflow Execution is a Workflow Execution that is spawned from within another Workflow.

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cannot be started / triggered. It is usually due to a Child Workflow Id collision.

Field	Description
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Child Workflow.
workflow_id	Identifies the Child Workflow.
workflow_type	The name/type of Workflow that has failed.
initiated_event_id	Id of the StartChildWorkflowExecutionInitiated Event this Event corresponds to.
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event was reported with.

ChildWorkflowExecutionStarted

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates a Child Workflow Execution

What is a Child Workflow Execution?

A Child Workflow Execution is a Workflow Execution that is spawned from within another Workflow.

Learn more

has successfully started / triggered. This would also cause the WorkflowExecutionStarted to be recorded for the Workflow that has started.

Field	Description
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Child Workflow.
initiated_event_id	Id of the StartChildWorkflowExecutionInitiated Event this Event corresponds to.
workflow_execution	Identifies the Workflow and the run of the Workflow Execution.
workflow_type	The name/type of Workflow that has started execution.
header	Information passed by the sender of the Signal What is a Signal? A Signal is an asynchronous request to a Workflow Execution. Learn more that is copied into the Child Workflow Task.

ChildWorkflowExecutionCompleted

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Child Workflow Execution

What is a Child Workflow Execution?

A Child Workflow Execution is a Workflow Execution that is spawned from within another Workflow.

Learn more

has successfully completed. This would also cause the WorkflowExecutionCompleted to be recorded for the Workflow

What is a Workflow?

In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution.

Learn more

that has completed.

Field	Description
result	Serialized result of the completed Child Workflow.
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the completed Child Workflow.
workflow_execution	Identifies the Workflow and the run of the Workflow Execution What is a Workflow Execution? A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application. Learn more .
workflow_type	The name/type of Workflow that was completed.
initiated_event_id	Id of the StartChildWorkflowExecutionInitiated Event this Event corresponds to.
started_event_id	Id of the ChildWorkflowExecutionStarted Event this Event corresponds to.

ChildWorkflowExecutionFailed

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Child Workflow Execution

What is a Child Workflow Execution?

A Child Workflow Execution is a Workflow Execution that is spawned from within another Workflow.

Learn more

has unsuccessfully completed. This would also cause the WorkflowExecutionFailed to be recorded for the Workflow that has failed.

Field	Description
failure	Serialized result of a Workflow What is a Workflow? In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution. Learn more failure.
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Child Workflow that failed.
workflow_execution	Identifies the Workflow and the run of the Workflow Execution What is a Workflow Execution? A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application. Learn more .
workflow_type	The name/type of Workflow that has failed.
initiated_event_id	Id of the StartChildWorkflowExecutionInitiated Event this Event corresponds to.
started_event_id	Id of the ChildWorkflowExecutionStarted Event this failure corresponds to.
retry_state	The reason provided for whether the Task should or shouldn't be retried.

ChildWorkflowExecutionCanceled

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Child Workflow Execution has been canceled. This would also cause the WorkflowExecutionCanceled to be recorded for the Workflow that was canceled.

Field	Description
details	Additional information reported by the Child Workflow upon cancelation.
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Child Workflow that was canceled.
workflow_execution	Identifies the Workflow and the run of the Workflow Execution What is a Workflow Execution? A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application. Learn more .
workflow_type	The name/type of Workflow that was canceled.
initiated_event_id	Id of the StartChildWorkflowExecutionInitiated Event this Event corresponds to.
started_event_id	Id of the ChildWorkflowExecutionStarted Event this cancelation corresponds to.

ChildWorkflowExecutionTimedOut

This Event type indicates that the Child Workflow Execution

What is a Child Workflow Execution?

A Child Workflow Execution is a Workflow Execution that is spawned from within another Workflow.

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has timed out by the Temporal Server

What is the Temporal Server?

The Temporal Server is a grouping of four horizontally scalable services.

Learn more

. This would also cause the WorkflowExecutionTimeOut to be recorded for the Workflow that timed out.

Field	Description
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Child Workflow.
workflow_execution	Identifies the Workflow and the run of the Workflow Execution.
workflow_type	The name/type of Workflow that has timed out.
initiated_event_id	Id of the StartChildWorkflowExecutionInitiated Event this Event corresponds to.
started_event_id	Id of the ChildWorkflowExecutionStarted Event that this timeout corresponds to.
retry_state	The reason provided for whether the Task should or shouldn't be retried.

ChildWorkflowExecutionTerminated

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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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.

Field	Description
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Child Workflow.
workflow_execution	Identifies the Workflow and the run of the Workflow Execution.
workflow_type	The name/type of Workflow that was terminated.
initiated_event_id	Id of the StartChildWorkflowExecutionInitiated Event this Event corresponds to.
started_event_id	Id of the ChildWorkflowExecutionStarted Event that this termination corresponds to.
retry_state	The reason provided for whether the Task should or shouldn't be retried.

SignalExternalWorkflowExecutionInitiated

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Temporal Server

What is the Temporal Server?

The Temporal Server is a grouping of four horizontally scalable services.

Learn more

will try to Signal

What is a Signal?

A Signal is an asynchronous request to a Workflow Execution.

Learn more

the targeted Workflow

What is a Workflow?

In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution.

Learn more

. This Event type contains the Signal name, as well as a Signal payload.

Field	Description
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event was reported with.
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Workflow that's to be signaled.
workflow_execution	Identifies the Workflow and the run of the Workflow Execution What is a Workflow Execution? A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application. Learn more .
signal_name	The name/type of Signal to be fired.
input	Information that is deserialized by the SDK to provide arguments to the Workflow Function.
child_workflow_only	Set to true if this Workflow is a child of the Workflow which issued the cancelation request.
header	Information to be passed from the Signal to the targeted Workflow.

SignalExternalWorkflowExecutionFailed

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Temporal Server

What is the Temporal Server?

The Temporal Server is a grouping of four horizontally scalable services.

Learn more

cannot Signal the targeted Workflow

What is a Workflow?

In day-to-day conversations, the term "Workflow" frequently denotes either a Workflow Type, a Workflow Definition, or a Workflow Execution.

Learn more

, usually because the Workflow could not be found.

Field	Description
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event was reported with.
namespace	Namespace What is a Namespace? A Namespace is a unit of isolation within the Temporal Platform Learn more of the Workflow that failed to execute.
workflow_execution	Identifies the Workflow and the run of the Workflow Execution What is a Workflow Execution? A Temporal Workflow Execution is a durable, scalable, reliable, and reactive function execution. It is the main unit of execution of a Temporal Application. Learn more .
initiated_event_id	Id of the RequestCancelExternalWorkflowExecutionInitiated Event this failure signal What is a Signal? A Signal is an asynchronous request to a Workflow Execution. Learn more corresponds to.

UpsertWorkflowSearchAttributes

This Event

What is an Event?

Events are created by the Temporal Cluster in response to external occurrences and Commands generated by a Workflow Execution.

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type indicates that the Workflow Search Attributes

What is a Search Attribute?

A Search Attribute is an indexed name used in List Filters to filter a list of Workflow Executions that have the Search Attribute in their metadata.

Learn more

should be updated and synchronized with the visibility store.

Field	Description
workflow_task_completed_event_id	The Id of the WorkflowTaskCompleted that the Event was reported with.
search_attributes	Provides data for setting up a Workflow`s Search Attributes What is a Search Attribute? A Search Attribute is an indexed name used in List Filters to filter a list of Workflow Executions that have the Search Attribute in their metadata. Learn more .