EventInterceptor tracks workflow and activity execution events for monitoring and observability. Automatically publishes events when workflows and activities start and end, including workflow state information. All activities automatically publish start/end events, and all workflows automatically publish start/end events with state. Events are published even if workflows or activities fail, and event publishing failures are logged but don't fail workflows.

EventInterceptor is part of the Interceptors system and can be combined with other interceptors.

EventInterceptor

Class

📁application_sdk.interceptors.events

Tracks workflow and activity execution events for monitoring and observability. Automatically publishes events when workflows and activities start and end, including workflow state information. All activities automatically publish start/end events, and all workflows automatically publish start/end events with state. Events are published even if workflows or activities fail, and event publishing failures are logged but don't fail workflows.

Methods1

▸

__init__

__init__(self)

Initialize EventInterceptor. No parameters required.

Usage Examples

Register EventInterceptor with worker

Register EventInterceptor to automatically track workflow and activity events

from temporalio.worker import Worker
from application_sdk.interceptors import EventInterceptor

worker = Worker(
  client,
  task_queue="my-task-queue",
  workflows=[MyWorkflow],
  activities=[my_activity],
  interceptors=[EventInterceptor()]
)

Event types

The EventInterceptor automatically publishes these event types:

Event Name	Event Type	When Published	Metadata
ACTIVITY_START	APPLICATION_EVENT	Before activity execution	None
ACTIVITY_END	APPLICATION_EVENT	After activity execution	None
WORKFLOW_START	APPLICATION_EVENT	Before workflow execution	workflow_state: RUNNING
WORKFLOW_END	APPLICATION_EVENT	After workflow execution	workflow_state: COMPLETED or FAILED

See also

• Interceptors: Overview of all interceptors and how to combine them
• RedisLockInterceptor: Manage distributed locks for activities using Redis
• CleanupInterceptor: Automatically clean up temporary artifacts and activity state
• Handle events: Event handling patterns in workflows