Event Processors

You can enrich events with additional data by adding your own event processors, either on the scope level or globally. Though event processors are similar to before_send and before_send_transaction, there are two key differences:

• Event processors added with either add_global_event_processor or scope.add_event_processor run in an undetermined order, which means changes to the event may still be made after the event processor runs. before_send and before_send_transaction are guaranteed to be run last, after all other event processors, (which means they get the final version of the event right before it's sent, hence the name).
• While before_send, before_send_transaction, and processors added with add_global_event_processor run globally, regardless of scope, processors added with scope.add_event_processor only run on events captured while that scope is active.

Like before_send and before_send_transaction, event processors are passed two arguments, the event itself and a hint object containing extra metadata.

Event processors added to the global scope will run on every event sent after they've been added.

import sentry_sdk
from sentry_sdk.types import Event, Hint
from sentry_sdk.scope import add_global_event_processor

sentry_sdk.init(
  # ...
)

def event_processor(event, hint):
    event["tags"] = {"foo": "42"}
    return event

global_scope = sentry_sdk.get_global_scope()
global_scope.add_event_processor(event_processor)

# You can do the same thing using add_global_event_processor
add_global_event_processor(event_processor)

Event processors added to a local scope using new_scope or isolation_scope will only apply to events captured inside that scope.

with sentry_sdk.new_scope() as scope:
    scope.add_event_processor(event_processor)

    # The processor applies only inside this scope
    sentry_sdk.capture_message("Test")

# The event processor will NOT apply to this event
sentry_sdk.capture_message("Test");