Filtering events

You can filter out or customize events sent to Honeybadger Insights by using the honeybadger.BeforeEvent() function. This allows you to modify event data or skip events entirely before they are sent.

Modifying events

To modify or augment event data before it’s sent, add a callback that modifies the event map and returns nil:

honeybadger.BeforeEvent(
    func(event map[string]any) error {
        event["environment"] = "production"
        return nil
    }
)

Dropping events

To skip events from being sent, return honeybadger.ErrEventDropped:

honeybadger.BeforeEvent(
    func(event map[string]any) error {
        if event["event_type"] == "debug_event" {
            return honeybadger.ErrEventDropped
        }
        return nil
    }
)

Multiple callbacks

You can register multiple BeforeEvent callbacks. They will be executed in the order they were registered. If any callback returns ErrEventDropped, the event is skipped.

Example: Filtering sensitive data

A common use case is to filter sensitive data from events:

honeybadger.BeforeEvent(
    func(event map[string]any) error {
        // Remove sensitive fields
        delete(event, "password")
        delete(event, "credit_card")

        // Anonymize email addresses
        if email, ok := event["email"].(string); ok {
            event["email"] = anonymizeEmail(email)
        }

        return nil
    }
)

Example: Dropping high-volume events

You might want to drop certain high-volume events to reduce costs:

honeybadger.BeforeEvent(
    func(event map[string]any) error {
        // Drop health check events
        if event["event_type"] == "health_check" {
            return honeybadger.ErrEventDropped
        }

        // Drop events from internal services
        if source, ok := event["source"].(string); ok {
            if source == "internal-monitoring" {
                return honeybadger.ErrEventDropped
            }
        }

        return nil
    }
)