action'email' | 'webhook' | 'slack' | 'discord' | 'http_get' | 'materialize' | 'telegram' | 'enrich_snapshot' | 'query_snapshot' | 'sheets_append'
trigger_type'cron' | 'event'
schedulestring
Cron expression (cron jobs only).
event_type'artifact.updated' | 'artifact.viewed' | 'comment.added' | 'email.received'