Update a sequence

Updates any sequence settings — name, email_address, schedule (send_days, send_hour, time_zone), email_template_id, exclude_subscriber_sources, or the active / repeat / hold flags. Only fields included in the request body change; everything else is preserved.

Some changes have user-visible side effects on subscribers already in the sequence:

Note: flipping active from false to true resumes delivery for queued subscribers. Flipping it back to false pauses the sequence — subscribers stay in their current position but no new emails are sent until it's reactivated.

Note: changing the schedule (send_days, send_hour, or time_zone) only affects future sends. It does not retroactively reschedule emails already queued for delivery.

Warning: turning off repeat while subscribers are mid-sequence does not stop them from finishing — but they won't be re-eligible to start over after completing.

See Create a sequence for the full sequence model and what each field controls.