Add a person or update them when you already know their email - set field values, tags, preferences, and subscription status in one call.

Matching is by email on your contact list. Returns 201 when created, 200 when updated. To change an existing contact's fields, tags, or preferences without sending a status, use Update contact details.

If the account has double opt-in enabled, requesting subscribed may leave the contact pending confirmation and send a confirmation email. New contacts cannot be added for blocklisted emails (422). For an existing blocklisted contact, the status you send is applied and removes it from your blocklist, the same as in the app. Restricted and suspended contacts cannot be updated (423). 423 if the account is locked for processing or has reached its contact limit.