**JavaScript SDK:** [`swarmhit.managedDomains.create(params)`](/smart-api/sdk/methods#managedDomains) Use a domain the workspace already owns for bought mailboxes, instead of buying one: nothing is charged for the domain, only its mailboxes. Its DNS moves to Swarmhit: set the two `connection.nameservers` at the domain's registrar, replacing `connection.currentNameservers` (empty for a minute when our mail supplier is slow to answer: read the domain again). Its website records (A/AAAA at the root, `www`) are copied to its new DNS (`connection.websiteRecords`), so the site keeps working; nothing else is copied, so subdomains, other records and any email it has today stop working. The domain then connects on its own (`connection.state`: `nameservers` → `setting_up` → `ready`). Set the nameservers within about 12 hours: a pair not seen by then is replaced by a new one (`connection.nameserversChangedAt`, webhook `managed_domain.action_required` with `reason: nameservers_changed`). Follow it with GET /managed-domains/{id} or the `managed_domain.*` webhooks. Once `canAdd` is true, add mailboxes with a domain entry `{ name, existing: true, mailboxes }` in POST /mailbox-orders/quote. Nameservers not changed within 7 days: `expired`, add it again later. A domain another account had live here before needs support (`domain-taken`). Needs the managed mailboxes feature, billing rights (the key's creator) and a payment method on file. At most 5 domains connect at once, and 5 adds a minute.