Zephyr

Yes. Your servers, your PostgreSQL, your customer data — none of which leaves your machines. The only thing that talks to us is the update check, which asks what the current release is and presents your licence.

No. kstack is the path with no integration work, but cPanel, Plesk, DirectAdmin, Enhance, Proxmox, Hetzner Cloud and OpenStack are all supported — written against the same plugin interface, which is public.

Yes — clients, hosting accounts, domains and invoices, read straight from the source database. The import is **dry-run by default** and **idempotent**, so you can rehearse it until the numbers match before cutting over. Original invoice numbers are preserved. Passwords are the one thing that cannot come across: they are hashed at the source with a scheme that cannot be reversed, so customers set a new one on first sign-in. Tell them before the cutover, not after.

The software keeps running and your customers keep being served. You stop receiving updates, and the admin tells you so plainly rather than degrading quietly.

Yes — scoped keys, per-key rate limiting, an OpenAPI document, and HMAC-signed outgoing webhooks with retry. There is also a governed MCP endpoint, if you would rather ask for work in words from your own AI client.

As integer minor units with an ISO 4217 currency, everywhere — `1299` is £12.99. Nothing in the platform stores money as a float, over a double-entry ledger rather than a balance column.

Node 26 and PostgreSQL 18, with Redis for queues, on a plain VPS or dedicated machine. One installer script handles Alpine with OpenRC or Ubuntu/Debian with systemd. **There is no Docker in production.**