Guides

Custom domain setup guides

Setting up a custom domain looks simple until you are staring at a registrar's DNS panel wondering whether the record type is CNAME or A, which of four nested menus holds it, and why the change has not propagated after twenty minutes. These guides document the records a setup actually needs, rather than walking through buttons that move the next time a provider redesigns its dashboard.

Start here

• How to set up a custom domain. The step-by-step version: which record to create, where it goes, and how to tell whether it worked.
• How to add custom domains to your SaaS. DNS, verification and TLS from the platform side, including the states a connection moves through.

By what you are building

• Let customers manage their own domains. Handing the domain step to the customer without handing them a support ticket.
• Manage client domains: the agency playbook. Running domains on behalf of clients, where the person configuring DNS is rarely the person who owns the registrar login.
• Automate TLS for customer domains. Issuing and renewing certificates for domains you do not own, and what happens when a renewal fails quietly.
• Let AI agents connect domains. The same verification steps a careful human takes, exposed so a process can call them.

Check a domain before you debug it

Before working through a guide, it is worth knowing which part is actually broken. The domain health check reads a domain's live DNS, HTTPS and certificate state and names the specific failure. It is free, and it does not ask for an account.

Terms these guides assume

Every guide here uses vocabulary that is obvious once you know it and opaque before then. The glossary defines the ideas the guides lean on, from apex domains and CNAME flattening to multi-tenant TLS.