Registrar APIs vs DNS Interfaces: Tenant Migration

In a tenant migration, a registrar API changes where your domain is registered and how the domain itself is managed (renewals, transfers, WHOIS), while a DNS interface changes only the records that tell the internet where your services live. This distinction matters because migrating a tenant usually involves moving both the registration and the DNS hosting, and confusing the two can cause downtime or lost domain control.

Background: Why the distinction exists

Every domain name has two separate layers of management. The registrar is the company that holds the domain’s registration with the central registry (like Verisign for .com). The registrar handles the domain’s lifecycle: renewal, transfer, contact information, and the delegation of nameservers. The DNS (Domain Name System) is the distributed directory that translates your domain into IP addresses. DNS hosting can be provided by the registrar, but it is often provided by a separate service like Cloudflare, Route 53, or a dedicated DNS provider.

When you migrate a tenant (a customer, a client, or an internal project) from one infrastructure to another, you typically need to move both layers. The registrar API is the programmatic interface to the registrar’s functions; the DNS interface is the programmatic interface to the DNS records. They are separate because they solve different problems: the registrar API manages the domain’s existence, while the DNS interface manages the domain’s resolution.

How registrar APIs work

A registrar API allows you to automate actions that you would normally do through the registrar’s web dashboard. Common operations include:

• Checking domain availability
• Registering or renewing a domain
• Transferring a domain from another registrar (initiating and accepting transfers)
• Updating WHOIS contact information
• Setting or changing the domain’s nameservers
• Enabling or disabling privacy protection

Most registrars offer RESTful APIs with authentication via API keys or OAuth. The API communicates with the registrar’s backend, which then communicates with the registry. For example, when you change nameservers via the registrar API, the registrar sends an EPP (Extensible Provisioning Protocol) command to the registry to update the domain’s delegation records.

During a tenant migration, the registrar API is what you use to transfer the domain itself from the old registrar to the new one. This is a formal process that requires an authorization code (EPP code) from the losing registrar and approval from the domain’s administrative contact. The API can automate this, but it cannot bypass the registry’s transfer rules, which typically include a 60-day lock after registration or transfer.

How DNS interfaces work

A DNS interface is the API or control panel provided by your DNS hosting service. It lets you manage DNS records such as A, AAAA, CNAME, MX, TXT, and NS records. Operations include:

• Creating, updating, and deleting records
• Managing zones (a zone is a container for all records for a domain)
• Setting TTL (time-to-live) values
• Enabling DNSSEC
• Viewing query logs

DNS interfaces are typically simpler than registrar APIs because they only affect how the domain resolves, not the domain’s registration. When you migrate a tenant, you use the DNS interface to recreate the tenant’s DNS records in the new DNS provider, or to update the records if the tenant’s IP addresses change.

A common misconception is that changing nameservers (which you do via the registrar API) is the same as changing DNS records. It is not. Nameservers tell the global DNS system where to find the authoritative DNS zone for your domain. The DNS zone contains the actual records. If you change nameservers without recreating the zone at the new provider, the domain will stop resolving.

What each changes in a tenant migration

In a tenant migration, the registrar API and DNS interface change different things:

• Registrar API changes: The domain’s registration details, including the registrar of record, WHOIS contacts, and the nameservers that the domain points to. These changes affect the domain’s existence and ownership.
• DNS interface changes: The actual DNS records that map the domain to IP addresses and services. These changes affect where traffic goes.

For example, if you are moving a tenant’s website from one cloud provider to another, you might:

1. Use the DNS interface to create a new zone at the new DNS provider with the same records (or updated IPs).
2. Use the registrar API to change the nameservers to point to the new DNS provider.
3. Use the registrar API to transfer the domain to a new registrar if the tenant wants to consolidate billing.

The key is that step 2 (nameserver change) is a registrar API function, not a DNS interface function. If you only use the DNS interface to update records at the old DNS provider, the domain still resolves there, but you have not moved the DNS hosting. If you only use the registrar API to change nameservers, you must ensure the new DNS provider has the correct zone, or the domain will break.

Common problems and how to avoid them

Several issues commonly arise during tenant migrations when the registrar API and DNS interface are confused:

• Downtime due to missing zone: Changing nameservers before the new DNS provider has a zone for the domain causes a SERVFAIL or NXDOMAIN. Always create the zone and verify records before switching nameservers.
• Transfer lock: Domains are often locked for 60 days after registration or transfer. Attempting to transfer a domain via the registrar API during this period will fail. Plan the migration around these locks.
• TTL and caching: When you change records, old values may be cached by resolvers for up to the old TTL. Lower the TTL before the migration to speed up propagation, then raise it back afterward.
• DNSSEC: If DNSSEC is enabled, changing nameservers or DNS providers requires updating the DS records at the registrar. Forgetting this breaks validation.
• API rate limits: Both registrar APIs and DNS interfaces have rate limits. Bulk operations (e.g., updating hundreds of records) may hit these limits. Batch requests and add delays.

To avoid these, create a detailed migration plan that separates registrar changes from DNS changes. Test the DNS zone at the new provider before switching nameservers, and use a low TTL (e.g., 300 seconds) during the transition.

How to choose the right approach

Choosing whether to use the registrar API, the DNS interface, or both depends on your migration goals:

• If you are only moving web hosting or servers: You only need to update DNS records (A, AAAA, CNAME) via the DNS interface. You do not need to touch the registrar.
• If you are changing DNS providers: You need to use the DNS interface to recreate the zone at the new provider, and the registrar API to change nameservers.
• If you are changing registrars: You need the registrar API to initiate and complete the transfer. This also usually involves updating nameservers at the new registrar.
• If you are consolidating tenants: You may need to do both, but often the DNS records are the same; only the registrar changes.

Consider the tenant’s needs: Do they want to keep the same DNS provider? Do they need to move to a new registrar for billing reasons? Answering these questions determines which interface you use.

Costs and safety considerations

Registrar transfers often involve fees (the new registrar typically charges a year’s registration fee, which extends the domain’s expiration by a year). DNS hosting is often free, but premium DNS features (like health checks or advanced routing) may cost extra. There are no standard prices; they vary by provider.

Safety is critical:

• Always back up your DNS zone before making changes. Most DNS interfaces allow exporting the zone file.
• Use API credentials with the least privilege necessary. Do not use a global admin key for a simple DNS update.
• Enable two-factor authentication on both registrar and DNS accounts.
• Test the migration in a staging environment if possible, using a subdomain or a test domain.

If the tenant is a business, consider the risk of downtime. Even a few minutes of DNS misconfiguration can result in lost revenue. Plan a rollback strategy: keep the old DNS zone active until the new one is verified.

Alternatives and comparisons

If you do not want to use APIs, you can manually perform the same actions through the web dashboards. Manual methods are fine for a single domain, but they are error-prone for bulk migrations. Some DNS providers offer migration tools that import zones from another provider via AXFR or zone file upload. These tools still require you to update nameservers via the registrar.

Another alternative is to use a DNS management service that acts as a proxy, allowing you to keep the same DNS provider while changing the registrar. In that case, you only use the registrar API to transfer the domain, and the DNS interface remains unchanged. This is a common pattern when a tenant wants to switch registrars but keep their DNS setup.

Comparing the two interfaces:

• Registrar API is for domain lifecycle management; it is slow (transfers take days) and has strict rules.
• DNS interface is for record management; it is fast (propagation takes minutes to hours) and flexible.

Both are essential for a complete migration, but they operate on different timescales and have different failure modes.

Frequently Asked Questions

Can I change DNS records using the registrar API?

No, not typically. The registrar API manages the domain registration and nameservers, but the DNS records are managed by the DNS hosting service. Some registrars also offer DNS hosting, and their API may include DNS endpoints, but that is a separate feature from the registrar functions.

What happens if I change nameservers without recreating the DNS zone?

The domain will stop resolving because the new nameservers will not have any records for the domain. Visitors will see a DNS error. Always recreate the zone at the new DNS provider before switching nameservers.

How long does a domain transfer take?

Transfers typically take 5 to 7 days, but they can be faster if the losing registrar approves quickly. The process involves the gaining registrar sending a transfer request to the registry, which then notifies the losing registrar. The losing registrar has 5 days to approve or deny.

Do I need to transfer the domain if I only change hosting providers?

No. If you are only changing the server that hosts the website, you only need to update the A record (or CNAME) in the DNS interface. The domain can stay with the same registrar.

What is the difference between a nameserver change and a DNS record change?

A nameserver change tells the global DNS system which servers hold the authoritative zone for your domain. A DNS record change updates the actual records (like IP addresses) within that zone. Nameserver changes are done via the registrar API; record changes are done via the DNS interface.

Can I use the same API for both registrar and DNS functions?

Some providers offer a unified API that includes both registrar and DNS endpoints, but they are still distinct functions. For example, a provider like Cloudflare offers both, but the endpoints are separate. You can use a single API client, but the operations are different.

Related

• Should You Buy AI Prompts? What to Know First
• Essential Work From Home Gadgets for a Better Setup
• AT&T Cheap Internet: Plans, Eligibility and What to Expect