Nomulus is an open source, scalable, cloud-based service for operating
top-level domains (TLDs). It
is the authoritative source for the TLDs that it runs, meaning that it is
responsible for tracking domain name ownership and handling registrations,
renewals, availability checks, and WHOIS requests. End-user registrants (i.e.
people or companies that want to register a domain name) use an intermediate
domain name registrar acting on their behalf to interact with the registry.
Nomulus runs on Google App Engine and is written primarily in Java. It is
the software that Google Registry uses to
operate TLDs such as .google, .app, .how, .soy, and .みんな. It can run any
number of TLDs in a single shared registry system using horizontal scaling. Its
source code is publicly available in this repository under the Apache 2.0 free
and open source license.
The following resources provide information on getting the code and setting up a
If you are thinking about running a production registry service using our
platform, please drop by the user group and introduce yourself and your use
case. To report issues or make contributions, use GitHub issues and pull
Nomulus has the following capabilities:
- Extensible Provisioning Protocol
XML protocol that is the standard format for communication between
registrars and registries. It includes operations for registering, renewing,
checking, updating, and transferring domain names.
- DNS interface: The
registry provides a pluggable interface that can be implemented to handle
different DNS providers. It includes a sample implementation using Google
Cloud DNS as well as an RFC 2136 compliant implementation that works with
- WHOIS: A text-based protocol that
returns ownership and contact information on registered domain names.
- Registration Data Access Protocol
A JSON API that returns structured, machine-readable information about
domain name ownership. It is essentially a newer version of WHOIS.
- Registry Data Escrow (RDE): A daily
export of all ownership information for a TLD to a third party escrow
provider to allow take-over by another registry operator in the event of
serious failure. This is required by ICANN for all new
- Premium pricing: Communicates prices for premium domain names (i.e.
those that are highly desirable) and supports configurable premium
registration and renewal prices. An extensible interface allows fully
- Billing history: A full history of all billable events is recorded,
suitable for ingestion into an invoicing system.
- Registration periods: Qualified Launch Partner, Sunrise, Landrush,
Claims, and General Availability periods of the standard gTLD lifecycle are
- Brand protection for trademark holders (via
Allows rights-holders to protect their brands by blocking registration of
domains using their trademark. This is required by ICANN for all new gTLDs.
- Registrar support console: A self-service web console that registrars
can use to manage their accounts in the registry system.
- Reporting: Support for required external reporting (such as ICANN
CZDS, Billing and Registration Activity) as well
as internal reporting using BigQuery.
- Administrative tool: Performs the full range of administrative tasks
needed to manage a running registry system, including creating and
configuring new TLDs.
- DNS interface: An interface for DNS operations is provided so you can
write an implementation for your chosen provider, along with a sample
implementation that uses Google Cloud DNS.
If you are using Google Cloud DNS you may need to understand its
capabilities and provide your own
- GAE Proxy: App Engine Standard only serves HTTP/S traffic. A proxy to
forward traffic on EPP and WHOIS ports to App Engine via HTTPS is provided.
Instructions on setting up the proxy on
Google Kubernetes Engine
Running the proxy on GKE supports IPv4 and IPv6 access, per ICANN’s
requirements for gTLDs. The proxy can also run as a single jar file, or on
other Kubernetes providers, with modifications.
Registry operators interested in deploying Nomulus will likely require some
additional components that are need to be configured separately.
- A way to invoice registrars for domain name registrations and accept
payments. Nomulus records the information required to generate invoices in
- Fully automated reporting to meet ICANN’s requirements for gTLDs. Nomulus
includes substantial reporting functionality but some additional work will
be required by the operator in this area.
- A secure method for storing cryptographic keys. A keyring interface is
provided for plugging in your own implementation (see configuration
- System status and uptime monitoring.
- Donuts Registry has helped review the code and
provided valuable feedback
- CoCCa and FRED are other
open-source registry platforms in use by many TLDs
- We are not aware of any fully open source domain registrar projects, but
open source EPP Toolkits (not yet tested with Nomulus; may require
integration work) include:
- Some Open Source DNS Projects that may be useful, but which we have not