Data Model

Nucleus represents assets in a hierarchical, tree-like structure. To an end user it looks just like a familiar file tree, with directories and files within.

Files can be uploaded, downloaded, and moved; directories created, deleted, moved, and listed.

Nucleus utilizes a single file tree similar to Unix systems, with a “path” to a file being a forward-slash (/) separated string of “nodes”:

  • /Users/jdoe/

  • /Users/jdoe/myfile.usd

While any file types can be uploaded to Nucleus (users can upload anything to Nucleus as if it was a traditional file server), the most common data formats used across Omniverse are .USD (Universal Scene Description), .MDL (Material Definition Library), various kinds of images (.jpg, .png), and similar.


Nucleus is a collection of services that avail themselves on a network and allow Client applications to connect to those services. Note that Clients can be desktop, user manipulated, applications (i.e., CAD or content creation software), as well as microservices - automated processes (rendering, content manipulation and generation), or whatever you may desire.


Within Nucleus, there are a number of components, each one communicating with multiple others. The most important of those communications are shown on the diagram, and some lines are omitted for clarity. One example of such an omission would be the Tagging Service using Authentication Service to generate a ticket for later communication with Nucleus Core.

Externally, some of those services expose API endpoints (open ports) for Clients to talk to them directly. Those ports and endpoints would depend on your distribution.

One notable feature is Caching - Clients can (and should) be configured to utilize at least one Cache to optimize downloads of heavy assets. Comprehensive information on Nucleus Cache can be found here.


Nucleus Core

At the center of Nucleus is its Core - a set of services for storing and retrieving data (files).

Nucleus Core is exposed to other parts of Omniverse via its API, over HTTP and Websockets connections.

On the backend, it utilizes a data directory configured by an administrator to store its data. This directory is opaque to the user, and does not represent the actual file tree in Nucleus.

Nucleus Core consists of the following components:

  • Nucleus Core API Responder: the primary component exposing Nucleus Core API

  • Nucleus Core LFT (Large File Transfer) Service: in Enterprise deployments, exposes an HTTP endpoint for upload and download of files of larger sizes. (The LFT Service can be scaled to run more than one instance.)

  • In Enterprise Nucleus Server installations, Core includes extras for exposing metrics, processing and rotating logs, etc.


The Discovery service rides “alongside” Nucleus and enables other services to register and advertise themselves to Clients.

Auth and User Management Service

This service and its configuration and operation is explained in greater detail. Click here to learn more.

Nucleus Navigator

Nucleus Navigator makes it easy to browse the data stored in Nucleus using a web browser, from Nucleus tab within the Omniverse Launcher, or by using the standalone Nucleus Navigator application.

Click here to learn more about Nucleus Navigator.

Utility Services

Other services included in Nucleus are:

  • Search Service: indexes items in Nucleus, and provides API for searching them

  • Thumbnail Service: creates thumbnails for data formats it supports

  • Tagging Service: exposes API to allow users to tag files in Nucleus file tree

Client Assumptions and Expectations

All Omniverse components that connect to Nucleus make the following assumptions:

  • Nucleus Core API is available on port 3009

  • Nucleus Discovery is available on port 3333

If an Enterprise Nucleus Server is deployed with an SSL/TLS gateway (ingress router) in front, Clients will make the following assumptions when told to connect to host (where host is the DNS hostname of the Nucleus Server):

  • If a port is specified when connecting, connections will be made via HTTPS and WSS on that host and port

  • If no port is specified, an HTTP connection to port 80 and HTTPS connection to port 443 will be attempted. The former is necessary for supporting redirects.


If transport security is desired, an Enterprise Nucleus Server allows SSL/TLS to be implemented as a standard gateway we call Ingress - a basic HTTPS termination endpoint - that acts as a reverse proxy. Clients talk SSL/TLS to the Ingress Gateway, and the Ingress Gateway uses standard HTTP/Websockets to talk to Nucleus Services.

For additional information about SSL/TLS configuration, click here.

Nucleus Distributions

Omniverse Nucleus is the database and collaboration engine of Omniverse. With Nucleus, teams can have multiple users connected together live with multiple applications all at once. This fosters users to use the application(s) they are the most comfortable and quickest with and allows for rapid iteration.

Nucleus offers a set of fundamental services that allow a variety of client applications, renderers, and microservices all to share and modify representations of virtual worlds together.

Nucleus operates under a publish/subscribe model. Subject to access controls, Omniverse clients can publish modifications to digital assets and virtual worlds to the Nucleus database or subscribe to their changes.

Nucleus can be installed in multiple ways to suit your needs: on an individual workstation, on-premises using an Enterprise Nucleus Server, or in your preferred Cloud Service Provider.

Nucleus Workstation


Nucleus Workstation provides a comprehensive set of services to evaluate Nucleus. It is intended for those who want to try Omniverse locally and collaborate with a small number of users.

Nucleus Workstation supports both Linux and Windows and supports all essential features of Nucleus, and can be connected to by Omniverse Client applications.

Enterprise Nucleus Server


Enterprise Nucleus Server is intended for Enterprise deployments in both on-premises or in your preferred Cloud Service Provider. It includes and supports all services and features available including:

  • Caching- Omniverse Cache speeds up your users by keeping the data close to them and avoiding the need to download files.

  • Enterprise backup and restore functionality- Sample scripts are provided as part of the Enterprise Nucleus Server for you to craft your own custom backup tooling to suit your requirements.

  • Advanced authentication and security features- Including Single Sign On (SSO) and SSL/TLS.

Currently, Enterprise Nucleus Server is provided as Docker Compose artifacts, however Kubernetes artifacts are planned for the future.