GitHub open-sources Replica for prototypes built with your design system
GitHub open-sourced Replica on October 28, giving product teams a way to prototype inside the Copilot app using their own design-system components and guidance. Designers supply the rules, while teammates describe and refine interactive ideas in natural language. The interesting distinction is not another blank-page generator. It is a reusable starting point shaped by the product a team already builds.
Local exploration and team publishing are different setups
The local walkthrough supports macOS and Linux. It requires the Copilot app with GitHub sign-in, Git, Node.js with npm, and local tooling including lsof. Match Node to the chosen starter’s package requirements rather than assuming one version works everywhere. A local prototype needs neither Hub nor Docker, a domain or a GitHub-hosted repository.
| Component | Purpose |
|---|---|
| Starter app | Reusable foundation for a prototype |
| Replica plugin | Canvas beside the Copilot conversation |
| Optional Replica Hub | Hosted prototypes and team comments |
| Build action | Publishing pipeline, not a local prerequisite |
The repository offers a Minimal starter and a CoreAI Sandbox with existing interface elements. GitHub-hosted models require a Copilot plan. Connecting your own provider is an alternative in public preview, with that provider’s costs and terms. Viewing a finished prototype or reviewing it in Hub does not require a Copilot subscription. Open-source tooling does not make model usage or hosting free.
Give the prototype real design guidance, not production data
The documented setup can install dependencies and the Replica plugin, and can install Copilot CLI if it is missing. Review repository setup before accepting it. The plugin and canvas have separate enablement switches, followed by a fresh session. A successful install message is not proof that the preview works.
Once the app runs, the guide uses /setup-skills to draft guidance from approved product documentation, component packages and design-system sources. Review that guidance before applying it. Use sample data and keep production credentials and real customer records out of the prototype.
An illustrative first task is an inventory filter with three synthetic products, an empty result and a reset control. Ask for existing approved components rather than visual lookalikes. Then test keyboard navigation, the empty state and reset behavior yourself. This is a suggested evaluation, not a Replica test ByteForward performed. A credible prototype should expose design decisions, not conceal them behind a polished screenshot.
Hub makes sharing possible, and adds operating work
The hosting guide calls for an organization-run Linux server with Docker, a dedicated domain, wildcard DNS and HTTPS, plus permission to create a private GitHub App. GitHub does not operate your Hub for you. Authors use the shared environment rather than deploying a server for each prototype.
The same guide separates a working local preview from a successful published build. It recommends testing an author’s publishing path and a reviewer’s comment path before inviting the team. Public sharing is off by default. A Hub address in repository configuration is not authorization to access it.
Self-hosting also does not mean every part of the workflow stays inside the organization. The README says Hub retains publishing and review activity for 90 days, while GitHub services and the chosen model provider have separate data terms. Optional analytics export requires configuration.
What the license does and does not settle
The code uses the MIT license, which permits reuse and modification with its notice requirements and without a warranty. The repository separately identifies bundled fonts under the SIL Open Font License. Those terms do not replace the permissions and terms attached to your own design assets, model provider or deployment.
Replica is distinct from the Copilot Projects and shared automations update. That organizes agent work and ownership. Replica supplies the prototype canvas and design-guidance workflow. Start by verifying one local interaction before taking on shared hosting. ByteForward reviewed the sources but did not install Replica or test its output.
