What is Replica?
Replica is an open-source prototyping tool from GitHub Design and Microsoft CoreAI Design, announced on 28 October 2026. Designers write the guidance once, in a prototype repository holding the team's components, patterns and documentation; anyone on the product team then describes what they want in the GitHub Copilot app, and the Replica canvas shows the running prototype beside the conversation, clickable and ready to refine.
It has four parts: starter apps (a minimal one to adapt to your design system, and a CoreAI Sandbox built on Microsoft's CoreAI design system), the Replica plugin for the Copilot app, a GitHub build action, and an optional Replica Hub that your organisation hosts so teammates can open published prototypes and leave comments. Local prototyping needs the Copilot app, Git and Node.js on macOS or Linux; Hub also needs a Linux server and a dedicated domain with wildcard DNS and HTTPS.
It runs on GitHub-hosted models through a Copilot plan, or on your own model provider without one, an option still in public preview. The code is MIT, maintained by GitHub staff, and Hub reached v1.0.1 on 10 November 2026.
Is Replica worth it?
Replica's argument is that generic AI prototypes look like nobody's product. Instead of a model inventing buttons and spacing, Replica points it at a repository where designers have already written down the team's components, patterns and rules, so a product manager's prompt in the Copilot app produces a screen in the house style. The prototype runs beside the chat and can be clicked through and changed by conversation.
That makes its value proportional to the work already done. A team with a maintained design system and documentation gets prototypes that match the product; a team without one gets the minimal starter and, as H2S Media put it, a solution to a problem it does not have yet. The CoreAI Sandbox starter shows the intended end state using Microsoft's own design system.
The setup is heavier than Figma Make or v0. The documented workflow needs the GitHub Copilot app and a GitHub sign-in, on macOS or Linux; Windows is not supported. Sharing needs Replica Hub on your own Linux server with a dedicated domain, wildcard DNS and HTTPS. Model use is either a Copilot plan, from $10 a month for Pro, or your own provider, which is in public preview.
The data story is straightforward. Hub is self-hosted, keeps publishing and review activity in its own database for 90 days, and exports to Segment, Mixpanel or a webhook only if an administrator sets it up; nothing goes to GitHub automatically. The README is careful to add that prompts still go to GitHub's services or your chosen model provider under their terms.
It is young: the repository was created on 15 October 2026, has about 260 stars, 12 contributors and 18 open issues and pull requests, and prototypes are not production code. Against Open Design, which works with any coding agent and keeps a design system in one DESIGN.md file, Replica is tied to Copilot but far better at holding a large organisation's existing components.
Where it earns its place
A product manager at a 300-person SaaS company with a mature component library
Show engineering a new settings flow before writing a spec
Describe the flow in the Copilot app on a Copilot Business seat ($19/user/month) and click through the prototype built from the team's own components; publish it to Hub for comments.
A design-systems lead at a large enterprise
Make AI prototypes follow approved patterns instead of inventing new ones
Write the guidance and component docs into the prototype repository once, then let any team start from it; the effort moves from fixing off-brand mock-ups to maintaining the guidance.
A platform engineer asked to host Replica Hub
Stand up internal sharing with acceptable data handling
Provision a Linux server, a dedicated domain with wildcard DNS and HTTPS, and GitHub permissions; Hub keeps activity 90 days in its own database and exports nothing unless configured.
Before you commit
- Setup
- Install the GitHub Copilot app, Git and Node.js on macOS or Linux, run copilot plugin install replica-prototype@replica, and start from the minimal or CoreAI Sandbox starter; no Hub is needed to try it locally.
- Integrations
- GitHub Copilot app and GitHub-hosted models, your own model provider (public preview), a GitHub build action for publishing, and Hub analytics export to Segment, Mixpanel or a custom HTTPS endpoint.
- Data and privacy
- Hub is operated by your organisation and keeps publishing and review events for 90 days, sent to GitHub only if you configure it; prompts go to GitHub's services or your model provider under their terms. MIT.
- Cost at scale
- Software is free; seats are Copilot plans for builders only, such as Business at $19/user/month, since viewers and reviewers need none, plus one Linux server for Hub.
- Limits
- macOS and Linux only; prototypes are not production-ready and need separate accessibility and interaction checks; 18 open issues and pull requests on a four-week-old repository.
What’s good
- Prototypes use your own components, patterns and documentation
- Runs in the Copilot app with the prototype beside the chat
- Self-hosted Hub for comments; activity kept 90 days and not sent to GitHub
- MIT licence, maintained by GitHub staff
What’s not
- Needs the GitHub Copilot app and a GitHub sign-in
- No Windows support; Hub needs a Linux server and wildcard domain
- Little benefit without an existing design system
- Bring-your-own-model option still in public preview
Best for
Product teams with a documented design system and GitHub Copilot who want designers, PMs and engineers prototyping in the same visual language.
Replica alternatives
Replica: common questions
- Is Replica worth it?
- The right idea for teams with a real design system, since prototypes come out looking like your product, but it asks for the Copilot app, a Mac or Linux machine and a server before it pays off. We rate it 3.6 out of 5.
- How much does Replica cost?
- Free and open source (MIT). Building prototypes needs a GitHub Copilot plan (from $10/month for Pro) or your own model provider's API costs; viewing and commenting need no Copilot subscription. Hub runs on your own server.
- What are the downsides of Replica?
- Needs the GitHub Copilot app and a GitHub sign-in; no Windows support; Hub needs a Linux server and wildcard domain; little benefit without an existing design system; bring-your-own-model option still in public preview.
- Who is Replica best for?
- Product teams with a documented design system and GitHub Copilot who want designers, PMs and engineers prototyping in the same visual language.
- How much does Replica cost for a team or in production?
- Software is free; seats are Copilot plans for builders only, such as Business at $19/user/month, since viewers and reviewers need none, plus one Linux server for Hub.
- Is Replica safe for company data?
- Hub is operated by your organisation and keeps publishing and review events for 90 days, sent to GitHub only if you configure it; prompts go to GitHub's services or your model provider under their terms. MIT.
- What are the best Replica alternatives?
- The closest alternatives we have reviewed are OpenDesign.
Answers checked Nov 11, 2026.