How Fabricator works

Fabricator wraps the tools you would otherwise run by hand. You describe the app, the built-in GitHub Copilot agent edits a local Rayfin project, Fabricator previews the result, and Rayfin deploys it to Microsoft Fabric.

The loop

1. You create, open, or clone a Rayfin project.
2. You type a request in chat.
3. The bundled Copilot engine reads and edits files in the project folder.
4. Fabricator records changes with git so you can inspect diffs and history.
5. Fabricator starts the project's local Vite frontend during chat turns when the project has Vite installed.
6. Fabricator runs the project-pinned Rayfin CLI for deploys.
7. The preview shows the deployed app, the Fabric portal shell, or the local frontend while Copilot is working.
8. The Advisor runs quick checks locally and can start a read-only Copilot review.

Main pieces

Architecture diagram

What runs on your computer

Fabricator stores settings, project lists, chat history, Advisor state, logs, and diagnostics exports under the app data folder. Your Rayfin apps live in the workspace folder, which defaults to RayfinProjects in your home directory. See Files and folders.

The desktop app uses Tauri v2: a Rust core with a React renderer. On Windows, the embedded preview uses WebView2. On macOS, it uses the system web view.

Accounts

Fabricator doesn't keep credentials itself; each tool keeps its own.

• GitHub Copilot: the bundled Copilot engine stores the sign-in.
• Microsoft Fabric: the Rayfin CLI keeps one signed-in account per config folder, ~/.rayfin by default. Fabricator gives each Fabric account added after the first its own folder under the app data folder, and points every Rayfin CLI and helper process it starts at the account in use with RAYFIN_CONFIG_DIR. Sign-in, sign-out and sign-in checks run the project's pinned Rayfin CLI outside the project folder, because the CLI reads the project's rayfin.yml at startup. The project's Fabric environment overrides in rayfin/.env still apply.
• Azure CLI: the Azure CLI keeps every account you sign in to. Fabricator lists them with az account list, switches with az account set, signs one out with az logout --username, and signs in with az login --allow-no-subscriptions, so accounts without an Azure subscription work.
• GitHub: the GitHub CLI keeps every account you sign in to. Add account runs gh auth login in a terminal and then switches back to your default account.

When you open Fabricator after setup has passed, it shows your work at once and checks tools and accounts in the background. Each check runs separately, so a slow one, such as Fabric's, doesn't delay the others.

What goes over the network

Fabricator and the tools it runs can contact these services:

• GitHub Copilot for chat, model access, design options, deep Advisor reviews, and team workspace diagnoses.
• Microsoft Fabric and Rayfin services when you sign in, deploy, preview deployed apps, share apps, or inspect Fabric items.
• GitHub for update checks, release downloads, cloning repositories, issue reporting, and team workspace repositories.
• The npm registry when creating a project from the Rayfin CLI's template or installing project dependencies.
• Azure and GitHub APIs for team workspace setup and Diagnose with Copilot when the Team workspaces experiment is enabled.

What the Advisor can read

Quick checks run locally against the project snapshot. Run deep review starts a read-only Copilot review. That review can read your project and rayfin.ai documentation, but it is not allowed to edit files, run commands, or open .env files.