Prophetly

Prophetly is a privacy-first time series forecasting app. It runs Facebook Prophet directly in your browser using WebAssembly. Your CSV data stays on your machine, and no calculations rely on a remote backend server.

Features

• 100% Local & Private: All data parsing and model fitting happen inside background Web Workers using WebAssembly.
• Interactive Visualizations: View forecast predictions, uncertainty bounds, decomposed trends, seasonalities, and changepoints.
• Smart Cross-Validation: Evaluate model performance with rolling historical cutoffs, metrics (RMSE, MAE, MAPE, MDAPE, Coverage), and cancellation controls.
• Presets & Custom Settings: Choose starting presets or fine-tune growth models, prior scales, and interval widths.
• Local History & Exports: Store past runs locally in your browser and export results to CSV, JSON, or PNG chart images.

Getting started

Prerequisites

• Node.js (v22.0.0 or newer)
• npm (v10.0.0 or newer)

Development

1. Install dependencies:

   npm install

2. Start the local development server:

   npm run dev

3. Open http://localhost:5173 in your browser.

Available scripts

• npm run dev — Starts Vite dev server with HMR.
• npm run build — Compiles TypeScript and bundles production assets including WASM binaries.
• npm run preview — Serves the production build locally.
• npm run lint — Runs Biome code checks.