One Calendar

A beautifully minimal open-source calendar app to plan your week and life

What is One Calendar?

One Calendar is a privacy-first, weekly-focused, open-source calendar app, designed to help individuals and teams plan, focus, and stay in sync.

Without One Calendar, your schedule is scattered. With it, your week feels intentional.

Why One Calendar?

Most calendar tools are cluttered, over-engineered, or locked behind paywalls. One Calendar aims to be:

• 🧠 AI Powered – AI-first app that streamlines your scheduling.
• 🕹 Interactive & Smooth – Drag, drop, right-click, and edit with ease.
• 🔐 Private & Local – Your data is yours. E2EE. Share, backup, and control.
• ☁️ Cloud Sync – Optional sync via PostgreSQL.
• 🌐 Clerk Account – Easily login with third-party.
• 🌍 International – Automatically adapts to your language (English / 中文).
• 🧱 Customizable – Tailor themes, default view, and integrations.

Tech Stack

• Frontend: Next.js 16, Tailwind CSS, Shadcn UI, TypeScript
• Auth: Clerk
• Storage: PostgreSQL
• Weather: OpenWeather API
• AI: Groq API
• Deploy: Vercel

Preview

Getting Started

Prerequisites

Required Versions:

• NodeJS (v20 or higher)
• Bun (v1.2 or higher)

Quick Start

# Clone the repo
git clone https://github.com/EvanTechDev/One-Calendar.git
cd One-Calendar

# Install dependencies
bun install

# Start the app
bun dev

Then visit http://localhost:3000

Environment Variables

Copy .env.example to .env and fill in:

# Required 
NEXT_PUBLIC_BASE_URL=http://localhost:3000

# Auth (Required)
NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY=your-clerk-publishable-key
CLERK_SECRET_KEY=your-clerk-secret

# Optional
GROQ_API_KEY=your-groq-api
OPENWEATHER_API_KEY=your-open-weather-api-key

# Optional, database
POSTGRES_URL=postgres://postgres:postgres@localhost:5432/onecalendar

# Optional, Cloudflare turnstile captcha
NEXT_PUBLIC_TURNSTILE_SITE_KEY=site-key
TURNSTILE_SECRET_KEY=secret-key

Environment Setup

1. PostgreSQL

Run this command if you installed docker

bun run db

And the env:

POSTGRES_URL=postgres://postgres:postgres@localhost:5432/onecalendar

Star History

The Team

Brought to you by a small team of makers who love clean tools and open-source.

Check out our contributors ❤️

Sponsor

BTC: bc1qdhn6c7tlcaflzu3u5fva825l20k9eqnqag5xzj

Acknowledgements

This project wouldn't be possible without these awesome services:

License

This project is licensed under the GNU General Public License v3.0 (GPL-3.0).
See the LICENSE file for details.