Zero Calendar

Zero Calendar

AI-powered scheduling with natural language event creation, Google Calendar sync, invite emails, and analytics built on Next.js, Convex, and Better Auth.

[](https://vercel.com/new/clone?repository-url=https://github.com/x1xhlol/zero-calendar&project-name=zero-calendar&repository-name=zero-calendar)

Features

• Natural-language scheduling and calendar actions
• Google Calendar sync and webhook-based updates
• Invite flows with email delivery through Resend
• Calendar analytics, conflict detection, and free-time discovery
• Better Auth + Convex-backed authentication and user data
• Modern Next.js App Router UI

Stack

• Next.js 16
• React 19
• Bun
• Convex
• Better Auth
• OpenRouter AI SDK
• Resend

Quick start

1. Install dependencies

bun install

2. Create your environment file

Create `.env.local` and set the values your deployment needs:

BETTER_AUTH_SECRET=
SITE_URL=http://localhost:3000
NEXT_PUBLIC_SITE_URL=http://localhost:3000

NEXT_PUBLIC_CONVEX_URL=
CONVEX_URL=
CONVEX_SITE_URL=
NEXT_PUBLIC_CONVEX_SITE_URL=

GOOGLE_CLIENT_ID=
GOOGLE_CLIENT_SECRET=

OPENROUTER_API_KEY=
OPENROUTER_MODEL=x-ai/grok-4.1-fast

RESEND_API_KEY=
RESEND_FROM_EMAIL="Zero Calendar "

3. Start Convex

If you need to regenerate Convex types or run the backend locally:

bunx convex dev

4. Start the app

bun dev

Open http://localhost:3000.

Environment variables

Variable	Required	Purpose
BETTER_AUTH_SECRET	Yes	Shared secret used by Better Auth and server-side Convex access control. Set the same strong random value in both your Next.js and Convex environments.
SITE_URL	Yes	Canonical server-side site URL used by auth flows.
NEXT_PUBLIC_SITE_URL	Yes	Public site URL used by the client and invitation links.
NEXT_PUBLIC_CONVEX_URL	Yes	Public Convex deployment URL for the f