Cal.com
SchedulingThe open source scheduling infrastructure — a self-hostable Calendly alternative.
About this project
Cal.com is the open-source scheduling infrastructure that powers meeting booking for individuals, teams, and entire organizations. It's a fully self-hostable alternative to Calendly — with all the features you'd expect (booking pages, calendar sync, team routing, reminders, payments) plus an open API and white-label capability that proprietary tools simply cannot offer.
Market opportunity
Online scheduling software is a $500M+ market growing at 14% annually, anchored by Calendly which charges $8–$16/user/month and gates key features (team routing, round-robin, payments) behind its highest tiers. For agencies and enterprises running dozens of users, that's $10,000–$20,000+/year in scheduling software alone. Cal.com's self-hosted option eliminates that recurring cost entirely, while its API-first design makes it the right foundation for scheduling products.
Technical overview
- Stack: TypeScript end-to-end — Next.js frontend, tRPC API layer, Prisma + PostgreSQL, self-hostable with Docker.
- Calendar integrations: Google, Outlook, iCloud, Cal.com's own CalDAV server, Exchange.
- Features: booking pages, team scheduling, round-robin, collective events, workflows (reminders), payments (Stripe), and webhooks.
- API-first: a REST and webhook API lets you embed scheduling into any product — your users never need to leave your app.
- White-label: full custom branding and custom domain support.
Who's it for
Freelancers and consultants replacing Calendly, SaaS products embedding scheduling as a feature, enterprises wanting data control, and agencies building booking products for clients.
How to use it
Get started
Cloud (instant):
Create a free account at cal.com, connect your Google or Outlook calendar, and set your availability. Your booking page is live in under 5 minutes at cal.com/yourname.
Self-host:
git clone https://github.com/calcom/cal.com
cd cal.com
cp .env.example .env # set DATABASE_URL, NEXTAUTH_SECRET, and calendar credentials
npm install && npx prisma migrate deploy
npm run build && npm start
For quick Docker deployment:
docker compose up -d
Customize your booking page, set up team workflows, and embed the booking widget anywhere with the <cal-inline /> web component or the Cal.com JavaScript embed.
💡 How to make a business with it
How to make money with it
1. White-label scheduling SaaS for a niche. Host Cal.com with your own branding and sell it as a specialized scheduling product for one industry — medical practices, law firms, tutors, fitness coaches, real estate agents.
- Target: Professionals who find Calendly generic and overpriced
- Pricing: $15–$30/month per user
- Example: A "LegalBook" scheduling tool at $25/month × 400 attorneys = $120,000 ARR
- Difficulty: Medium — requires customization and a niche distribution strategy
2. Embedded scheduling inside your SaaS. Instead of linking users out to Calendly, embed Cal.com's scheduling directly inside your product using the JavaScript embed or API. Charge for it as a premium feature.
- Target: SaaS founders with a user base that needs booking (CRMs, project tools, coaching platforms)
- Pricing: $10–$20/month add-on per seat or a flat tier upgrade
- Example: 500 existing users upgrade at $15/month = $90,000 ARR from one week of integration work
- Difficulty: Simple if you already have a product
3. Setup and management for local service businesses. Restaurants, clinics, barbershops, and personal trainers all need booking systems. Set up Cal.com for them, configure their calendar rules and reminder workflows, and charge a retainer.
- Target: Local service businesses paying $30–$60/month for inferior booking tools
- Pricing: $300–$500 setup + $99/month managed service
- Example: 25 clients × $99/month = $29,700/year recurring on a single server
- Difficulty: Simple — no coding, mostly configuration and client onboarding
Need technical help?
Want help setting up Cal.com, customizing it, or building your product on top of it? Knock me — let's talk.