Cal.com: Open-Source Self-Hosted Scheduling Platform

What Is Cal.com?

Cal.com is an open-source scheduling platform — think Calendly, but you own the code, the data, and the deployment. 32K+ GitHub stars.

Why It Matters

• No vendor lock-in — switch hosting anytime
• Full API access — embed scheduling in your product
• Custom workflows — trigger webhooks, emails, SMS on booking
• White-label — remove branding, use your domain
• GDPR compliant — data stays on your infrastructure

Key Features

Architecture

┌──────────────────────────────────────┐
│           Cal.com Stack              │
│                                      │
│  ┌──────────────┐  ┌─────────────┐  │
│  │   Next.js    │  │   Prisma    │  │
│  │   Frontend   │  │   ORM       │  │
│  └──────┬───────┘  └──────┬──────┘  │
│         │                  │         │
│         └────────┬─────────┘         │
│                  │                   │
│          ┌───────▼───────┐           │
│          │  PostgreSQL   │           │
│          └───────────────┘           │
│                                      │
│  Integrations: Google Calendar,      │
│  Outlook, Zoom, Meet, Stripe         │
└──────────────────────────────────────┘

Self-Host on Kubernetes

Helm Deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  name: calcom
  namespace: scheduling
spec:
  replicas: 2
  template:
    spec:
      containers:
        - name: calcom
          image: calcom/cal.com:latest
          ports:
            - containerPort: 3000
          env:
            - name: DATABASE_URL
              valueFrom:
                secretKeyRef:
                  name: calcom-secrets
                  key: database-url
            - name: NEXTAUTH_SECRET
              valueFrom:
                secretKeyRef:
                  name: calcom-secrets
                  key: nextauth-secret
            - name: NEXTAUTH_URL
              value: "https://cal.yourdomain.com"
            - name: CALENDSO_ENCRYPTION_KEY
              valueFrom:
                secretKeyRef:
                  name: calcom-secrets
                  key: encryption-key
          resources:
            requests:
              memory: "512Mi"
              cpu: "250m"
            limits:
              memory: "1Gi"
              cpu: "1"

Docker Compose (Quick Start)

version: "3.9"
services:
  calcom:
    image: calcom/cal.com:latest
    ports:
      - "3000:3000"
    environment:
      - DATABASE_URL=postgresql://cal:cal@db:5432/calcom
      - NEXTAUTH_SECRET=your-secret-here
      - NEXTAUTH_URL=http://localhost:3000
    depends_on:
      - db
  db:
    image: postgres:16-alpine
    environment:
      - POSTGRES_USER=cal
      - POSTGRES_PASSWORD=cal
      - POSTGRES_DB=calcom
    volumes:
      - pgdata:/var/lib/postgresql/data

volumes:
  pgdata:

Workflow Automations

Cal.com triggers webhooks on every booking event:

// Webhook payload on BOOKING_CREATED
{
  "triggerEvent": "BOOKING_CREATED",
  "payload": {
    "title": "AI Strategy Consultation",
    "startTime": "2026-06-10T10:00:00Z",
    "endTime": "2026-06-10T10:30:00Z",
    "attendees": [{"name": "Client", "email": "client@company.com"}],
    "organizer": {"name": "Luca Berton", "email": "luca@lucaberton.com"}
  }
}

Connect to n8n or Zapier for:

• CRM record creation (HubSpot, Salesforce)
• Slack notification to your team
• Pre-meeting email with agenda template
• Invoice generation after meeting

When to Use Cal.com

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