Sync Calendars Once. Everywhere.
Connect Google, Microsoft 365, and more through one unified API. For developers building apps. For users keeping calendars in sync.
Why Use Calendar Sync?
Built for developers and users who need calendars to work together seamlessly.
Unified API
One integration instead of separate Google & Microsoft APIs. Build once, support everywhere.
Two-Way Sync
Changes sync seamlessly across all your calendars in real-time. Never miss an update.
Enterprise Security
OAuth tokens encrypted at rest. Your credentials are never exposed. You maintain control.
Easy to Integrate
Simple REST API with clear documentation, code samples, and webhooks ready to go.
Built for Developers
Everything you need to integrate calendar sync into your application.
RESTful API
Clear, documented endpoints for connections, events, free/busy queries.
OAuth Handled
We manage all OAuth flows, token refresh, and expiration — no credential exposure.
Webhook Support
Real-time push notifications for instant sync — don't wait for polling intervals.
Get Started in Minutes
curl -X POST https://api.calendarsync.io/connections \
-H "X-Api-Key: cs_live_..." \
-H "Content-Type: application/json" \
-d '{
"owner_id": "user_123",
"provider": "google"
}'
# Response:
{
"data": {
"connection_id": 1,
"authorize_url": "https://accounts.google.com/o/oauth2/..."
}
}Designed for Everyone
Whether you're managing your personal schedule or coordinating across multiple calendars, Calendar Sync makes it simple and secure.
Connect Once
Link your Google or Microsoft calendar once and access it everywhere
Always In Sync
Never miss an appointment or double-book again. Real-time updates across all devices
Privacy First
Your calendar data is encrypted and secure. We don't store your credentials
Who Can Use It
Calendar Sync works for a wide range of users and organizations. Here are some personas who benefit most from our platform.
Booking & Scheduling Platforms
Sync client calendars seamlessly across all platforms and prevent double bookings
Veterinary & Healthcare Clinics
Never double-book appointments and keep patient schedules perfectly synchronized
Fitness & Wellness Studios
Manage class schedules across multiple calendars and instructor availability
Real Estate Agencies
Coordinate property showings and open houses across teams and client schedules
Individuals & Families
Keep all personal calendars in sync and never miss family events or appointments
Pet Care Professionals
Manage grooming and sitting appointments across your personal and business calendars
Service Providers
Sync dispatch calendars with client availability and manage work schedules efficiently
Powerful Dashboard for Everyone
Developers manage integrations and monitor sync health. Users control their calendars and privacy settings.
Developer Dashboard
Manage APIs and monitor sync health
Total Connections
1,234
Sync Health
99.9%
API Key
cs_live_abc123xyz...
Recent Activity
- 5 new connections this week
- 0 sync failures
- API rate limit: 95% available
User Dashboard
Manage your connected calendars
Google Calendar
Connected & Syncing
Last synced: 2 minutes ago
Microsoft 365
Connected & Syncing
Last synced: 1 minute ago
Next Steps
- 8 events synced this week
- All calendars in sync
- Add another calendar
How It Works
From app creation to real-time calendar synchronization in five simple steps
Developer Creates App
Set up your app and get an API key
User Connects Calendar
End user clicks 'Connect Calendar'
OAuth Flow
User authorizes access to their calendar
Real-Time Sync
Calendars sync automatically both ways
Access Data
Developer polls API or receives webhooks
Developer Creates App
Set up your app and get an API key
User Connects Calendar
End user clicks 'Connect Calendar'
OAuth Flow
User authorizes access to their calendar
Real-Time Sync
Calendars sync automatically both ways
Access Data
Developer polls API or receives webhooks
Frequently Asked Questions
Find answers to common questions from developers and users.
For Developers
What API rate limits should I expect?
Calendar-Sync provides generous rate limits: 1,000 requests/minute for API endpoints and real-time webhooks for instant updates. Contact sales for higher limits on Enterprise plans.
Do you support real-time webhooks?
Yes, we provide webhook support for Google Calendar and Microsoft 365. Webhooks deliver events in real-time, eliminating the need for frequent polling and improving latency from minutes to seconds.
How do I handle conflicts when events change on both sides?
Calendar-Sync uses a last-writer-wins conflict resolution strategy. All conflicts are logged in the dashboard, and you can replay sync for specific events if needed. See our conflict resolution docs for details.
What happens if a user revokes access?
If a user revokes access through their provider (Google/Microsoft), that connection is immediately marked as inactive. We stop attempting to sync and delete all stored tokens. You receive a webhook notification of the revocation.
For Users
Is my calendar data secure?
Yes. Calendar-Sync uses industry-standard encryption (TLS in transit, AES-256 at rest). OAuth tokens are encrypted with a master key and never exposed. We are SOC 2 Type II compliant.
What happens if I disconnect?
Disconnecting will stop all syncing for that calendar and permanently delete your stored OAuth tokens. Your calendar data remains in Google/Microsoft. You can reconnect at any time.
Can I use this with multiple calendar providers at once?
Yes. You can connect both Google and Microsoft calendars simultaneously. Events from all connected calendars will sync together, and you can manage them from one place.
Do you store my Google or Microsoft passwords?
No, we never store passwords. We use OAuth 2.0, which means you authenticate directly with Google or Microsoft. We only store encrypted OAuth tokens, which are separate from your password.
Ready to Sync?
Join developers and teams already using Calendar-Sync
For Developers
Create a free account to get your API key and start building
Get Started Building