Capabilities
Built by sysadmins, for sysadmins
Every feature exists because a Windows admin needed it. No bloat, no SaaS dependencies, no telemetry.
Microsoft Graph API
Contacts.ReadWrite and User.Read.All via Graph SDK v5. No EWS, no legacy protocols, no deprecation risk.
WinUI 3 Admin Dashboard
Native Windows app for configuration, manual sync triggers, real-time progress, and full sync history.
High-Performance Sync
Delta Query fetches only changed users. Up to 10 mailboxes processed in parallel with JSON batching, automatic retry, and exponential backoff.
Enterprise-Grade Security
Offline RSA-2048 signed license keys verified locally. Certificate-based Entra ID auth via Azure.Identity. Keys encrypted at rest with DPAPI.
Open Extension Correlation
Contacts tagged with the com.itbaer.cync Open Extension. Renames and email changes handled correctly — no duplicates.
Server Core Support
Installs on Server Core (no GUI). Administer remotely via gRPC-over-HTTPS with Windows-integrated authentication.
Full Sync History
Every sync run stored in SQLite: timestamps, users processed, contacts created/updated/deleted, errors.
Flexible Field & Photo Sync
Toggle individual fields on or off — name, phone, department, address, and more. Optionally sync Entra ID profile photos to contacts.
Source Filtering
Sync all Entra ID users, or restrict to specific groups. Exclude by department or UPN pattern.
Smart Target Management
Auto-sync target groups from Entra ID with automatic member add/remove, or import targets via CSV for easy migration.
Enterprise Deployment
WiX v5 MSI with silent install (/quiet), service registration, and offline prerequisites. Upgrade by re-running the MSI — no manual re-deployment.
Windows Event Log
All sync events, errors, and status changes are written to the Windows Event Log. Integrate with your existing SIEM or monitoring stack.
Architecture
Runs entirely on your infrastructure
A .NET 10 Windows Service communicating with Microsoft Graph API, with local SQLite storage and offline RSA-signed license verification.
Cync.Service
Sync engine, gRPC server, license enforcer
.NET 10 · gRPC · EF Core
Cync.UI
WinUI 3 admin dashboard, local or remote
WinUI 3 · Windows App SDK
Cync.Installer
MSI with service registration & offline prereqs
WiX v5 · BootstrapperReady to replace your scripts?
Download CYNC and see contacts land in mailboxes within minutes. Free for up to 10 users.