SilentSuite
End-to-end encrypted sync for calendar, contacts and tasks.
About
SilentSuite
SilentSuite is an open-source, end-to-end encrypted, zero-knowledge sync suite for calendars, contacts, tasks, and other private productivity data. It gives you the convenience of cloud synchronization without giving the server access to the contents of your life.
Your data is encrypted on your device before it is uploaded. The server stores encrypted data, never plaintext, and your encryption keys remain on your devices. This means SilentSuite cannot read, analyze, or monetize your calendar events, address book, or tasks. Privacy is enforced by the architecture, not only promised in a policy.
Key features
- Zero-knowledge, end-to-end encrypted sync: Plaintext stays off the server and encryption keys stay on-device.
- Calendars, contacts, and tasks: Keep essential personal information synchronized across supported devices and applications.
- Works with existing apps: A CalDAV and CardDAV bridge lets you connect compatible calendar, contacts, and task clients instead of forcing you into a closed ecosystem.
- Android and web access: Use SilentSuite from its Android app or web interface, with broader compatibility provided through the bridge.
- Open source: The server, web app, bridge, and self-hosting components are publicly auditable.
- Hosted or self-hosted: Use the managed silentsuite.io service for convenience or deploy SilentSuite on your own infrastructure for greater control.
- Built on proven foundations: SilentSuite continues the Etebase/EteSync open-source lineage as a fork, modernized and developed as an accessible privacy-first product.
Use cases
SilentSuite is designed for individuals, families, privacy-conscious professionals, and self-hosters who want to:
- Synchronize calendars without exposing event details to a cloud provider.
- Keep contacts available across devices without feeding an advertising or profiling ecosystem.
- Manage private tasks and personal planning data securely.
- Continue using familiar DAV-compatible applications while adding end-to-end encrypted synchronization.
- Replace proprietary productivity clouds with an open-source alternative.
- Run a private synchronization service on infrastructure they control.
What makes SilentSuite stand out
Most cloud productivity services can technically access the information stored on their servers. SilentSuite takes a different approach, the server is designed not to know what you are storing. Your private data is encrypted before it leaves your device, and only your devices hold the keys needed to decrypt it.
Unlike products that require users to abandon their preferred applications, SilentSuite also supports open standards through its DAV bridge. This combines strong zero-knowledge encryption with the flexibility of existing calendar, contacts, and task clients.
Ready to launch?
Submit your product and get discovered by builders and creators worldwide.
Launch Now
FounderPlaybooks.
What other founders did to grow.
2722 dispatches from hundreds of founders, pulled from the week's best podcasts.
We optimize as a true north the business for long-term revenue and I say long-term revenue not short-term revenue because there's a lot of revenue we forgo and don't want to take because we believe it will squeeze you know the funnel in a way that we're not interested in.
Optimize for long-term revenue even when it means forgoing short-term gains
LinkedIn explicitly declines revenue that would optimize a short-term metric at the cost of member trust or long-term retention. Pricing experiments are evaluated on a 5-year revenue model, not just the first year. This long-term revenue orientation is enforced structurally: there's allocated 'revenue we won't take' and the team has permission to decline short-term extraction tactics. The result is a subscription business running at several billion dollars in annual run rate.
I typically don't like people to optimize their campaigns for purchases or trial complete — those tend to happen way too far out. If you're a 7-day trial, for Google to get that data back seven days later is just too much lag. Optimizing for those earlier signals — most of the time a start trial — is the right approach.
Optimize for trial starts not purchases — subscription purchase events lag too far for UAC to learn
Google UAC's algorithm needs conversion signals within a short window to optimize bidding effectively. For subscription apps, final purchase events are delayed by the trial period — meaning the algorithm flies blind during the most critical early optimization phase. Setting the optimization event to 'trial start' gives faster feedback while still serving as a strong proxy for downstream revenue.
There's a play for whatever you're stuck on.
Read all 2722 playbooks