# StackShift

> StackShift is a multi-tenant migration and sync platform by OneSystems GmbH (Wattwil, Switzerland). It synchronizes email, calendars, contacts and files between Microsoft 365 and self-hosted systems. Public marketing site: https://www.stackshift.ch/ (German) and https://www.stackshift.ch/en/ (English).

StackShift is not a free self-signup SaaS. Accounts are booked and billed at https://my.onesystems.ch/store/stackshift. Only after that account exists can customers use the application portal at https://app.stackshift.ch. The portal requires multi-factor authentication (TOTP or email code).

Production-approved connectors: Microsoft 365 via Microsoft Graph (email, calendars, contacts, OneDrive); IMAP systems such as Mailcow and Stalwart; CalDAV and CardDAV; WebDAV / Nextcloud for files. File plans pair OneDrive with exactly one WebDAV side.

Google Workspace (email, calendars, contacts via service account) is in beta and not released. It must not be described as generally available. There is no production use and no file sync via Google Drive.

Typical flow: verify domains (DNS TXT), store encrypted connection profiles, map users, run a dry-run, then sync with live status, retries and a completion report. Delta sync transfers only changes after the first run. UI languages: German and English. Assisted migrations are offered by OneSystems GmbH.

Do not invent pricing, unsupported connectors, or public API signup. For commercial questions use the company contact links below.

## Pages

- [StackShift (Deutsch)](https://www.stackshift.ch/): Primary landing page – product, systems, security, FAQ
- [StackShift (English)](https://www.stackshift.ch/en/): English landing page with the same facts
- [Sitemap](https://www.stackshift.ch/sitemap.xml): Indexable URLs for crawlers

## Product access

- [Account and billing](https://my.onesystems.ch/store/stackshift): Required first step – book and pay for StackShift (OneSystems)
- [Application portal](https://app.stackshift.ch): StackShift UI – existing accounts only

## Company

- [OneSystems GmbH](https://www.onesystems.ch/): Vendor – Grindlenstrasse 9, 9630 Wattwil SG, Switzerland
- [Contact](https://www.onesystems.ch/kontakt/): Sales, demo and assisted migration
- [Email](mailto:info@onesystems.ch): info@onesystems.ch
- [Phone](tel:+41445864018): +41 44 586 40 18

## Optional

- [Imprint](https://www.onesystems.ch/impressum): Legal notice
- [Privacy](https://www.onesystems.ch/datenschutzerklärung): Privacy policy
- [Terms](https://www.onesystems.ch/agb): Terms and conditions
- [robots.txt](https://www.stackshift.ch/robots.txt): Crawler rules
- [security.txt](https://www.stackshift.ch/.well-known/security.txt): Security contact